Merge branch 'develop' into feature/remove_nasm

do not append to gdb.run

.clang-format

@@ -20,7 +20,7 @@ AlignTrailingComments: true
 AllowAllParametersOfDeclarationOnNextLine: false
 AllowShortCaseLabelsOnASingleLine: false
 AllowShortFunctionsOnASingleLine: None
-AllowShortIfStatementsOnASingleLine: Never
+AllowShortIfStatementsOnASingleLine: Always
 AllowShortLoopsOnASingleLine: true
 AllowShortBlocksOnASingleLine: Always
 AlwaysBreakAfterDefinitionReturnType: None

.gdb.debug

@@ -1,3 +0,0 @@
-symbol-file ./mentos/kernel.bin
-exec-file ./mentos/kernel.bin
-target remote localhost:1234

.github/workflows/main.yml

@@ -1,52 +0,0 @@
-name: Main
-on:
-  push:
-    branches-ignore:
-      - "releases/**"
-    paths-ignore:
-      - "**.md"
-      - ".gitignore"
-  pull_request:
-    paths-ignore:
-      - "**.md"
-      - ".gitignore"
-jobs:
-  doxygen:
-    name: Doxygen
-    runs-on: ubuntu-latest
-    steps:
-      - name: Clone repo
-        uses: actions/checkout@v2
-
-      - name: Install Doxygen Ubuntu
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y doxygen nasm
-
-      - name: Generate documentation
-        run: |
-          cmake -B build -D DOXYGEN_WARN_AS_ERROR=NO
-          cmake --build build --target doxygen_doc
-
-  test:
-    name: Build
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest]
-
-    runs-on: ${{ matrix.os }}
-    steps:
-      - name: Clone repo
-        uses: actions/checkout@v2
-
-      - name: Install NASM Ubuntu
-        if: matrix.os == 'ubuntu-latest'
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y nasm
-
-      - name: Build
-        run: |
-          cmake -B build
-          cmake --build build --parallel 2

.github/workflows/ubuntu.yml

@@ -0,0 +1,86 @@
+name: Ubuntu
+on:
+    push:
+        branches-ignore:
+            - "releases/**"
+        paths-ignore:
+            - "**.md"
+            - ".gitignore"
+            - "**/macos.yml"
+            - "**/windows.yml"
+    pull_request:
+        paths-ignore:
+            - "**.md"
+            - ".gitignore"
+            - "**/macos.yml"
+            - "**/windows.yml"
+jobs:
+    doxygen:
+        name: Doxygen
+        runs-on: ubuntu-latest
+        steps:
+            - name: Clone repository
+              uses: actions/checkout@v3
+            - name: Install dependencies
+              run: |
+                  sudo apt-get update
+                  sudo apt-get install -y doxygen nasm
+            - name: Generate documentation
+              run: |
+                  cmake -B build -D DOXYGEN_WARN_AS_ERROR=NO
+                  cmake --build build --target mentos_documentation
+    build:
+        name: Build
+        strategy:
+            fail-fast: false
+            matrix:
+                include: [
+                        # You can access the following values via ${{ matrix.??? }}
+                        #
+                        #   pkgs         : apt-get package names.  It can include multiple package names which are delimited by space.
+                        #   cc           : C compiler executable.
+                        #   cxx          : C++ compiler executable for `make ctocpptest`.
+                        #   x32          : Set 'true' if compiler supports x32.  Otherwise, set 'false'.
+                        #                  Set 'fail' if it supports x32 but fails for now.  'fail' cases must be removed.
+                        #   x86          : Set 'true' if compiler supports x86 (-m32).  Otherwise, set 'false'.
+                        #                  Set 'fail' if it supports x86 but fails for now.  'fail' cases must be removed.
+                        #   cxxtest      : Set 'true' if it can be compiled as C++ code.  Otherwise, set 'false'.
+                        #   freestanding : Set 'true' if it can be compiled and execute freestanding code.  Otherwise, set 'false'.
+                        #                  Usually, it requires Linux, x86_64 and gcc/g++.
+                        #   os           : GitHub Actions YAML workflow label.  See https://github.com/actions/virtual-environments#available-environments
+                        # gcc
+                        { pkgs: "nasm", cc: gcc, cxx: g++, os: ubuntu-latest },
+                        { pkgs: "gcc-12 g++-12 nasm", cc: gcc-12, cxx: g++-12, os: ubuntu-22.04 },
+                        { pkgs: "gcc-11 g++-11 nasm", cc: gcc-11, cxx: g++-11, os: ubuntu-22.04 },
+                        { pkgs: "gcc-10 g++-10 nasm", cc: gcc-10, cxx: g++-10, os: ubuntu-22.04 },
+                        { pkgs: "gcc-9 g++-9 nasm", cc: gcc-9, cxx: g++-9, os: ubuntu-22.04 },
+                        { pkgs: "gcc-8 g++-8 nasm", cc: gcc-8, cxx: g++-8, os: ubuntu-20.04 },
+                        { pkgs: "gcc-7 g++-7 nasm", cc: gcc-7, cxx: g++-7, os: ubuntu-20.04 },
+                        # clang
+                        { pkgs: "nasm", cc: clang, cxx: clang++, os: ubuntu-latest },
+                        { pkgs: "clang-14 nasm", cc: clang-14, cxx: clang++-14, os: ubuntu-22.04 },
+                        { pkgs: "clang-13 nasm", cc: clang-13, cxx: clang++-13, os: ubuntu-22.04 },
+                        { pkgs: "clang-12 nasm", cc: clang-12, cxx: clang++-12, os: ubuntu-22.04 },
+                        { pkgs: "clang-11 nasm", cc: clang-11, cxx: clang++-11, os: ubuntu-22.04 },
+                        { pkgs: "clang-10 nasm", cc: clang-10, cxx: clang++-10, os: ubuntu-20.04 },
+                        { pkgs: "clang-9 nasm", cc: clang-9, cxx: clang++-9, os: ubuntu-20.04 },
+                        { pkgs: "clang-8 nasm", cc: clang-8, cxx: clang++-8, os: ubuntu-20.04 },
+                        { pkgs: "clang-7 nasm", cc: clang-7, cxx: clang++-7, os: ubuntu-20.04 },
+                    ]
+        runs-on: ${{ matrix.os }}
+        # Set environment variables
+        env:
+            # We globally set CC and CXX.
+            CC: ${{ matrix.cc }}
+            CXX: ${{ matrix.cxx }}
+        steps:
+            - name: Clone repository
+              uses: actions/checkout@v3
+            - name: Install dependencies
+              run: |
+                  sudo apt-get update
+                  sudo apt-get install -y ${{ matrix.pkgs }}
+            - name: Build
+              run: |
+                  cmake -B build
+                  cmake --build build --parallel 2

.gitignore

@@ -118,5 +118,5 @@ files/bin/**
 # ISO creation files.
 iso/boot/*.bin
 
-# Visual Studio Code
-.vscode
+# ClangD stuff.
+.cache

.vscode/launch.json

@@ -0,0 +1,13 @@
+{
+    "configurations": [
+        {
+            "type": "gdb",
+            "request": "attach",
+            "name": "(gdb) Attach",
+            "target": "localhost:1234",
+            "remote": true,
+            "cwd": "${workspaceRoot}/build",
+            "valuesFormatting": "parseText"
+        }
+    ]
+}

CMakeLists.txt

@@ -1,6 +1,7 @@
 # =============================================================================
 # Set the minimum required version of cmake.
 cmake_minimum_required(VERSION 3.1...3.22)
+
 # Initialize the project.
 project(mentos C ASM)
 
@@ -17,7 +18,7 @@ endif()
 # =============================================================================
 # DOCUMENTATION
 # =============================================================================
-add_subdirectory(doc/doxygen)
+add_subdirectory(doc)
 
 # =============================================================================
 # OS-SPECIFIC COMPILERS
@@ -28,18 +29,6 @@ message(STATUS "Crosscompiling : ${CMAKE_CROSSCOMPILING}")
 message(STATUS "System name    : ${CMAKE_HOST_SYSTEM_NAME}")
 message(STATUS "Kernel version : ${CMAKE_SYSTEM_VERSION}")
 if((${CMAKE_HOST_SYSTEM_NAME} STREQUAL "Darwin") OR APPLE)
-    # Set the Apple MacOSx compilers.
-    if(CMAKE_VERSION VERSION_LESS "3.6.0")
-        include(CMakeForceCompiler)
-        cmake_force_c_compiler(i386-elf-gcc Clang)
-        cmake_force_cxx_compiler(i386-elf-g++ Clang)
-    else()
-        set(CMAKE_C_COMPILER i386-elf-gcc)
-        set(CMAKE_CXX_COMPILER i386-elf-g++)
-        set(CMAKE_AR i386-elf-ar)
-    endif()
-    # Speicfy the linker.
-    set(CMAKE_LINKER i386-elf-ld)
     # Specify the linker flags.
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -nostdlib")
 elseif((${CMAKE_HOST_SYSTEM_NAME} STREQUAL "Windows") OR WIN32)
@@ -68,8 +57,58 @@ else()
     else()
         # set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -sdl)
     endif()
+    # Speicfy the linker.
+    set(CMAKE_LINKER ld)
 endif()
 
+# Enable the assembly language.
+enable_language(ASM)
+# Find the NASM compiler.
+find_program(ASM_COMPILER NAMES nasm HINTS /usr/bin/ /usr/local/bin/)
+# Mark the variable ASM_COMPILER as advanced.
+mark_as_advanced(ASM_COMPILER)
+# Check that we have found the compiler.
+if(NOT ASM_COMPILER)
+    message(FATAL_ERROR "ASM compiler not found!")
+endif(NOT ASM_COMPILER)
+
+# Set the assembly compiler flags.
+set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -m32")
+# Warning flags.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
+# Disable some specific warnings.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-braces")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-command-line-argument")
+# Set the compiler options.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ffreestanding")
+if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
+endif()
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
+endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
+
 # =============================================================================
 # COMPILATION
 # =============================================================================
@@ -93,7 +132,7 @@ add_custom_target(filesystem
     COMMAND echo '============================================================================='
     COMMAND mkdir -p ${CMAKE_SOURCE_DIR}/files/proc
     COMMAND mkdir -p ${CMAKE_SOURCE_DIR}/files/dev
-    COMMAND mke2fs -L 'rootfs' -N 0 -d ${CMAKE_SOURCE_DIR}/files -m 5 -r 1 -t ext2 -v -F ${CMAKE_BINARY_DIR}/rootfs.img 32M
+    COMMAND mke2fs -L 'rootfs' -N 0 -d ${CMAKE_SOURCE_DIR}/files -b 4096 -m 5 -r 1 -t ext2 -v -F ${CMAKE_BINARY_DIR}/rootfs.img 32M
     COMMAND echo '============================================================================='
     COMMAND echo 'Done!'
     COMMAND echo '============================================================================='
@@ -134,7 +173,7 @@ set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -vga std)
 # Set the amount of memory.
 set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -m 1096M)
 # Set the EXT2 drive.
-set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -drive file=${CMAKE_BINARY_DIR}/rootfs.img,format=raw)
+set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -drive file=${CMAKE_BINARY_DIR}/rootfs.img,format=raw,index=0,media=disk)
 
 # =============================================================================
 # Booting with QEMU for fun
@@ -144,8 +183,8 @@ set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -drive file=${CMAKE_BINARY_DIR}/rootfs.img,
 add_custom_target(
     qemu
     COMMAND test -e ${CMAKE_BINARY_DIR}/rootfs.img || ${CMAKE_COMMAND} -E cmake_echo_color --red "No filesystem file detected, you need to run: make filesystem"
-    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -kernel ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin
-    DEPENDS kernel-bootloader.bin
+    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -kernel ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin
+    DEPENDS kernel_bootloader.bin
 )
 
 # =============================================================================
@@ -155,16 +194,18 @@ add_custom_target(
 # First, we need to generate a GDB file containing all the symbols of all our
 # executables.
 add_custom_target(
-    .gdbinit
+    gdbinit
     BYPRODUCTS ${CMAKE_BINARY_DIR}/.gdbinit
     COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/mentos/kernel.bin > ${CMAKE_BINARY_DIR}/.gdbinit
-    COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin >> ${CMAKE_BINARY_DIR}/.gdbinit
+    COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin >> ${CMAKE_BINARY_DIR}/.gdbinit
     COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/programs/tests/test_* >> ${CMAKE_BINARY_DIR}/.gdbinit
     COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/programs/prog_* >> ${CMAKE_BINARY_DIR}/.gdbinit
     COMMAND echo "break boot.c: boot_main" >> ${CMAKE_BINARY_DIR}/.gdbinit
     COMMAND echo "break kernel.c: kmain" >> ${CMAKE_BINARY_DIR}/.gdbinit
-    COMMAND echo "target remote localhost:1234" >> ${CMAKE_BINARY_DIR}/.gdbinit
-    DEPENDS kernel-bootloader.bin
+    # Create the GDB connection file.
+    COMMAND echo "target remote localhost:1234" > ${CMAKE_BINARY_DIR}/gdb.run
+    DEPENDS ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin
+    DEPENDS ${CMAKE_BINARY_DIR}/mentos/kernel.bin
     DEPENDS all_programs
     DEPENDS all_tests
     DEPENDS libc
@@ -182,8 +223,8 @@ add_custom_target(
     COMMAND echo "in THIS same folder, and just type :\n"
     COMMAND printf "    cgdb -q -iex %q" "add-auto-load-safe-path ."
     COMMAND echo "\n\n"
-    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -s -S -kernel ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin
-    DEPENDS kernel-bootloader.bin
+    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -s -S -kernel ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin
+    DEPENDS kernel_bootloader.bin
     DEPENDS .gdbinit
 )
 
@@ -195,9 +236,9 @@ add_custom_target(
 add_custom_target(
   cdrom.iso
   COMMAND cp -rf ${CMAKE_SOURCE_DIR}/iso .
-  COMMAND cp ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin ${CMAKE_BINARY_DIR}/iso/boot
+  COMMAND cp ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin ${CMAKE_BINARY_DIR}/iso/boot
   COMMAND grub-mkrescue -o ${CMAKE_BINARY_DIR}/cdrom.iso ${CMAKE_BINARY_DIR}/iso
-  DEPENDS kernel-bootloader.bin
+  DEPENDS kernel_bootloader.bin
 )
 
 # This third target runs the emualtor, but this time, the kernel binary file is

README.md

@@ -1,10 +1,33 @@
-# MentOS
+# MentOS (Mentoring Operating System)
 
 [![forthebadge](https://forthebadge.com/images/badges/built-with-love.svg)](https://forthebadge.com)
 [![forthebadge](https://forthebadge.com/images/badges/made-with-c.svg)](https://forthebadge.com)
 [![forthebadge](https://forthebadge.com/images/badges/for-you.svg)](https://forthebadge.com)
 
-## 1. What is MentOS
+[![Ubuntu](https://github.com/mentos-team/MentOS/actions/workflows/ubuntu.yml/badge.svg)](https://github.com/mentos-team/MentOS/actions/workflows/ubuntu.yml)
+
+## Table of Contents
+
+- [MentOS (Mentoring Operating System)](#mentos-mentoring-operating-system)
+  - [Table of Contents](#table-of-contents)
+  - [What is MentOS](#what-is-mentos)
+  - [Implemented features](#implemented-features)
+  - [Prerequisites](#prerequisites)
+    - [Installing the prerequisites](#installing-the-prerequisites)
+  - [Compiling MentOS](#compiling-mentos)
+  - [Generating the EXT2 filesystem](#generating-the-ext2-filesystem)
+  - [Running MentOS](#running-mentos)
+  - [Running MentOS from GRUB](#running-mentos-from-grub)
+  - [Running and adding new programs to MentOS](#running-and-adding-new-programs-to-mentos)
+    - [Create a new program](#create-a-new-program)
+    - [Add the new program to the list of compiled sources](#add-the-new-program-to-the-list-of-compiled-sources)
+    - [Running a program or a test](#running-a-program-or-a-test)
+  - [Kernel logging](#kernel-logging)
+  - [Change the scheduling algorithm](#change-the-scheduling-algorithm)
+  - [Debugging the kernel](#debugging-the-kernel)
+  - [Contributors](#contributors)
+
+## What is MentOS
 
 MentOS (Mentoring Operating System) is an open source educational operating
 system. The goal of MentOS is to provide a project environment that is realistic
@@ -26,7 +49,10 @@ Parts of MentOS are inherited or inspired by a similar educational operating
 system called [DreamOs](https://github.com/dreamos82/DreamOs) written by Ivan
 Gualandri.
 
-## 2. Implemented features
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Implemented features
+
 Follows the list of implemented features:
 
 **Processes and Events**
@@ -61,24 +87,28 @@ Follows the list of implemented features:
  - [x] Video drivers;
  - [ ] VGA drivers;
 
+**Inter-Process Communication (IPC)**
+ - [X] Semaphore
+ - [ ] Message queue
+ - [ ] Shared memory
+ - [ ] Named pipe
+
 I will try to keep it updated...
 
-## 3. Prerequisites
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Prerequisites
 
 MentOS is compatible with the main **unix-based** operating systems. It has been
-tested with *Ubuntu*, *WSL1*, *WSL2*, and  *MacOS*.
+tested with *Ubuntu*, and under Windows with *WSL1* and *WSL2*.
 
-### 3.1. Generic Prerequisites
+For **compiling** the system we need:
 
-#### 3.1.1. Compile
-
-For compiling the system:
-
- - nasm
+ - git
  - gcc
+ - nasm
  - make
  - cmake
- - git
  - ccmake (suggested)
  - e2fsprogs (should be already installed)
 
@@ -87,41 +117,29 @@ Under **MacOS**, for compiling, you have additional dependencies:
  - i386-elf-binutils
  - i386-elf-gcc
 
-#### 3.1.2. Execute
-
-To execute the operating system, you need to install:
+For **executing** the operating system we need:
 
  - qemu-system-i386 (or qemu-system-x86)
 
-#### 3.1.3. Debug
-
-For debugging we suggest using:
+For **debugging** we suggest using:
 
  - gdb or cgdb
 
-### 3.2. installation Prerequisites
+### Installing the prerequisites
 
 Under **Ubuntu**, you can type the following commands:
 
 ```bash
 sudo apt-get update && sudo apt-get upgrade -y
-sudo apt-get install -y build-essential git cmake qemu-system-x86 nasm e2fsprogs
+sudo apt-get install -y git build-essential nasm make cmake cmake-curses-gui e2fsprogs
+sudo apt-get install -y qemu-system-x86
 sudo apt-get install -y gdb cgdb
 ```
 Note: Older versions might have `qemu-system-i386` instead of `qemu-system-x86`.
 
-Under **MacOS** you also need to install the i386-elf cross-compiler. The
-simplest installation method is through Homebrew package manager.
-Install [Homebrew](https://brew.sh/index_it) if you don't already have it, and
-then type the following commands:
+*[Back to the Table of Contents](#table-of-contents)*
 
-```bash
-brew update && brew upgrade
-brew install i386-elf-binutils i386-elf-gcc git cmake qemu nasm e2fsprogs
-brew install gdb cgdb #<- for debug only
-```
-
-## 4. Compiling MentOS and generating the EXT2 filesystem
+## Compiling MentOS
 
 Compile MentOS with:
 
@@ -133,14 +151,20 @@ cmake ..
 make
 ```
 
-Then, generate the EXT2 filesystem with:
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Generating the EXT2 filesystem
+
+Generate the EXT2 filesystem with:
 
 ```bash
 make filesystem
 ```
 you just need to generate the filesystem once. If you change a `program` you need to re-generate the entire filesystem with `make filesystem`, but this will override any changes you made to the files inside the `rootfs.img`. In the future I will find a way to update just the `/usr/bin` directory and the programs.
 
-## 5. Running MentOS
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Running MentOS
 
 Boot MentOS with qemu:
 
@@ -150,11 +174,93 @@ make qemu
 
 To login, use one of the usernames listed in `files/etc/passwd`.
 
-## 6. Kernel logging
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Running MentOS from GRUB
+
+For booting MentOS from GRUB in QEMU we need the following tools:
+
+ - xorriso
+ - grub-mkrescue (from grub-common)
+
+We also need `grub-pc-bin`, otherwise GRUB won't start in QEMU.
+
+Which can be installed in Ubuntu with the following command:
+```bash
+sudo apt-get update && sudo apt-get upgrade -y
+sudo apt-get install -y grub-common grub-pc-bin xorriso
+```
+
+Boot MentOS with qemu through GRUB by calling:
+
+```bash
+make qemu-grub
+```
+
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Running and adding new programs to MentOS
+
+This section explains how to add a new program to MentOS, and also how to run programs in mentos. It also explains how to add new tests, which are located in the `programs/tests` folder.
+
+### Create a new program
+
+Head to the `programs` (or the `programs/tests`) folder. Create and open a new program, for instance a file called `hello_world.c`, with your preferred editor, and add this content to the file:
+```C
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+    printf("Hello, World!\n\n");
+    return 0;
+}
+```
+
+### Add the new program to the list of compiled sources
+Now we can add the program to the list of files which are compiled and placed inside MentOS filesystem.
+The following procedure is the same for both `programs` and `programs/tests`, what changes is which `CMakeLists.txt` file we modify.
+
+You need to modify the `CMakeLists.txt` file, either `programs/CMakeLists.txt` or `programs/tests/CMakeLists.txt`, and add your program to the list of files to be compiled:
+```Makefile
+# Add the executables (manually).
+set(PROGRAMS
+    init.c
+    ...
+    hello_world.c
+)
+```
+or
+```Makefile
+# Add the executables (manually).
+set(TESTS
+    t_mem.c
+    ...
+    hello_world.c
+)
+```
+
+That's it, the `hello_world.c` file will be compiled and will appear inside the `/bin` or `/bin/tests` folder of MentOS.
+
+### Running a program or a test
+Once you login into MentOS, if you placed your source code in `programs`, you can execute the program by simply typing:
+```bash
+hello_world
+```
+because the file resides in `/bin`, and that folder is listed in the `PATH` environment variable.
+
+Now, if you placed your source code inside the `programs/tests` folder, the executable will end up inside the `/bin/tests` folder.
+However, the `/bin/tests` folder is not listed in `PATH`, so, if you want to execute a test from that folder you need to specify the full path:
+```bash
+/bin/tests/hello_world
+```
+
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Kernel logging
 The kernel provides ways of printing logging messages *from* inside the kernel code *to* the bash where you executed the `make qemu`.
 
 These *logging* functions are:
-```C++
+```C
 #define pr_emerg(...)
 #define pr_alert(...)
 #define pr_crit(...)
@@ -167,7 +273,7 @@ These *logging* functions are:
 ```
 
 You use them like you would use a `printf`:
-```C++
+```C
     if (fd < 0) {
         pr_err("Failed to open file '%s', received file descriptor %d.\n", filename, fd);
         return 1;
@@ -177,7 +283,7 @@ You use them like you would use a `printf`:
 By default only message that goes from `pr_notice` included down to `pr_emerg` are displayed.
 
 Each logging function (they are actually macros) is a wrapper that automatically sets the desired **log level**. Each log level is identified by a number, and declared as follows:
-```C++
+```C
 #define LOGLEVEL_DEFAULT (-1) ///< default-level messages.
 #define LOGLEVEL_EMERG   0    ///< system is unusable.
 #define LOGLEVEL_ALERT   1    ///< action must be taken immediately.
@@ -190,41 +296,58 @@ Each logging function (they are actually macros) is a wrapper that automatically
 ```
 
 You can change the logging level by including the following lines at the beginning of your source code:
-```C++
+```C
 // Include the kernel log levels.
 #include "sys/kernel_levels.h"
 /// Change the header.
 #define __DEBUG_HEADER__ "[ATA   ]"
 /// Set the log level.
 #define __DEBUG_LEVEL__ LOGLEVEL_INFO
+// Include the debuggin header.
+#include "io/debug.h"
 ```
 This example sets the `__DEBUG_LEVEL__`, so that all the messages from `INFO` and below are shown. While `__DEBUG_HEADER__` is just a string that is automatically prepended to your message, helping you identifying from which code the message is coming from.
 
-## 7. Change the scheduling algorithm
+*[Back to the Table of Contents](#table-of-contents)*
 
-MentOS provides three different scheduling algorithms:
+## Change the scheduling algorithm
 
- - Round-Robin
- - Priority
- - Completely Fair Scheduling
+MentOS supports scheduling algorithms for aperiodic:
 
-If you want to change the scheduling algorithm:
+ - Round-Robin (RR)
+ - Highest Priority
+ - Completely Fair Scheduling (CFS)
+ - Aperiodic Earliest Deadline First (AEDF)
+
+It also supports periodic algorithms:
+
+ - Earliest Deadline First (EDF)
+ - Rate Monotonic (RM)
+
+If you want to change the scheduling algorithm, to Round-Robin (RR) for instance:
 
 ```bash
-
 cd build
-
-# Round Robin scheduling algorithm
 cmake -DSCHEDULER_TYPE=SCHEDULER_RR ..
-# Priority scheduling algorithm
-cmake -DSCHEDULER_TYPE=SCHEDULER_PRIORITY ..
-# Completely Fair Scheduling algorithm
-cmake -DSCHEDULER_TYPE=SCHEDULER_CFS ..
-
 make
 make qemu
 ```
 
+or you can activate one of the others:
+
+```bash
+# Highest Priority
+cmake -DSCHEDULER_TYPE=SCHEDULER_PRIORITY ..
+# Completely Fair Scheduling (CFS)
+cmake -DSCHEDULER_TYPE=SCHEDULER_CFS      ..
+# Earliest Deadline First (EDF)
+cmake -DSCHEDULER_TYPE=SCHEDULER_EDF      ..
+# Rate Monotonic (RM)
+cmake -DSCHEDULER_TYPE=SCHEDULER_RM       ..
+# Aperiodic Earliest Deadline First (AEDF)
+cmake -DSCHEDULER_TYPE=SCHEDULER_AEDF     ..
+```
+
 Otherwise you can use `ccmake`:
 
 ```bash
@@ -244,8 +367,7 @@ ENABLE_BUDDY_SYSTEM              OFF
 SCHEDULER_TYPE                   SCHEDULER_RR
 ```
 
-Select SCHEDULER_TYPE, and type Enter to scroll the three available algorithms
-(SCHEDULER_RR, SCHEDULER_PRIORITY, SCHEDULER_CFS). Afterwards,
+Select SCHEDULER_TYPE, and type Enter to scroll the three available algorithms (SCHEDULER_RR, SCHEDULER_PRIORITY, SCHEDULER_CFS, SCHEDULER_EDF, SCHEDULER_RM, SCHEDULER_AEDF). Afterwards, you need to
 
 ```bash
 <press c>
@@ -254,7 +376,9 @@ make
 make qemu
 ```
 
-## 8. Use Debugger
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Debugging the kernel
 
 If you want to use GDB to debug MentOS, first you need to compile everything:
 
@@ -264,33 +388,38 @@ cmake ..
 make
 ```
 
-Then, you need to generate a file called `.gdbinit` placed inside the `build` directory, which will tell **gdb** which *object* file he needs to read in order to allow proper debugging.
+Then, you need to generate a file called `.gdbinit` placed inside the `build` directory, which will tell **gdb** which *object* file he needs to read in order to allow proper debugging. Basically, it provides for each binary file, the location of their `.text` section. To generate the file, just execute:
 ```bash
-make gdb_file
+make gdbinit
 ```
 
 Finally, you run qemu in debugging mode with:
 ```bash
 make qemu-gdb
 ```
+
 If you did everything correctly, you should see an empty QEMU window. Basically, QEMU is waiting for you to connect *remotely* with gdb. Anyway, running `make qemu-gdb` will make your current shell busy, you cannot call `gdb` in it. You need to open a new shell inside the `build` folder and do a:
 ```bash
-cgdb -q -iex 'add-auto-load-safe-path .'
+gdb --quiet --command=gdb.run
+```
+or
+```bash
+cgdb --quiet --command=gdb.run
 ```
 
-Now you will have:
-1. the QEMU window waiting for you,
-2. the shell where you ran `make qemu-gdb` also waiting for you,
-3. the debugger that loaded a series of symbol files and the location of their `.text` section.
+Now you should have in front of you:
+ 1. the QEMU window waiting for you;
+ 2. the **first** shell where you ran `make qemu-gdb`, which is also waiting for you;
+ 3. the **second** shell where `gdb` is runnign and, you guessed it, is waiting for you.
 
-By default I placed a breakpoint at the begginning of 1) the bootloader, 2) the `kmain` function of the kernel.
+By default I placed a breakpoint at the begginning of (1) the *bootloader* and (2) the *kernel* itself.
 
 So, when gdb starts you need to first give a continue:
 ```bash
 (gdb) continue
 ```
 
-This will make the kernel run, and stop at the first breakpoint which is inside the *bootloader*:
+This will make the kernel run, and stop at the **first** breakpoint which is inside the *bootloader*:
 ```bash
 Breakpoint 1, boot_main (...) at .../mentos/src/boot.c:220
 220     {
@@ -298,13 +427,18 @@ Breakpoint 1, boot_main (...) at .../mentos/src/boot.c:220
 
 giving a second `continue` will get you to the start of the operating system:
 
-This will make the kernel run, and stop at the first breakpoint which is inside the *bootloader*:
+This will make the kernel run, and stop at the **second** breakpoint which is inside the *kernel*:
 ```bash
 Breakpoint 2, kmain (...) at .../mentos/src/kernel.c:95
 95      {
 ```
 
-## 9. Contributors
+There is also a launch configuration for vscode in `.vscode/launch.json`, called `(gdb) Attach`, which should allow you
+to connect to the running process.
+
+*[Back to the Table of Contents](#table-of-contents)*
+
+## Contributors
 
 Project Manager:
 
@@ -326,3 +460,9 @@ Developers:
     - Soft IRQs
     - Timer
     - Signals
+* And many other valuable contributors
+  * [rouseabout](https://github.com/rouseabout)
+  * [seekbytes](https://github.com/seekbytes)
+  * [fischerling](https://github.com/fischerling)
+
+*[Back to the Table of Contents](#table-of-contents)*

doc/CMakeLists.txt

@@ -0,0 +1,299 @@
+# Find Doxygen
+find_package(Doxygen)
+
+if (DOXYGEN_FOUND)
+    # Read the file with the version.
+    file(READ ${PROJECT_SOURCE_DIR}/mentos/inc/version.h version_file)
+    # Extract the OS version.
+    string(REGEX MATCH "OS_MAJOR_VERSION ([0-9]*)" _ ${version_file})
+    set(OS_MAJOR_VERSION ${CMAKE_MATCH_1})
+    string(REGEX MATCH "OS_MINOR_VERSION ([0-9]*)" _ ${version_file})
+    set(OS_MINOR_VERSION ${CMAKE_MATCH_1})
+    string(REGEX MATCH "OS_MICRO_VERSION ([0-9]*)" _ ${version_file})
+    set(OS_MICRO_VERSION ${CMAKE_MATCH_1})
+    # Setup the Doxygen documentation.
+    set(DOXYGEN_PROJECT_NAME "MentOS")
+    set(DOXYGEN_PROJECT_NUMBER "${OS_MAJOR_VERSION}.${OS_MINOR_VERSION}.${OS_MICRO_VERSION}")
+    set(DOXYGEN_PROJECT_BRIEF "The Mentoring Operating System")
+    set(DOXYGEN_USE_MDFILE_AS_MAINPAGE ${PROJECT_SOURCE_DIR}/README.md)
+    set(DOXYGEN_IMAGE_PATH ${PROJECT_SOURCE_DIR}/doc/resources)
+    set(DOXYGEN_SHOW_INCLUDE_FILES NO)
+    set(DOXYGEN_GENERATE_TREEVIEW NO)
+    set(DOXYGEN_WARN_NO_PARAMDOC YES)
+
+    set(DOXYGEN_ENABLE_PREPROCESSING YES)
+    set(DOXYGEN_EXTRACT_STATIC YES)
+    set(DOXYGEN_MACRO_EXPANSION YES)
+    set(DOXYGEN_EXPAND_ONLY_PREDEF YES)
+    set(DOXYGEN_PREDEFINED "__attribute__((x))= _syscall0= _syscall0(x)= _syscall1(x)= _syscall2(x)= _syscall3(x)=")
+
+    set(DOXYGEN_WARN_FORMAT "$file($line): $text")
+    set(DOXYGEN_HTML_STYLESHEET ${PROJECT_SOURCE_DIR}/doc/doxygen.css)
+    doxygen_add_docs(
+        ${PROJECT_NAME}_documentation
+        ${PROJECT_SOURCE_DIR}/README.md
+        ${PROJECT_SOURCE_DIR}/LICENSE.md
+        ${PROJECT_SOURCE_DIR}/doc/signal.md
+        ${PROJECT_SOURCE_DIR}/doc/syscall.md
+        
+        ${PROJECT_SOURCE_DIR}/mentos/inc/boot.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/descriptor_tables/gdt.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/descriptor_tables/idt.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/descriptor_tables/isr.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/descriptor_tables/tss.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/devices/fpu.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/devices/pci.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/ata/ata.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/ata/ata_types.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/fdc.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/keyboard/keyboard.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/keyboard/keymap.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/mouse.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/ps2.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/drivers/rtc.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/elf/elf.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/fs/ext2.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/fs/ioctl.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/fs/procfs.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/fs/vfs.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/fs/vfs_types.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/hardware/cpuid.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/hardware/pic8259.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/hardware/timer.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/io/proc_modules.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/io/vga/vga.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/io/vga/vga_font.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/io/vga/vga_mode.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/io/vga/vga_palette.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/io/video.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/kernel.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/compiler.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/hashmap.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/irqflags.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/list.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/list_head.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/mutex.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/ndtree.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/rbtree.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/spinlock.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/stack_helper.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/klib/stdatomic.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/link_access.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/buddysystem.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/gfp.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/kheap.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/paging.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/slab.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/vmem_map.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/mem/zone_allocator.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/multiboot.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/process/prio.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/process/process.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/process/scheduler.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/process/wait.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/proc_access.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/sys/errno.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/sys/ipc.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/sys/module.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/sys/reboot.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/sys/types.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/sys/utsname.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/system/panic.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/system/printk.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/system/signal.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/system/syscall.h
+        ${PROJECT_SOURCE_DIR}/mentos/inc/version.h
+
+        ${PROJECT_SOURCE_DIR}/mentos/src/boot.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/exception.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/gdt.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/idt.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/interrupt.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/tss.c
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+        ${PROJECT_SOURCE_DIR}/mentos/src/devices/pci.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/ata.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/fdc.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/keyboard/keyboard.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/keyboard/keymap.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/mouse.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/ps2.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/drivers/rtc.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/elf/elf.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/ext2.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/ioctl.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/namei.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/open.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/procfs.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/readdir.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/read_write.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/stat.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/fs/vfs.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/hardware/cpuid.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/hardware/pic8259.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/hardware/timer.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/debug.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/mm_io.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_running.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_system.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_video.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/stdio.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/vga/vga.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/io/video.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/ipc/msg.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/ipc/sem.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/ipc/shm.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/kernel/sys.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/kernel.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/assert.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/ctype.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/fcvt.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/hashmap.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/libgen.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/list.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/math.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/mutex.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/ndtree.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/rbtree.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/spinlock.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/strerror.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/string.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/time.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/vscanf.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/klib/vsprintf.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/mem/buddysystem.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/mem/kheap.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/mem/paging.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/mem/slab.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/mem/vmem_map.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/mem/zone_allocator.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/multiboot.c
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+        ${PROJECT_SOURCE_DIR}/mentos/src/process/scheduler.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/process/scheduler_algorithm.c
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+        ${PROJECT_SOURCE_DIR}/mentos/src/system/panic.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/system/printk.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/system/signal.c
+        ${PROJECT_SOURCE_DIR}/mentos/src/system/syscall.c
+
+        ${PROJECT_SOURCE_DIR}/mentos/src/boot.S
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/exception.S
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/gdt.S
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/idt.S
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/interrupt.S
+        ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/tss.S
+        ${PROJECT_SOURCE_DIR}/mentos/src/process/user.S
+
+        ${PROJECT_SOURCE_DIR}/libc/inc/array.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/assert.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/bits/ioctls.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/bits/stat.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/bits/termios-struct.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/ctype.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/fcntl.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/fcvt.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/grp.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/io/ansi_colors.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/io/debug.h
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+        ${PROJECT_SOURCE_DIR}/libc/inc/io/port_io.h
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+        ${PROJECT_SOURCE_DIR}/libc/inc/limits.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/math.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/pwd.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/ring_buffer.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/sched.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/signal.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/stdarg.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/stdbool.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/stddef.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/stdint.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/stdio.h
+        ${PROJECT_SOURCE_DIR}/libc/inc/stdlib.h
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+
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+        ${PROJECT_SOURCE_DIR}/libc/src/setenv.c
+        ${PROJECT_SOURCE_DIR}/libc/src/stdio.c
+        ${PROJECT_SOURCE_DIR}/libc/src/stdlib.c
+        ${PROJECT_SOURCE_DIR}/libc/src/strerror.c
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+        ${PROJECT_SOURCE_DIR}/libc/src/sys/ioctl.c
+        ${PROJECT_SOURCE_DIR}/libc/src/sys/unistd.c
+        ${PROJECT_SOURCE_DIR}/libc/src/sys/utsname.c
+        ${PROJECT_SOURCE_DIR}/libc/src/termios.c
+        ${PROJECT_SOURCE_DIR}/libc/src/time.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/chdir.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/close.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/creat.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/exec.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/exit.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/fork.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getcwd.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getdents.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getgid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getpgid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getpid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getppid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getsid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/getuid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/interval.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/kill.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/lseek.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/mkdir.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/nice.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/open.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/read.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/reboot.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/rmdir.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/setgid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/setpgid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/setsid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/setuid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/signal.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/stat.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/unlink.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/waitpid.c
+        ${PROJECT_SOURCE_DIR}/libc/src/unistd/write.c
+        ${PROJECT_SOURCE_DIR}/libc/src/vscanf.c
+        ${PROJECT_SOURCE_DIR}/libc/src/vsprintf.c
+
+        ${PROJECT_SOURCE_DIR}/libc/src/crt0.S
+    )
+endif (DOXYGEN_FOUND)

doc/doxygen.css

@@ -26,6 +26,31 @@
   outline: none;
 }
 
+.sm-dox a:hover {
+  color: #4b5263;
+  background-color: #A9B7C6;
+}
+
+.sm-dox ul,
+.sm-dox ul a {
+  color: #A9B7C6;
+  background-color: #4b5263;
+}
+
+.sm-dox ul a.highlighted {
+  color: #4b5263;
+  background-color: #A9B7C6;
+}
+
+.sm-dox ul a:hover {
+  color: #4b5263;
+  background-color: #A9B7C6;
+  background-image: none;
+  background-repeat: no-repeat;
+  text-shadow: none;
+  outline: none;
+}
+
 .memberdecls tr:not(:first-child) {
   background-color: #333842;
 }
@@ -599,7 +624,8 @@ table.memberdecls {
 }
 
 .memTemplParams {
-  color: #4665A2;
+  color: #728dc2;
+  font-weight: bold;
   white-space: nowrap;
   font-size: 80%;
 }
@@ -633,9 +659,10 @@ table.memberdecls {
 
 .memtemplate {
   font-size: 80%;
-  color: #4665A2;
-  font-weight: normal;
+  color: #728dc2;
+  font-weight: bold;
   margin-left: 9px;
+  white-space: nowrap;
 }
 
 .memnav {
@@ -686,6 +713,12 @@ dl.reflist dd {
   padding: 1em;
 }
 
+.memdoc p {
+  padding: 0.25em;
+  border-radius: 4px;
+  background-color: #3A3F49;
+}
+
 dl.reflist dt {
   padding: 5px;
 }
@@ -857,6 +890,7 @@ div.directory {
   font-family: Arial, Helvetica;
   font-weight: bold;
   font-size: 12px;
+  line-height: 16px;
   height: 16px;
   width: 16px;
   display: inline-block;
@@ -879,7 +913,7 @@ div.directory {
   height: 18px;
   margin-bottom: 4px;
   background-image: url("folderopen.png");
-  background-position: 0px -4px;
+  /* background-position: 0px -4px; */
   background-repeat: repeat-y;
   vertical-align: top;
   display: inline-block;
@@ -890,7 +924,7 @@ div.directory {
   height: 18px;
   margin-bottom: 4px;
   background-image: url("folderclosed.png");
-  background-position: 0px -4px;
+  /* background-position: 0px -4px; */
   background-repeat: repeat-y;
   vertical-align: top;
   display: inline-block;
@@ -901,7 +935,7 @@ div.directory {
   height: 18px;
   margin-bottom: 4px;
   background-image: url("doc.png");
-  background-position: 0px -4px;
+  /* background-position: 0px -4px; */
   background-repeat: repeat-y;
   vertical-align: top;
   display: inline-block;
@@ -950,7 +984,7 @@ table.doxtable th {
 }
 
 table.fieldtable {
-  /*width: 100%;*/
+  width: fit-content;
   margin-bottom: 10px;
   border: 1px solid #A8B8D9;
   border-spacing: 0px;
@@ -960,7 +994,6 @@ table.fieldtable {
   -moz-box-shadow: rgba(0, 0, 0, 0.15) 2px 2px 2px;
   -webkit-box-shadow: 2px 2px 2px rgba(0, 0, 0, 0.15);
   box-shadow: 2px 2px 2px rgba(0, 0, 0, 0.15);
-  width: fit-content;
 }
 
 .fieldtable td,
@@ -998,11 +1031,9 @@ table.fieldtable {
 }
 
 .fieldtable th {
-  background-image: url("nav_f.png");
-  background-repeat: repeat-x;
-  background-color: #E2E8F2;
-  font-size: 90%;
-  color: #253555;
+  font-size: 100%;
+  color: #d7dee4;
+  background-color: #49515f;
   padding-bottom: 4px;
   padding-top: 5px;
   text-align: left;

doc/doxygen/CMakeLists.txt

@@ -1,37 +0,0 @@
-# Find Doxygen
-find_package(Doxygen)
-
-if (DOXYGEN_FOUND)
-    set(DOXYGEN_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR})
-    set(DOXYGEN_INDEX_FILE ${DOXYGEN_OUTPUT_DIR}/html/index.html)
-
-    # Replace variables inside @@ with the current values.
-    set(DOXYFILE_IN  ${CMAKE_CURRENT_SOURCE_DIR}/Doxyfile)
-    set(DOXYFILE_OUT ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile)
-    configure_file(${DOXYFILE_IN} ${DOXYFILE_OUT} @ONLY)
-
-    # Copy the files needd by the documentation.
-    set(DOXYFILE_CSS    ${CMAKE_CURRENT_SOURCE_DIR}/doxygen.css)
-    set(DOXYFILE_HEADER ${CMAKE_CURRENT_SOURCE_DIR}/header.html)
-    set(DOXYFILE_FOOTER ${CMAKE_CURRENT_SOURCE_DIR}/footer.html)
-
-    # Doxygen won't create this for us.
-    file(MAKE_DIRECTORY ${DOXYGEN_OUTPUT_DIR})
-
-    add_custom_command(
-        OUTPUT ${DOXYGEN_INDEX_FILE}
-        COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE_OUT}
-
-        MAIN_DEPENDENCY ${DOXYFILE_OUT} ${DOXYFILE_IN}
-        COMMENT "Generating docs"
-    )
-    add_custom_target(
-        doxygen_doc
-        DEPENDS
-        ${DOXYGEN_INDEX_FILE}
-        ${DOXYFILE_IN}
-        ${DOXYFILE_CSS}
-        ${DOXYFILE_HEADER}
-        ${DOXYFILE_FOOTER}
-    )
-endif (DOXYGEN_FOUND)

doc/doxygen/footer.html

@@ -1,40 +0,0 @@
-        <!-- HTML footer for doxygen 1.8.16-->
-        <!-- start footer part -->
-        <!--BEGIN GENERATE_TREEVIEW-->
-        <div id="nav-path" class="navpath">
-            <!-- id is needed for treeview function! -->
-            <ul>
-                $navpath
-                <li class="footer">$generatedby
-                    <a href="http://www.doxygen.org/index.html">
-                        <img class="footer" src="$relpath^doxygen.png" alt="doxygen" />
-                    </a> $doxygenversion
-                </li>
-            </ul>
-        </div>
-        <!--END GENERATE_TREEVIEW-->
-        <!--BEGIN !GENERATE_TREEVIEW-->
-        <div class="footer">
-            <hr class="footer" />
-            <ul class="footer-info">
-                <li class="footer-info-lastmode">
-                    This page was last modified on $datetime.
-                </li>
-                <li class="footer-info-copyright">
-                    MentOs © 2014–2022 the MentOs-Team, and numerous contributors.<br>
-                    It is available for use and modification under the&#160;
-                    <a href="$relpath^md_LICENSE.html">MIT License</a>.<br>
-                </li>
-            </ul>
-            <hr class="footer" />
-            <address class="footer">
-                $generatedby&#160;
-                <a href="http://www.doxygen.org/index.html">
-                    <img class="footer" src="$relpath^doxygen.png" alt="doxygen" />
-                </a> $doxygenversion
-            </address>
-        </div>
-    <!--END !GENERATE_TREEVIEW-->
-    </body>
-
-</html>

doc/doxygen/header.html

@@ -1,66 +0,0 @@
-<!-- HTML header for doxygen 1.8.17-->
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
-
-<head>
-    <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8" />
-    <meta http-equiv="X-UA-Compatible" content="IE=9" />
-    <meta name="generator" content="Doxygen $doxygenversion" />
-    <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <!--BEGIN PROJECT_NAME-->
-    <title>$projectname: $title</title>
-    <!--END PROJECT_NAME-->
-    <!--BEGIN !PROJECT_NAME-->
-    <title>$title</title>
-    <!--END !PROJECT_NAME-->
-    <link href="$relpath^tabs.css" rel="stylesheet" type="text/css" />
-    <script type="text/javascript" src="$relpath^jquery.js"></script>
-    <script type="text/javascript" src="$relpath^dynsections.js"></script>
-    $treeview
-    $search
-    $mathjax
-    <link href="$relpath^$stylesheet" rel="stylesheet" type="text/css" />
-    $extrastylesheet
-</head>
-
-<body>
-    <div id="top">
-        <!-- do not remove this div, it is closed by doxygen! -->
-
-        <!--BEGIN TITLEAREA-->
-        <div id="titlearea">
-            <table cellspacing="0" cellpadding="0">
-                <tbody>
-                    <tr style="height: 56px;">
-                        <!--BEGIN PROJECT_LOGO-->
-                        <td id="projectlogo"><img alt="Logo" src="$relpath^$projectlogo" /></td>
-                        <!--END PROJECT_LOGO-->
-                        <!--BEGIN PROJECT_NAME-->
-                        <td id="projectalign" style="padding-left: 0.5em;">
-                            <div id="projectname">$projectname
-                                <!--BEGIN PROJECT_NUMBER-->&#160;<span id="projectnumber">$projectnumber</span>
-                                <!--END PROJECT_NUMBER-->
-                            </div>
-                            <!--BEGIN PROJECT_BRIEF-->
-                            <div id="projectbrief">$projectbrief</div>
-                            <!--END PROJECT_BRIEF-->
-                        </td>
-                        <!--END PROJECT_NAME-->
-                        <!--BEGIN !PROJECT_NAME-->
-                        <!--BEGIN PROJECT_BRIEF-->
-                        <td style="padding-left: 0.5em;">
-                            <div id="projectbrief">$projectbrief</div>
-                        </td>
-                        <!--END PROJECT_BRIEF-->
-                        <!--END !PROJECT_NAME-->
-                        <!--BEGIN DISABLE_INDEX-->
-                        <!--BEGIN SEARCHENGINE-->
-                        <td>$searchbox</td>
-                        <!--END SEARCHENGINE-->
-                        <!--END DISABLE_INDEX-->
-                    </tr>
-                </tbody>
-            </table>
-        </div>
-        <!--END TITLEAREA-->
-        <!-- end header part -->

doc/syscall.md

@@ -7,6 +7,7 @@ specifically:
 
 1. Implemented
 2. Tested
+X. Obsolete
 
 If the column is empty it means that it's not implemented yet.
 
@@ -22,7 +23,7 @@ If the column is empty it means that it's not implemented yet.
  2 | 5   | sys_open                   | fs/open.c                   | const char *             | int                          | int                     | -               | -                |
  2 | 6   | sys_close                  | fs/open.c                   | int                      | -                            | -                       | -               | -                |
  2 | 7   | sys_waitpid                | kernel/exit.c               | pid_t                    | unsigned int *               | int                     | -               | -                |
-   | 8   | sys_creat                  | fs/open.c                   | const char *             | int                          | -                       | -               | -                |
+ 2 | 8   | sys_creat                  | fs/open.c                   | const char *             | int                          | -                       | -               | -                |
    | 9   | sys_link                   | fs/namei.c                  | const char *             | const char *                 | -                       | -               | -                |
  2 | 10  | sys_unlink                 | fs/namei.c                  | const char *             | -                            | -                       | -               | -                |
  2 | 11  | sys_execve                 | arch/i386/kernel/process.c  | struct pt_regs           | -                            | -                       | -               | -                |
@@ -36,11 +37,11 @@ If the column is empty it means that it's not implemented yet.
  2 | 20  | sys_getpid                 | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
    | 21  | sys_mount                  | fs/super.c                  | char *                   | char *                       | char *                  | -               | -                |
    | 22  | sys_oldumount              | fs/super.c                  | char *                   | -                            | -                       | -               | -                |
-   | 23  | sys_setuid                 | kernel/sys.c                | uid_t                    | -                            | -                       | -               | -                |
-   | 24  | sys_getuid                 | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
+ 2 | 23  | sys_setuid                 | kernel/sys.c                | uid_t                    | -                            | -                       | -               | -                |
+ 2 | 24  | sys_getuid                 | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
    | 25  | sys_stime                  | kernel/time.c               | int *                    | -                            | -                       | -               | -                |
    | 26  | sys_ptrace                 | arch/i386/kernel/ptrace.c   | long                     | long                         | long                    | long            | -                |
-   | 27  | sys_alarm                  | kernel/sched.c              | unsigned int             | -                            | -                       | -               | -                |
+ 2 | 27  | sys_alarm                  | kernel/sched.c              | unsigned int             | -                            | -                       | -               | -                |
  2 | 28  | sys_fstat                  | fs/stat.c                   | unsigned int             | struct __old_kernel_stat *   | -                       | -               | -                |
    | 29  | sys_pause                  | arch/i386/kernel/sys_i386.c | -                        | -                            | -                       | -               | -                |
    | 30  | sys_utime                  | fs/open.c                   | char *                   | struct utimbuf *             | -                       | -               | -                |
@@ -55,8 +56,8 @@ If the column is empty it means that it's not implemented yet.
    | 42  | sys_pipe                   | arch/i386/kernel/sys_i386.c | unsigned long *          | -                            | -                       | -               | -                |
    | 43  | sys_times                  | kernel/sys.c                | struct tms *             | -                            | -                       | -               | -                |
  2 | 45  | sys_brk                    | mm/mmap.c                   | unsigned long            | -                            | -                       | -               | -                |
-   | 46  | sys_setgid                 | kernel/sys.c                | gid_t                    | -                            | -                       | -               | -                |
-   | 47  | sys_getgid                 | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
+ 2 | 46  | sys_setgid                 | kernel/sys.c                | gid_t                    | -                            | -                       | -               | -                |
+ 2 | 47  | sys_getgid                 | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
  1 | 48  | sys_signal                 | kernel/signal.c             | int                      | __sighandler_t               | -                       | -               | -                |
    | 49  | sys_geteuid                | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
    | 50  | sys_getegid                | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
@@ -64,7 +65,7 @@ If the column is empty it means that it's not implemented yet.
    | 52  | sys_umount                 | fs/super.c                  | char *                   | int                          | -                       | -               | -                |
  1 | 54  | sys_ioctl                  | fs/ioctl.c                  | unsigned int             | unsigned int                 | unsigned long           | -               | -                |
    | 55  | sys_fcntl                  | fs/fcntl.c                  | unsigned int             | unsigned int                 | unsigned long           | -               | -                |
-   | 57  | sys_setpgid                | kernel/sys.c                | pid_t                    | pid_t                        | -                       | -               | -                |
+ 2 | 57  | sys_setpgid                | kernel/sys.c                | pid_t                    | pid_t                        | -                       | -               | -                |
    | 59  | sys_olduname               | arch/i386/kernel/sys_i386.c | struct oldold_utsname *  | -                            | -                       | -               | -                |
    | 60  | sys_umask                  | kernel/sys.c                | int                      | -                            | -                       | -               | -                |
    | 61  | sys_chroot                 | fs/open.c                   | const char *             | -                            | -                       | -               | -                |
@@ -72,10 +73,10 @@ If the column is empty it means that it's not implemented yet.
    | 63  | sys_dup2                   | fs/fcntl.c                  | unsigned int             | unsigned int                 | -                       | -               | -                |
  2 | 64  | sys_getppid                | kernel/sched.c              | -                        | -                            | -                       | -               | -                |
    | 65  | sys_getpgrp                | kernel/sys.c                | -                        | -                            | -                       | -               | -                |
-   | 66  | sys_setsid                 | kernel/sys.c                | -                        | -                            | -                       | -               | -                |
+ 2 | 66  | sys_setsid                 | kernel/sys.c                | -                        | -                            | -                       | -               | -                |
  1 | 67  | sys_sigaction              | arch/i386/kernel/signal.c   | int                      | const struct old_sigaction * | struct old_sigaction *  | -               | -                |
-   | 68  | sys_sgetmask               | kernel/signal.c             | -                        | -                            | -                       | -               | -                |
-   | 69  | sys_ssetmask               | kernel/signal.c             | int                      | -                            | -                       | -               | -                |
+ X | 68  | sys_sgetmask               | kernel/signal.c             | -                        | -                            | -                       | -               | -                |
+ X | 69  | sys_ssetmask               | kernel/signal.c             | int                      | -                            | -                       | -               | -                |
    | 70  | sys_setreuid               | kernel/sys.c                | uid_t                    | uid_t                        | -                       | -               | -                |
    | 71  | sys_setregid               | kernel/sys.c                | gid_t                    | gid_t                        | -                       | -               | -                |
    | 72  | sys_sigsuspend             | arch/i386/kernel/signal.c   | int                      | int                          | old_sigset_t            | -               | -                |

files/home/user/README

@@ -0,0 +1 @@
+../../README

files/usr/share/man/cat.man

@@ -0,0 +1,8 @@
+SYNOPSIS
+    cat [FILE]
+
+DESCRIPTION
+    Prints the content of the given file.
+
+OPTIONS
+    -h --help : shows command help.

files/usr/share/man/clear.man

@@ -0,0 +1,5 @@
+SYNOPSIS
+    clear
+
+DESCRIPTION
+    Clears the screen.

files/usr/share/man/cpuid.man

@@ -0,0 +1,5 @@
+SYNOPSIS
+    cpuid
+
+DESCRIPTION
+    Not currently implemented.

files/usr/share/man/date.man

@@ -0,0 +1,5 @@
+SYNOPSIS
+    date
+
+DESCRIPTION
+    Shows the current date.

files/usr/share/man/echo.man

@@ -0,0 +1,6 @@
+SYNOPSIS
+    echo [STRING]
+
+DESCRIPTION
+    Displays a line of text.
+    

files/usr/share/man/ipcs.man

@@ -0,0 +1,5 @@
+SYNOPSIS
+	ipcs [options]
+
+DESCRIPTION
+	Ipcs shows information on System V inter-process communication facilities.

files/usr/share/man/ls.man

@@ -1,6 +1,3 @@
-NAME
-    ls - list directory contents
-
 SYNOPSIS
     ls [OPTIONS] [FILE/FOLDER]
 
@@ -10,5 +7,6 @@ DESCRIPTION
     inside the current folder.
     
 OPTIONS
-    -a  : list all entries.
-    -l  : show the entries as a detailed list.
+    -h --help : shows command help.
+    -a --all  : list all entries.
+    -l --long : show the entries as a detailed long list.

files/usr/share/man/start.man

@@ -0,0 +1,12 @@
+SYNOPSIS
+    start [OPTIONS] [FILE]
+
+DESCRIPTION
+    Start a recording session aimed at displaying an ordered list of 50 items 
+    containing information about the processes that the CPU has just processed.
+
+
+OPTIONS
+    -h: shows command help. //non funziona per ora lol
+    -p: start the session with generated children
+    -f [FILE]: start the session launching a specified program

iso/boot/grub/grub.cfg

@@ -1,4 +1,4 @@
-set timeout=1
+set timeout=5
 set default=0
 
 menuentry "MentOS" {

libc/CMakeLists.txt

@@ -1,148 +1,70 @@
-# =============================================================================
-# Author: Enrico Fraccaroli
-# =============================================================================
-# Set the minimum required version of cmake.
-cmake_minimum_required(VERSION 3.1...3.22)
-# Initialize the project.
-project(libc C ASM)
-
-# =============================================================================
-# ASSEMBLY
-# =============================================================================
-
-# Enable the assembly language.
-enable_language(ASM)
-# Find the NASM compiler.
-find_program(ASM_COMPILER NAMES nasm HINTS /usr/bin/ /usr/local/bin/)
-# Mark the variable ASM_COMPILER as advanced.
-mark_as_advanced(ASM_COMPILER)
-# Check that we have found the compiler.
-if(NOT ASM_COMPILER)
-    message(FATAL_ERROR "ASM compiler not found!")
-endif(NOT ASM_COMPILER)
-# Set the asm compiler.
-set(CMAKE_ASM_COMPILER ${ASM_COMPILER})
-# Set the assembly compiler flags.
-set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -f elf")
-set(CMAKE_ASM_COMPILE_OBJECT "<CMAKE_ASM_COMPILER> <FLAGS> -o <OBJECT> <SOURCE>")
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -g")
-    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -O0")
-    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -F dwarf")
-elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
-    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -g")
-    set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -O3")
-endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-
-# =============================================================================
-# C WARNINGs
-# =============================================================================
-
-# Warning flags.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
-
-# Disable some specific warnings.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-but-set-variable")
-
-# Set the compiler options.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
-endif()
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
-elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
-endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-
-# =============================================================================
-# Add the library.
-add_library(
-    ${PROJECT_NAME}
-
-    ${PROJECT_SOURCE_DIR}/src/stdio.c
-    ${PROJECT_SOURCE_DIR}/src/ctype.c
-    ${PROJECT_SOURCE_DIR}/src/string.c
-    ${PROJECT_SOURCE_DIR}/src/stdlib.c
-    ${PROJECT_SOURCE_DIR}/src/math.c
-    ${PROJECT_SOURCE_DIR}/src/fcvt.c
-    ${PROJECT_SOURCE_DIR}/src/time.c
-    ${PROJECT_SOURCE_DIR}/src/strerror.c
-    ${PROJECT_SOURCE_DIR}/src/termios.c
-    ${PROJECT_SOURCE_DIR}/src/libgen.c
-    ${PROJECT_SOURCE_DIR}/src/vsprintf.c
-    ${PROJECT_SOURCE_DIR}/src/vscanf.c
-    ${PROJECT_SOURCE_DIR}/src/pwd.c
-    ${PROJECT_SOURCE_DIR}/src/grp.c
-    ${PROJECT_SOURCE_DIR}/src/sched.c
-    ${PROJECT_SOURCE_DIR}/src/setenv.c
-    ${PROJECT_SOURCE_DIR}/src/assert.c
-    ${PROJECT_SOURCE_DIR}/src/abort.c
-    ${PROJECT_SOURCE_DIR}/src/io/mm_io.c
-    ${PROJECT_SOURCE_DIR}/src/io/port_io.c
-    ${PROJECT_SOURCE_DIR}/src/ipc/ipc.c
-    ${PROJECT_SOURCE_DIR}/src/sys/unistd.c
-    ${PROJECT_SOURCE_DIR}/src/sys/errno.c
-    ${PROJECT_SOURCE_DIR}/src/sys/utsname.c
-    ${PROJECT_SOURCE_DIR}/src/sys/ioctl.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/creat.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getppid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getpid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/exit.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setsid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getsid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setpgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getpgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setuid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getuid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/fork.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/read.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/write.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/exec.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/nice.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/open.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/reboot.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/waitpid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/chdir.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getcwd.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/close.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/stat.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/rmdir.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/mkdir.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/unlink.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getdents.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/lseek.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/kill.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/signal.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/interval.c
-    ${PROJECT_SOURCE_DIR}/src/libc_start.c
-    ${PROJECT_SOURCE_DIR}/src/debug.c
-    ${PROJECT_SOURCE_DIR}/src/crt0.S
+# Add the libc library.
+add_library(libc
+    ${PROJECT_SOURCE_DIR}/libc/src/stdio.c
+    ${PROJECT_SOURCE_DIR}/libc/src/ctype.c
+    ${PROJECT_SOURCE_DIR}/libc/src/string.c
+    ${PROJECT_SOURCE_DIR}/libc/src/stdlib.c
+    ${PROJECT_SOURCE_DIR}/libc/src/math.c
+    ${PROJECT_SOURCE_DIR}/libc/src/fcvt.c
+    ${PROJECT_SOURCE_DIR}/libc/src/time.c
+    ${PROJECT_SOURCE_DIR}/libc/src/strerror.c
+    ${PROJECT_SOURCE_DIR}/libc/src/termios.c
+    ${PROJECT_SOURCE_DIR}/libc/src/libgen.c
+    ${PROJECT_SOURCE_DIR}/libc/src/vsprintf.c
+    ${PROJECT_SOURCE_DIR}/libc/src/vscanf.c
+    ${PROJECT_SOURCE_DIR}/libc/src/pwd.c
+    ${PROJECT_SOURCE_DIR}/libc/src/grp.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sched.c
+    ${PROJECT_SOURCE_DIR}/libc/src/readline.c
+    ${PROJECT_SOURCE_DIR}/libc/src/setenv.c
+    ${PROJECT_SOURCE_DIR}/libc/src/assert.c
+    ${PROJECT_SOURCE_DIR}/libc/src/abort.c
+    ${PROJECT_SOURCE_DIR}/libc/src/io/mm_io.c
+    ${PROJECT_SOURCE_DIR}/libc/src/io/debug.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/ipc.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/unistd.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/errno.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/utsname.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/mman.c
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/ioctl.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/creat.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getppid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getpid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/exit.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setsid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getsid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setpgid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getpgid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setgid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getgid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setuid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getuid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/fork.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/read.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/write.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/exec.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/nice.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/open.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/reboot.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/waitpid.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/chdir.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getcwd.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/close.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/stat.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/rmdir.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/mkdir.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/unlink.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getdents.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/lseek.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/kill.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/signal.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/interval.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/symlink.c
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/readlink.c
+    ${PROJECT_SOURCE_DIR}/libc/src/libc_start.c
+    ${PROJECT_SOURCE_DIR}/libc/src/crt0.s
 )
-
 # Add the includes.
-target_include_directories(${PROJECT_NAME} PUBLIC inc)
-
+target_include_directories(libc PRIVATE ${PROJECT_SOURCE_DIR}/libc/inc)
 # Remove the 'lib' prefix.
-set_target_properties(${PROJECT_NAME} PROPERTIES PREFIX "")
+set_target_properties(libc PROPERTIES PREFIX "")

libc/inc/array.h

@@ -1,6 +1,6 @@
 /// @file array.h
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -34,5 +34,5 @@
         ARRAY_FREE(arr->buffer);                                                      \
     }
 
-#undef ARRAY_ALLOC malloc
-#undef ARRAY_FREE free
+#undef ARRAY_ALLOC
+#undef ARRAY_FREE

libc/inc/assert.h

@@ -1,6 +1,6 @@
 /// @file assert.h
 /// @brief Defines the function and pre-processor macro for assertions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/bits/ioctls.h

@@ -1,6 +1,6 @@
 /// @file ioctls.h
 /// @brief Input/Output ConTroL (IOCTL) numbers.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/bits/stat.h

@@ -1,6 +1,6 @@
 /// @file stat.h
 /// @brief Defines the structure used by the functiosn fstat(), lstat(), and stat().
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/bits/termios-struct.h

@@ -1,6 +1,6 @@
 /// @file termios-struct.h
 /// @brief Definition of the `termios` structure.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -43,4 +43,4 @@ typedef struct termios {
 #define IEXTEN  0x00000400 ///< Enables implementation-defined input processing.
 
 /// @brief Mask for extracting control values.
-#define CTRL(x) (x & 037)
+#define CTRL(x) ((x) & 037)

libc/inc/ctype.h

@@ -1,6 +1,6 @@
 /// @file ctype.h
 /// @brief Functions related to character handling.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/debug.h

@@ -1,44 +0,0 @@
-/// @file debug.h
-/// @brief Debugging primitives.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
-/// See LICENSE.md for details.
-
-#pragma once
-
-#ifndef __DEBUG_HEADER__
-/// Header for identifying outputs coming from a mechanism.
-#define __DEBUG_HEADER__
-#endif
-
-/// @brief Extract the filename from the full path provided by __FILE__.
-#define __FILENAME__ (__builtin_strrchr(__FILE__, '/') ? __builtin_strrchr(__FILE__, '/') + 1 : __FILE__)
-
-/// @brief Prints the given character to debug output.
-/// @param c The character to print.
-void dbg_putchar(char c);
-
-/// @brief Prints the given string to debug output.
-/// @param s The string to print.
-void dbg_puts(const char *s);
-
-/// @brief Prints the given string to the debug output.
-/// @param file   The name of the file.
-/// @param fun    The name of the function.
-/// @param line   The line inside the file.
-/// @param format The format to used, see printf.
-/// @param ...    The list of arguments.
-void dbg_printf(const char *file, const char *fun, int line, const char *format, ...);
-
-/// @brief Transforms the given amount of bytes to a readable string.
-/// @param bytes The bytes to turn to string.
-/// @return String representing the bytes in human readable form.
-const char *to_human_size(unsigned long bytes);
-
-/// @brief Transforms the given value to a binary string.
-/// @param value to print.
-/// @param length of the binary output.
-/// @return String representing the binary value.
-const char *dec_to_binary(unsigned long value, unsigned length);
-
-/// Prints a debugging message.
-#define pr_debug(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__ __VA_ARGS__)

libc/inc/fcntl.h

@@ -1,6 +1,6 @@
 /// @file fcntl.h
 /// @brief Headers of functions fcntl() and open().
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -22,18 +22,18 @@
 #define S_ISUID 0x0800 ///< Set user id on execution
 #define S_ISGID 0x0400 ///< Set group id on execution
 #define S_ISVTX 0x0200 ///< Save swapped text even after use (Sticky Bit)
-#define S_IRWXU 0x01C0 ///< rwx------- : User can read/write/execute
-#define S_IRUSR 0x0100 ///< -r-------- : User can read
-#define S_IWUSR 0x0080 ///< --w------- : User can write
-#define S_IXUSR 0x0040 ///< ---x------ : User can execute
-#define S_IRWXG 0x0038 ///< ----rwx--- : Group can read/write/execute
-#define S_IRGRP 0x0020 ///< ----r----- : Group can read
-#define S_IWGRP 0x0010 ///< -----w---- : Group can write
-#define S_IXGRP 0x0008 ///< ------x--- : Group can execute
-#define S_IRWXO 0x0007 ///< -------rwx : Others can read/write/execute
-#define S_IROTH 0x0004 ///< -------r-- : Others can read
-#define S_IWOTH 0x0002 ///< --------w- : Others can write
-#define S_IXOTH 0x0001 ///< ---------x : Others can execute
+#define S_IRWXU 0x01C0 ///< rwx------ : User can read/write/execute
+#define S_IRUSR 0x0100 ///< r-------- : User can read
+#define S_IWUSR 0x0080 ///< -w------- : User can write
+#define S_IXUSR 0x0040 ///< --x------ : User can execute
+#define S_IRWXG 0x0038 ///< ---rwx--- : Group can read/write/execute
+#define S_IRGRP 0x0020 ///< ---r----- : Group can read
+#define S_IWGRP 0x0010 ///< ----w---- : Group can write
+#define S_IXGRP 0x0008 ///< -----x--- : Group can execute
+#define S_IRWXO 0x0007 ///< ------rwx : Others can read/write/execute
+#define S_IROTH 0x0004 ///< ------r-- : Others can read
+#define S_IWOTH 0x0002 ///< -------w- : Others can write
+#define S_IXOTH 0x0001 ///< --------x : Others can execute
 
 #define S_ISDIR(m)  (((m)&0170000) == 0040000) ///< directory.
 #define S_ISCHR(m)  (((m)&0170000) == 0020000) ///< char special

libc/inc/fcvt.h

@@ -1,6 +1,6 @@
 /// @file fcvt.h
 /// @brief Declare the functions required to turn double values into a string.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/grp.h

@@ -1,6 +1,6 @@
 /// @file grp.h
 /// @brief Defines the structures and functions for managing groups.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -69,4 +69,4 @@ group_t *getgrent(void);
 void endgrent(void);
 
 /// @brief May be called to close the group database when processing is complete.
-void setgrent(void);
+void setgrent(void);

libc/inc/io/ansi_colors.h

@@ -1,6 +1,7 @@
 /// @file ansi_colors.h
-/// @author Enrico Fraccaroli (enry.frak@gmail.com)
-/// @brief Macros for ANSI colors.
+/// @brief List of ANSI colors.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
 
 #pragma once
 

libc/inc/io/debug.h

@@ -1,16 +1,14 @@
 /// @file debug.h
 /// @brief Debugging primitives.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
 #include "sys/kernel_levels.h"
 
-struct pt_regs;
-
 #ifndef __DEBUG_LEVEL__
-/// Defines the debug level.
+/// Defines the debug level, by default we set it to notice.
 #define __DEBUG_LEVEL__ LOGLEVEL_NOTICE
 #endif
 
@@ -28,7 +26,7 @@ void set_log_level(int level);
 
 /// @brief Returns the current loglevel.
 /// @return The current loglevel
-int get_log_level();
+int get_log_level(void);
 
 /// @brief Prints the given character to debug output.
 /// @param c The character to print.
@@ -39,17 +37,14 @@ void dbg_putchar(char c);
 void dbg_puts(const char *s);
 
 /// @brief Prints the given string to the debug output.
-/// @param file   The name of the file.
-/// @param fun    The name of the function.
-/// @param line   The line inside the file.
-/// @param header The header to print.
-/// @param format The format to used, see printf.
-/// @param ...    The list of arguments.
-void dbg_printf(const char *file, const char *fun, int line, char *header, const char *format, ...);
-
-/// @brief Prints the registers on debug output.
-/// @param frame Pointer to the register.
-void dbg_print_regs(struct pt_regs *frame);
+/// @param file the name of the file.
+/// @param fun the name of the function.
+/// @param line the line inside the file.
+/// @param header the header to print.
+/// @param log_level the log level.
+/// @param format the format to used, see printf.
+/// @param ... the list of arguments.
+void dbg_printf(const char *file, const char *fun, int line, char *header, short log_level, const char *format, ...);
 
 /// @brief Transforms the given amount of bytes to a readable string.
 /// @param bytes The bytes to turn to string.
@@ -62,53 +57,71 @@ const char *to_human_size(unsigned long bytes);
 /// @return String representing the binary value.
 const char *dec_to_binary(unsigned long value, unsigned length);
 
-/// Prints a KERN_DEFAULT.
-#define pr_default(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_DEFAULT __VA_ARGS__)
-/// Prints a KERN_EMERG.
+/// Prints a default message, which is always shown.
+#define pr_default(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_DEFAULT, __VA_ARGS__)
+
+/// Prints an emergency message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_EMERG
-#define pr_emerg(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_EMERG __VA_ARGS__)
+#define pr_emerg(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_EMERG, __VA_ARGS__)
 #else
 #define pr_emerg(...)
 #endif
-/// Prints a KERN_ALERT.
+
+/// Prints an alert message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_ALERT
-#define pr_alert(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_ALERT __VA_ARGS__)
+#define pr_alert(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_ALERT, __VA_ARGS__)
 #else
 #define pr_alert(...)
 #endif
-/// Prints a KERN_CRIT.
+
+/// Prints a critical message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_CRIT
-#define pr_crit(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_CRIT __VA_ARGS__)
+#define pr_crit(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_CRIT, __VA_ARGS__)
 #else
 #define pr_crit(...)
 #endif
-/// Prints a KERN_ERR.
+
+/// Prints an error message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_ERR
-#define pr_err(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_ERR __VA_ARGS__)
+#define pr_err(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_ERR, __VA_ARGS__)
 #else
 #define pr_err(...)
 #endif
-/// Prints a KERN_WARNING.
+
+/// Prints a warning message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_WARNING
-#define pr_warning(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_WARNING __VA_ARGS__)
+#define pr_warning(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_WARNING, __VA_ARGS__)
 #else
 #define pr_warning(...)
 #endif
-/// Prints a KERN_NOTICE.
+
+/// Prints a notice message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_NOTICE
-#define pr_notice(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_NOTICE __VA_ARGS__)
+#define pr_notice(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_NOTICE, __VA_ARGS__)
 #else
 #define pr_notice(...)
 #endif
-/// Prints a KERN_INFO.
+
+/// Prints a info message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_INFO
-#define pr_info(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_INFO __VA_ARGS__)
+#define pr_info(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_INFO, __VA_ARGS__)
 #else
 #define pr_info(...)
 #endif
-/// Prints a KERN_DEBUG.
+
+/// Prints a debug message.
 #if __DEBUG_LEVEL__ >= LOGLEVEL_DEBUG
-#define pr_debug(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, KERN_DEBUG __VA_ARGS__)
+#define pr_debug(...) dbg_printf(__FILENAME__, __func__, __LINE__, __DEBUG_HEADER__, LOGLEVEL_DEBUG, __VA_ARGS__)
 #else
 #define pr_debug(...)
 #endif
+
+#ifdef __KERNEL__
+
+struct pt_regs;
+
+/// @brief Prints the registers on debug output.
+/// @param frame Pointer to the register.
+void dbg_print_regs(struct pt_regs *frame);
+
+#endif

libc/inc/io/mm_io.h

@@ -1,6 +1,6 @@
 /// @file mm_io.h
 /// @brief Memory Mapped IO functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -8,19 +8,31 @@
 #include "stdint.h"
 
 /// @brief Reads a 8-bit value from the given address.
+/// @param addr the address we want to read from.
+/// @return the value we read.
 uint8_t in_memb(uint32_t addr);
 
 /// @brief Reads a 16-bit value from the given address.
+/// @param addr the address we want to read from.
+/// @return the value we read.
 uint16_t in_mems(uint32_t addr);
 
 /// @brief Reads a 32-bit value from the given address.
+/// @param addr the address we want to read from.
+/// @return the value we read.
 uint32_t in_meml(uint32_t addr);
 
 /// @brief Writes a 8-bit value at the given address.
+/// @param addr the address we want to write to.
+/// @param value the value we want to write.
 void out_memb(uint32_t addr, uint8_t value);
 
 /// @brief Writes a 16-bit value at the given address.
+/// @param addr the address we want to write to.
+/// @param value the value we want to write.
 void out_mems(uint32_t addr, uint16_t value);
 
 /// @brief Writes a 32-bit value at the given address.
+/// @param addr the address we want to write to.
+/// @param value the value we want to write.
 void out_meml(uint32_t addr, uint32_t value);

libc/inc/io/port_io.h

@@ -1,42 +1,150 @@
 /// @file port_io.h
 /// @brief Byte I/O on ports prototypes.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
-#include "stdint.h"
+/// @brief Reads a 8-bit value from the given port.
+/// @param port the port we want to read from.
+/// @return the value we read.
+static inline unsigned char inportb(unsigned short port)
+{
+    unsigned char result;
+    __asm__ __volatile__("inb %%dx, %%al"
+                         : "=a"(result)
+                         : "dN"(port)
+                         : "memory");
+    return result;
+}
 
-/// @brief      Used for reading from the I/O ports.
-/// @param port The input port.
-/// @return     The read value.
-uint8_t inportb(uint16_t port);
+/// @brief Reads a 16-bit value from the given port.
+/// @param port the port we want to read from.
+/// @return the value we read.
+static inline unsigned short inports(unsigned short port)
+{
+    unsigned short result;
+    __asm__ __volatile__("inw %1, %0"
+                         : "=a"(result)
+                         : "dN"(port)
+                         : "memory");
+    return result;
+}
 
-/// @brief      Used for reading 2 bytes from the I/O ports.
-/// @param port The input port.
-/// @return     The read value.
-uint16_t inports(uint16_t port);
+/// @brief Reads a 32-bit value from the given port.
+/// @param port the port we want to read from.
+/// @return the value we read.
+static inline unsigned int inportl(unsigned short port)
+{
+    unsigned int result;
+    __asm__ __volatile__("inl %%dx, %%eax"
+                         : "=a"(result)
+                         : "dN"(port)
+                         : "memory");
+    return result;
+}
 
-void inportsm(uint16_t port, uint8_t *data, unsigned long size);
+/// @brief Writes a 8-bit value at the given port.
+/// @param port the port we want to write to.
+/// @param value the value we want to write.
+static inline void outportb(unsigned short port, unsigned char value)
+{
+    __asm__ __volatile__("outb %%al, %%dx"
+                         :
+                         : "a"(value), "dN"(port)
+                         : "memory");
+}
 
-/// @brief      Used for reading 4 bytes from the I/O ports.
-/// @param port The input port.
-/// @return     The read value.
-uint32_t inportl(uint16_t port);
+/// @brief Writes a 16-bit value at the given port.
+/// @param port the port we want to write to.
+/// @param value the value we want to write.
+static inline void outports(unsigned short port, unsigned short value)
+{
+    __asm__ __volatile__("outw %1, %0"
+                         :
+                         : "dN"(port), "a"(value)
+                         : "memory");
+}
 
-/// @brief      Use this to write to I/O ports to send bytes to devices.
-/// @param port The output port.
-/// @param data The data to write.
-void outportb(uint16_t port, uint8_t data);
+/// @brief Writes a 32-bit value at the given port.
+/// @param port the port we want to write to.
+/// @param value the value we want to write.
+static inline void outportl(unsigned short port, unsigned int value)
+{
+    __asm__ __volatile__("outl %%eax, %%dx"
+                         :
+                         : "dN"(port), "a"(value)
+                         : "memory");
+}
 
-/// @brief      Use this to write to I/O ports to send 2 bytes to devices.
-/// @param port The output port.
-/// @param data The data to write.
-void outports(uint16_t port, uint16_t data);
+/// @brief Reads multiple 8-bit values from the given port.
+/// @param port the port we want to read from.
+/// @param addr the location where we store the values we read.
+/// @param count the number of values we want to read.
+static inline void inportsb(unsigned short port, void *addr, unsigned long count)
+{
+    __asm__ __volatile__(
+        "cld ; rep ; insb "
+        : "=D"(addr), "=c"(count)
+        : "d"(port), "0"(addr), "1"(count));
+}
 
-void outportsm(uint16_t port, uint8_t *data, uint16_t size);
+/// @brief Reads multiple 16-bit values from the given port.
+/// @param port the port we want to read from.
+/// @param addr the location where we store the values we read.
+/// @param count the number of values we want to read.
+static inline void inportsw(unsigned short port, void *addr, unsigned long count)
+{
+    __asm__ __volatile__(
+        "cld ; rep ; insw "
+        : "=D"(addr), "=c"(count)
+        : "d"(port), "0"(addr), "1"(count));
+}
 
-/// @brief      Use this to write to I/O ports to send 4 bytes to devices.
-/// @param port The output port.
-/// @param data The data to write.
-void outportl(uint16_t port, uint32_t data);
+/// @brief Reads multiple 32-bit values from the given port.
+/// @param port the port we want to read from.
+/// @param addr the location where we store the values we read.
+/// @param count the number of values we want to read.
+static inline void inportsl(unsigned short port, void *addr, unsigned long count)
+{
+    __asm__ __volatile__(
+        "cld ; rep ; insl "
+        : "=D"(addr), "=c"(count)
+        : "d"(port), "0"(addr), "1"(count));
+}
+
+/// @brief Writes multiple 8-bit values to the given port.
+/// @param port the port we want to write to.
+/// @param addr the location where we get the values we need to write.
+/// @param count the number of values we want to write.
+static inline void outportsb(unsigned short port, void *addr, unsigned long count)
+{
+    __asm__ __volatile__(
+        "cld ; rep ; outsb "
+        : "=S"(addr), "=c"(count)
+        : "d"(port), "0"(addr), "1"(count));
+}
+
+/// @brief Writes multiple 16-bit values to the given port.
+/// @param port the port we want to write to.
+/// @param addr the location where we get the values we need to write.
+/// @param count the number of values we want to write.
+static inline void outportsw(unsigned short port, void *addr, unsigned long count)
+{
+    __asm__ __volatile__(
+        "cld ; rep ; outsw "
+        : "=S"(addr), "=c"(count)
+        : "d"(port), "0"(addr), "1"(count));
+}
+
+/// @brief Writes multiple 32-bit values to the given port.
+/// @param port the port we want to write to.
+/// @param addr the location where we get the values we need to write.
+/// @param count the number of values we want to write.
+static inline void outportsl(unsigned short port, void *addr, unsigned long count)
+{
+    __asm__ __volatile__(
+        "cld ; rep ; outsl "
+        : "=S"(addr), "=c"(count)
+        : "d"(port), "0"(addr), "1"(count));
+}

libc/inc/ipc/ipc.h

@@ -1,24 +0,0 @@
-/// @file ipc.h
-/// @brief Inter-Process Communication (IPC) structures.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
-/// See LICENSE.md for details.
-
-#pragma once
-
-/// @brief Permission details of an IPC object.
-struct ipc_perm {
-    /// Key supplied to msgget(2).
-    key_t __key;
-    /// Effective UID of owner.
-    uid_t uid;
-    /// Effective GID of owner.
-    gid_t gid;
-    /// Effective UID of creator.
-    uid_t cuid;
-    /// Effective GID of creator.
-    gid_t cgid;
-    /// Permissions.
-    unsigned short mode;
-    /// Sequence number.
-    unsigned short __seq;
-};

libc/inc/libgen.h

@@ -1,40 +1,29 @@
 /// @file libgen.h
 /// @brief String routines.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "stddef.h"
 
-// TODO: doxygen comment.
-/// @brief
-/// @param out
-/// @param cur
-/// @param sep
-/// @param max
-/// @result
-int parse_path(char *out, char **cur, char sep, size_t max);
+/// @brief Extracts the parent directory of the given path and saves it inside
+/// the given buffer, e.g., from "/home/user/test.txt" it extracts "/home/user".
+/// If the path does not contain a '/', it will return ".".
+/// @param path the path we are parsing.
+/// @param buffer the buffer where we save the directory name.
+/// @param buflen the length of the buffer.
+/// @return 1 if succesfull, or 0 if the buffer cannot contain the path.
+int dirname(const char *path, char *buffer, size_t buflen);
 
-// TODO: doxygen comment.
-/// @brief
-/// @param path
-/// @result
-char *dirname(const char *path);
-
-// TODO: doxygen comment.
-/// @brief
-/// @param path
-/// @result
-char *basename(const char *path);
+/// @brief Extract the component after the final '/'.
+/// @param path the path from which we extract the final component.
+/// @return a pointer after the final '/', or path itself it none was found.
+const char *basename(const char *path);
 
 /// @brief Return the canonicalized absolute pathname.
-/// @param path     The path we are canonicalizing.
-/// @param resolved The canonicalized path.
-/// @return
-/// If there is no error, realpath() returns a pointer to the resolved.
-/// Otherwise, it returns NULL, the contents of the array resolved
-/// are undefined, and errno is set to indicate the error.
-/// @details
-/// If resolved is NULL, then realpath() uses malloc
-/// to allocate a buffer of up to PATH_MAX bytes to hold the
-/// resolved pathname, and returns a pointer to this buffer.
-char *realpath(const char *path, char *resolved);
+/// @param path the path we are canonicalizing.
+/// @param buffer where we will store the canonicalized path.
+/// @param buflen the size of the buffer.
+/// @return If there is no error, realpath() returns a pointer to the buffer.
+/// Otherwise, it returns NULL, the contents of the array buffer are undefined,
+/// and errno is set to indicate the error.
+char *realpath(const char *path, char *buffer, size_t buflen);

libc/inc/limits.h

@@ -1,6 +1,6 @@
 /// @file limits.h
 /// @brief OS numeric limits.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -53,5 +53,8 @@
 /// Maximum number of characters in a path name.
 #define PATH_MAX 4096
 
+/// Maximum length of arguments provided to exec function.
+#define ARG_MAX 256
+
 /// Maximum pid number.
 #define PID_MAX_LIMIT 32768

libc/inc/math.h

@@ -1,6 +1,6 @@
 /// @file math.h
 /// @brief Mathematical constants and functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -17,6 +17,9 @@
 /// @brief The sign the the passed value.
 #define sign(x) ((x < 0) ? -1 : ((x > 0) ? 1 : 0))
 
+/// @brief Returns a rounded up, away from zero, to the nearest multiple of b.
+#define round_up(number, base) (((number) + (base)-1) & ~((base)-1))
+
 /// @brief e
 #define M_E 2.7182818284590452354
 

libc/inc/pwd.h

@@ -1,6 +1,6 @@
 /// @file pwd.h
 /// @brief Contains the structure and functions for managing passwords.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/readline.h

@@ -0,0 +1,14 @@
+/// @file readline.h
+/// @brief
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#include "stddef.h"
+
+/// @brief Reads a line from the file.
+/// @param fd the file descriptor.
+/// @param buffer the buffer where we place the line.
+/// @param buflen the length of the buffer.
+/// @param readlen the amount we read, if negative, we did not encounter a newline.
+/// @return 0 if we are done reading, 1 if we encountered a newline, -1 if otherwise.
+int readline(int fd, char *buffer, size_t buflen, ssize_t *read_len);

libc/inc/ring_buffer.h

@@ -1,6 +1,6 @@
 /// @file ring_buffer.h
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -124,4 +124,4 @@
     }
 
 #undef RING_BUFFER_ALLOC
-#undef RING_BUFFER_FREE
+#undef RING_BUFFER_FREE

libc/inc/sched.h

@@ -1,6 +1,6 @@
 /// @file sched.h
 /// @brief Structures and functions for managing the scheduler.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/types.h"
@@ -40,4 +40,4 @@ int sched_getparam(pid_t pid, sched_param_t *param);
 /// @brief Placed at the end of an infinite while loop, stops the process until,
 /// its next period starts. The calling process must be a periodic one.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-int waitperiod();
+int waitperiod(void);

libc/inc/signal.h

@@ -1,6 +1,6 @@
 /// @file signal.h
 /// @brief Signals definition.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdarg.h

@@ -1,6 +1,6 @@
 /// @file stdarg.h
 /// @brief Contains the macros required to manage variable number of arguments.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdbool.h

@@ -1,6 +1,6 @@
 /// @file stdbool.h
 /// @brief Defines the boolean values.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stddef.h

@@ -1,6 +1,6 @@
 /// @file stddef.h
 /// @brief Define basic data types.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -68,3 +68,13 @@ typedef unsigned int pgprot_t;
 /// Returns the alignment, in bytes, of the specified type.
 #define alignof(type) offsetof( \
     struct { char c; type member; }, member)
+
+/// Counts the number of elements of an array.
+#define count_of(x) ((sizeof(x) / sizeof((x)[0])) / ((size_t)(!(sizeof(x) % sizeof((x)[0])))))
+
+#define swap(a, b)             \
+    do {                       \
+        typeof(a) temp = (a);  \
+        (a)            = (b);  \
+        (b)            = temp; \
+    } while (0)

libc/inc/stdint.h

@@ -1,6 +1,6 @@
 /// @file stdint.h
 /// @brief Standard integer data-types.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdio.h

@@ -1,6 +1,6 @@
 /// @file stdio.h
 /// @brief Standard I/0 functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -30,11 +30,11 @@ void putchar(int character);
 /// @brief Writes the string pointed by str to the standard output (stdout)
 ///        and appends a newline character.
 /// @param str The string to send to stdout.
-void puts(char *str);
+void puts(const char *str);
 
 /// @brief Returns the next character from the standard input (stdin).
 /// @return The character received from stdin.
-int getchar();
+int getchar(void);
 
 /// @brief Reads characters from the standard input (stdin).
 /// @param str Where the characters are stored.
@@ -123,4 +123,8 @@ int sscanf(const char *str, const char *fmt, ...);
 /// @return On success, the function returns the number of items of the
 ///         argument list successfully filled. EOF otherwise.
 int fscanf(int fd, const char *fmt, ...);
-#endif
+#endif
+
+/// @brief Prints a system error message.
+/// @param s the message we prepend to the actual error message.
+void perror(const char *s);

libc/inc/stdlib.h

@@ -1,12 +1,17 @@
 /// @file stdlib.h
 /// @brief Useful generic functions and macros.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
+#ifndef __KERNEL__
+
 #include "stddef.h"
 
+#define EXIT_SUCCESS 0 ///< Successful execution of a program.
+#define EXIT_FAILURE 1 ///< Unsuccessful execution of a program.
+
 /// @brief Returns the number of usable bytes in the block pointed to by ptr.
 /// @param ptr The pointer for which we want to retrieve the usable size.
 /// @return The number of usable bytes in the block of allocated memory
@@ -38,19 +43,8 @@ void *realloc(void *ptr, size_t size);
 /// @param ptr The pointer to the allocated memory.
 void free(void *ptr);
 
-/// The maximum value returned by the rand function.
-#define RAND_MAX ((1U << 31U) - 1U)
-
-/// @brief Allows to set the seed of the random value generator.
-/// @param x The new seed.
-void srand(int x);
-
-/// @brief Generates a random value.
-/// @return The random value.
-int rand();
-
 /// @brief Cause an abnormal program termination with core-dump.
-void abort();
+void abort(void);
 
 /// @brief Tries to adds the variable to the environment.
 /// @param name      Name of the variable.
@@ -68,3 +62,38 @@ int unsetenv(const char *name);
 /// @param name Name of the variable.
 /// @return A pointer to the value, or NULL if there is no match.
 char *getenv(const char *name);
+
+#endif
+
+/// The maximum value returned by the rand function.
+#define RAND_MAX ((1U << 31U) - 1U)
+
+/// @brief Allows to set the seed of the random value generator.
+/// @param x The new seed.
+void srand(unsigned x);
+
+/// @brief Generates a random unsigned integer between 0 and RAND_MAX.
+/// @return the random value.
+unsigned rand(void);
+
+/// @brief Generates a random floating point number between 0 and 1.
+/// @return the random value.
+float randf(void);
+
+/// @brief Generates a random integer between lb and ub.
+/// @param lb the lower-bound value.
+/// @param ub the upper-bound value.
+/// @return the random value.
+int randint(int lb, int ub);
+
+/// @brief Generates a random unsigned between lb and ub.
+/// @param lb the lower-bound value.
+/// @param ub the upper-bound value.
+/// @return the random value.
+unsigned randuint(unsigned lb, unsigned ub);
+
+/// @brief Generates a random float between lb and ub.
+/// @param lb the lower-bound value.
+/// @param ub the upper-bound value.
+/// @return the random value.
+float randfloat(float lb, float ub);

libc/inc/strerror.h

@@ -1,6 +1,6 @@
 /// @file strerror.h
 /// @brief Contains the function that transfornms an errno into a string.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/string.h

@@ -1,6 +1,6 @@
 /// @file string.h
 /// @brief String routines.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -170,6 +170,15 @@ char *strtok(char *str, const char *delim);
 /// should be NULL, and saveptr should be unchanged since the previous call.
 char *strtok_r(char *str, const char *delim, char **saveptr);
 
+/// @brief Parses the string using the separator, and at each call it saves the
+/// parsed token in buffer. The pointer `string` will be modified.
+/// @param string cursor used to parse the string, it will be modified.
+/// @param separators the list of separators we are using.
+/// @param buffer the buffer where we save the parsed token.
+/// @param buflen the length of the buffer.
+/// @return 1 if we still have things to parse, 0 if we finished parsing.
+int tokenize(const char *string, char *separators, size_t *offset, char *buffer, ssize_t buflen);
+
 /// @brief Copies the values of num bytes from the location pointed by source
 /// to the memory block pointed by destination.
 /// @param dst Pointer to the destination array where the content is to be
@@ -307,4 +316,4 @@ char *replace_char(char *str, char find, char replace);
 ///        referenced by p.
 /// @param mode File mode that encodes access permissions and file type.
 /// @param p    Buffer used to hold the string representation of file mode m.
-void strmode(mode_t mode, char *p);
+void strmode(mode_t mode, char *p);

libc/inc/sys/bitops.h

@@ -1,40 +1,50 @@
 /// @file bitops.h
 /// @brief Bitmasks functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
-#define bit_set(V, B)          ((V) | (1U << (B)))   ///< Sets the given bit.
-#define bit_clear(V, B)        ((V) & ~(1U << (B)))  ///< Clears the given bit.
-#define bit_flip(V, B)         ((V) ^ (1U << (B)))   ///< Flips the given bit.
-#define bit_set_assign(V, B)   ((V) |= (1U << (B)))  ///< Sets the given bit, permanently.
-#define bit_clear_assign(V, B) ((V) &= ~(1U << (B))) ///< Clears the given bit, permanently.
-#define bit_flip_assign(V, B)  ((V) ^= (1U << (B)))  ///< Flips the given bit, permanently.
-#define bit_check(V, B)        ((V) & (1U << (B)))   ///< Checks if the given bit is 1.
+#define bit_set(V, B)              ((V) | (1U << (B)))                                   ///< Sets the given bit.
+#define bit_clear(V, B)            ((V) & ~(1U << (B)))                                  ///< Clears the given bit.
+#define bit_flip(V, B)             ((V) ^ (1U << (B)))                                   ///< Flips the given bit.
+#define bit_check(V, B)            ((V) & (1U << (B)))                                   ///< Checks if the given bit is 1.
+#define bit_toggle(V, B, C)        ((C) ? bit_set(V, B) : bit_clear(V, B))               ///< Sets the given bit based on control bit C.
+#define bit_set_assign(V, B)       ((V) |= (1U << (B)))                                  ///< Sets the given bit, permanently.
+#define bit_clear_assign(V, B)     ((V) &= ~(1U << (B)))                                 ///< Clears the given bit, permanently.
+#define bit_flip_assign(V, B)      ((V) ^= (1U << (B)))                                  ///< Flips the given bit, permanently.
+#define bit_toggle_assign(V, B, C) ((C) ? bit_set_assign(V, B) : bit_clear_assign(V, B)) ///< Sets the given bit based on control bit C.
 
 #define bitmask_set(V, M)          ((V) | (M))   ///< Sets the bits identified by the mask.
 #define bitmask_clear(V, M)        ((V) & ~(M))  ///< Clears the bits identified by the mask.
 #define bitmask_flip(V, M)         ((V) ^ (M))   ///< Flips the bits identified by the mask.
+#define bitmask_check(V, M)        ((V) & (M))   ///< Checks if the bits identified by the mask are all 1.
 #define bitmask_set_assign(V, M)   ((V) |= (M))  ///< Sets the bits identified by the mask, permanently.
 #define bitmask_clear_assign(V, M) ((V) &= ~(M)) ///< Clears the bits identified by the mask, permanently.
 #define bitmask_flip_assign(V, M)  ((V) ^= (M))  ///< Flips the bits identified by the mask, permanently.
-#define bitmask_check(V, M)        ((V) & (M))   ///< Checks if the bits identified by the mask are all 1.
 
 /// @brief Finds the first bit at zero, starting from the less significative bit.
+/// @param value the value we need to analyze.
+/// @return the position of the first zero bit.
 static inline int find_first_zero(unsigned long value)
 {
-    for (int i = 0; i < 32; ++i)
-        if (!bit_check(value, i))
+    for (int i = 0; i < 32; ++i) {
+        if (!bit_check(value, i)) {
             return i;
+        }
+    }
     return 0;
 }
 
 /// @brief Finds the first bit not zero, starting from the less significative bit.
+/// @param value the value we need to analyze.
+/// @return the position of the first non-zero bit.
 static inline int find_first_non_zero(unsigned long value)
 {
-    for (int i = 0; i < 32; ++i)
-        if (bit_check(value, i))
+    for (int i = 0; i < 32; ++i) {
+        if (bit_check(value, i)) {
             return i;
+        }
+    }
     return 0;
-}
+}

libc/inc/sys/dirent.h

@@ -1,6 +1,6 @@
 /// @file dirent.h
 /// @brief Functions used to manage directories.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -21,22 +21,23 @@ enum {
     DT_WHT     = 14
 };
 
+/// @brief Characters describing the direactory entry.
 static const char dt_char_array[] = {
     '?', // DT_UNKNOWN = 0,
-    'p', //DT_FIFO = 1,
-    'c', //DT_CHR  = 2,
+    'p', // DT_FIFO = 1,
+    'c', // DT_CHR  = 2,
     '*',
-    'd', //DT_DIR  = 4,
+    'd', // DT_DIR  = 4,
     '*',
-    'b', //DT_BLK  = 6,
+    'b', // DT_BLK  = 6,
     '*',
-    '-', //DT_REG  = 8,
+    '-', // DT_REG  = 8,
     '*',
-    'l', //DT_LNK  = 10,
+    'l', // DT_LNK  = 10,
     '*',
-    's', //DT_SOCK = 12,
+    's', // DT_SOCK = 12,
     '*',
-    '?', //DT_WHT  = 14
+    '?', // DT_WHT  = 14
 };
 
 /// Directory entry.
@@ -46,4 +47,4 @@ typedef struct dirent_t {
     unsigned short d_reclen; ///< Length of this linux_dirent.
     unsigned short d_type;   ///< type of the directory entry.
     char d_name[NAME_MAX];   ///< Filename (null-terminated)
-} dirent_t;
+} dirent_t;

libc/inc/sys/errno.h

@@ -1,11 +1,11 @@
 /// @file errno.h
 /// @brief System call errors definition.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
-extern int *__geterrno();
+extern int *__geterrno(void);
 
 /// Provide easy access to the error number.
 #define errno (*__geterrno())
@@ -20,7 +20,7 @@ extern int *__geterrno();
 #define ENOEXEC         8 ///< Exec format error.
 #define EBADF           9 ///< Bad file number.
 #define ECHILD          10 ///< No child processes.
-#define EAGAIN          11 ///< Try again.
+#define EAGAIN          11 ///< Resource temporarily unavailable.
 #define ENOMEM          12 ///< Out of memory.
 #define EACCES          13 ///< Permission denied.
 #define EFAULT          14 ///< Bad address.

libc/inc/sys/ioctl.h

@@ -1,6 +1,6 @@
 /// @file ioctl.h
 /// @brief Input/Output ConTroL (IOCTL) functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -11,4 +11,4 @@
 /// @param request The device-dependent request code
 /// @param data    An untyped pointer to memory.
 /// @return Return value depends on REQUEST. Usually -1 indicates error.
-int ioctl(int fd, unsigned long int request, void *data);
+int ioctl(int fd, unsigned long int request, void *data);

libc/inc/sys/ipc.h

@@ -0,0 +1,43 @@
+/// @file ipc.h
+/// @brief Inter-Process Communication (IPC) structures.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+#include "sys/types.h"
+#include "stddef.h"
+
+#define IPC_CREAT  01000 ///< Create key if key does not exist.
+#define IPC_EXCL   02000 ///< Fail if key exists.
+#define IPC_NOWAIT 04000 ///< Return error on wait.
+#define IPC_RMID   0     ///< Remove identifier.
+#define IPC_SET    1     ///< Set `ipc_perm' options.
+#define IPC_STAT   2     ///< Get `ipc_perm' options.
+#define IPC_INFO   3     ///< See ipcs.
+
+#define IPC_PRIVATE ((key_t)0) ///< assures getting a new ipc_key.
+
+/// @brief Permission details of an IPC object.
+struct ipc_perm {
+    /// Key associated to the IPC.
+    key_t key;
+    /// Effective UID of owner.
+    uid_t uid;
+    /// Effective GID of owner.
+    gid_t gid;
+    /// Effective UID of creator.
+    uid_t cuid;
+    /// Effective GID of creator.
+    gid_t cgid;
+    /// Permissions.
+    unsigned short mode;
+    /// Sequence number.
+    unsigned short __seq;
+};
+
+/// @brief Returns a possible IPC key based upon the filepath and the id.
+/// @param path The file path.
+/// @param id the project id.
+/// @return the IPC key.
+key_t ftok(char *path, int id);

libc/inc/sys/kernel_levels.h

@@ -0,0 +1,17 @@
+/// @file   kernel_levels.h
+/// @brief
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+// Integer equivalents of KERN_<LEVEL>
+#define LOGLEVEL_DEFAULT (-1) ///< default-level messages.
+#define LOGLEVEL_EMERG   0    ///< system is unusable.
+#define LOGLEVEL_ALERT   1    ///< action must be taken immediately.
+#define LOGLEVEL_CRIT    2    ///< critical conditions.
+#define LOGLEVEL_ERR     3    ///< error conditions.
+#define LOGLEVEL_WARNING 4    ///< warning conditions.
+#define LOGLEVEL_NOTICE  5    ///< normal but significant condition.
+#define LOGLEVEL_INFO    6    ///< informational.
+#define LOGLEVEL_DEBUG   7    ///< debug-level messages.

libc/inc/sys/list_head.h

@@ -1,6 +1,6 @@
 /// @file list_head.h
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -22,31 +22,37 @@ typedef struct list_head {
 #define list_entry(ptr, type, member) container_of(ptr, type, member)
 
 /// @brief Iterates over a list.
-/// @param pos    The &list_head to use as a loop cursor.
-/// @param head   The head for your list.
+/// @param pos the name of the iterator used to visit the list.
+/// @param head the head for your list.
 #define list_for_each(pos, head) \
     for ((pos) = (head)->next; (pos) != (head); (pos) = (pos)->next)
 
-/// @brief Iterates over a list backwards.
-/// @param pos    The &list_head to use as a loop cursor.
-/// @param head   The head for your list.
-#define list_for_each_prev(pos, head) \
-    for ((pos) = (head)->prev; (pos) != (head); (pos) = (pos)->prev)
-
 /// @brief Iterates over a list safe against removal of list entry.
-/// @param pos    The &list_head to use as a loop cursor.
-/// @param store  Another &list_head to use as temporary storage.
-/// @param head   The head for your list.
+/// @param pos the name of the iterator used to visit the list.
+/// @param store another list iterator to use as temporary storage.
+/// @param head the head for your list.
 #define list_for_each_safe(pos, store, head)                           \
     for ((pos) = (head)->next, (store) = (pos)->next; (pos) != (head); \
          (pos) = (store), (store) = (pos)->next)
 
-/// @brief Iterates over a list.
-/// @param pos    The &list_head to use as a loop cursor.
-/// @param head   The head for your list.
+/// @brief Iterates over a list, but declares the iterator.
+/// @param pos the name of the iterator used to visit the list.
+/// @param head the head for your list.
 #define list_for_each_decl(pos, head) \
     for (list_head * (pos) = (head)->next; (pos) != (head); (pos) = (pos)->next)
 
+/// @brief Iterates over a list backwards.
+/// @param pos the name of the iterator used to visit the list.
+/// @param head the head for your list.
+#define list_for_each_prev(pos, head) \
+    for ((pos) = (head)->prev; (pos) != (head); (pos) = (pos)->prev)
+
+/// @brief Iterates over a list backwards, but declares the iterator.
+/// @param pos the name of the iterator used to visit the list.
+/// @param head the head for your list.
+#define list_for_each_prev_decl(pos, head) \
+    for (list_head * (pos) = (head)->prev; (pos) != (head); (pos) = (pos)->prev)
+
 /// @brief Initializes the list_head.
 /// @param head The head of your list.
 static inline void list_head_init(list_head *head)
@@ -62,13 +68,15 @@ static inline int list_head_empty(const list_head *head)
     return head->next == head;
 }
 
-/// @brief Initializes the list_head.
-/// @param head The head for your list.
+/// @brief Computes the size of the list.
+/// @param head The head of the list.
+/// @return the size of the list.
 static inline unsigned list_head_size(const list_head *head)
 {
     unsigned size = 0;
-    if (!list_head_empty(head))
+    if (!list_head_empty(head)) {
         list_for_each_decl(it, head) size += 1;
+    }
     return size;
 }
 
@@ -160,3 +168,32 @@ static inline void list_head_append(list_head *main, list_head *secondary)
         list_head_init(secondary);
     }
 }
+
+/// @brief Replaces entry1 with entry2, entry1 will be removed from the list.
+/// @param entry1 the first entry to remove.
+/// @param entry2 the second entry which will take the place of the first entry.
+static inline void list_head_replace(list_head *entry1, list_head *entry2)
+{
+    // First we need to remove the second entry.
+    list_head_remove(entry2);
+    // Then, we can place second entry where the first entry is.
+    entry2->next       = entry1->next;
+    entry2->next->prev = entry2;
+    entry2->prev       = entry1->prev;
+    entry2->prev->next = entry2;
+    // Re-initialize the first entry.
+    list_head_init(entry1);
+}
+
+/// @brief Swaps entry1 and entry2 inside the list.
+/// @param entry1 the first entry.
+/// @param entry2 the second entry.
+static inline void list_head_swap(list_head *entry1, list_head *entry2)
+{
+    list_head *pos = entry2->prev;
+    list_head_replace(entry1, entry2);
+    if (pos == entry1) {
+        pos = entry2;
+    }
+    list_head_insert_after(entry1, pos);
+}

libc/inc/sys/list_head_algorithm.h

@@ -0,0 +1,47 @@
+/// @file list_head_algorithm.h
+/// @author Enrico Fraccaroli (enry.frak@gmail.com)
+/// @brief Some general algorithm that might come in handy while using list_head.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+#include "list_head.h"
+
+/// @brief list_head comparison function.
+typedef int (*list_head_compare)(const list_head *, const list_head *);
+
+/// @brief -
+/// @param list
+/// @param compare
+static inline void list_head_sort(list_head *list, list_head_compare compare)
+{
+    list_head *current = NULL, *index = NULL, *next = NULL;
+    // Check whether list is empty
+    if (!list_head_empty(list)) {
+        // Keeps track if we need to restart the outer loop.
+        int restart = 0;
+        // Current will point to head
+        for (current = list->next; current->next != list;) {
+            // Save pointer to next.
+            next = current->next;
+            // Reset restart flag.
+            restart = 0;
+            // Index will point to node next to current
+            for (index = current->next; index != list; index = index->next) {
+                // If current's data is greater than index's data, swap the data of
+                // current and index
+                if (compare(current, index)) {
+                    list_head_swap(index, current);
+                    restart = 1;
+                }
+            }
+            // Check if we need to restart.
+            if (restart) {
+                current = list->next;
+            } else {
+                current = next;
+            }
+        }
+    }
+}

libc/inc/sys/mman.h

@@ -0,0 +1,30 @@
+/// @file mman.h
+/// @author Enrico Fraccaroli (enry.frak@gmail.com)
+/// @brief Functions for managing mappings in virtual address space.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+#include "stddef.h"
+
+#define PROT_READ  0x1 ///< Page can be read.
+#define PROT_WRITE 0x2 ///< Page can be written.
+#define PROT_EXEC  0x4 ///< Page can be executed.
+
+#define MAP_SHARED  0x01 ///< The memory is shared.
+#define MAP_PRIVATE 0x02 ///< The memory is private.
+
+#ifndef __KERNEL__
+
+void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset);
+
+int munmap(void *addr, size_t length);
+
+#else
+
+void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset);
+
+int sys_munmap(void *addr, size_t length);
+
+#endif

libc/inc/sys/msg.h

@@ -1,31 +1,48 @@
 /// @file msg.h
 /// @brief Definition of structure for managing message queues.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
-#include "sys/types.h"
+#include "sys/ipc.h"
 #include "stddef.h"
+#include "sys/types.h"
 #include "time.h"
-#include "ipc.h"
 
-/// Type for storing the number of messages in a message queue.
-typedef unsigned int msgqnum_t;
+/// The maximum size for a message text.
+#define MSGMAX 8192
+/// The default maximum size in bytes of a message queue.
+#define MSGMNB 16384
 
-/// Type for storing the number of bytes in a message queue.
-typedef unsigned int msglen_t;
+/// Specify that we should not treat as an error if the message we are trying to
+/// return to the user, is too big. That message will be truncated to fit the
+/// user-defined reading buffer. If not specified, the message is kept in the
+/// queue, and an error is returned.
+#define MSG_NOERROR 010000
 
 /// @brief Buffer to use with the message queue IPC.
-typedef struct msgbuf {
+struct msgbuf {
     /// Type of the message.
     long mtype;
     /// Text of the message.
     char mtext[1];
-} msgbuf_t;
+};
+
+/// Keeps track of a stored message.
+struct msg {
+    /// Pointer to the next message on queue.
+    struct msg *msg_next;
+    /// The type of message.
+    long msg_type;
+    /// Pointer to the beginning of the message.
+    char *msg_ptr;
+    /// The length of the message.
+    size_t msg_size;
+};
 
 /// @brief Message queue data structure.
-typedef struct msqid_ds {
+struct msqid_ds {
     /// Ownership and permissions.
     struct ipc_perm msg_perm;
     /// Time of last msgsnd(2).
@@ -35,26 +52,30 @@ typedef struct msqid_ds {
     /// Time of creation or last modification by msgctl().
     time_t msg_ctime;
     /// Number of bytes in queue.
-    unsigned long msg_cbytes;
+    unsigned short msg_cbytes;
     /// Number of messages in queue.
-    msgqnum_t msg_qnum;
+    unsigned short msg_qnum;
     /// Maximum number of bytes in queue.
-    msglen_t msg_qbytes;
+    unsigned short msg_qbytes;
     /// PID of last msgsnd(2).
     pid_t msg_lspid;
     /// PID of last msgrcv(2).
     pid_t msg_lrpid;
-} msqid_ds_t;
+};
 
 #ifdef __KERNEL__
 
+/// @brief Initializes the message queue system.
+/// @return 0 on success, 1 on failure.
+int msq_init(void);
+
 /// @brief Get a System V message queue identifier.
 /// @param key can be used either to obtain the identifier of a previously
 /// created message queue, or to create a new set.
 /// @param msgflg controls the behaviour of the function.
 /// @return the message queue identifier, -1 on failure, and errno is set to
 /// indicate the error.
-long sys_msgget(key_t key, int msgflg);
+int sys_msgget(key_t key, int msgflg);
 
 /// @brief Used to send messages.
 /// @param msqid the message queue identifier.
@@ -62,7 +83,7 @@ long sys_msgget(key_t key, int msgflg);
 /// @param msgsz specifies the size in bytes of mtext.
 /// @param msgflg specifies the action to be taken in case of specific events.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long sys_msgsnd(int msqid, msgbuf_t *msgp, size_t msgsz, int msgflg);
+int sys_msgsnd(int msqid, const void *msgp, size_t msgsz, int msgflg);
 
 /// @brief Used to receive messages.
 /// @param msqid the message queue identifier.
@@ -74,15 +95,16 @@ long sys_msgsnd(int msqid, msgbuf_t *msgp, size_t msgsz, int msgflg);
 /// - msgtyp  < 0: the first message of the lowest type that is less than or
 ///                equal to the absolute value of msgtyp is received.
 /// @param msgflg specifies the action to be taken in case of specific events.
-/// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long sys_msgrcv(int msqid, msgbuf_t *msgp, size_t msgsz, long msgtyp, int msgflg);
+/// @return the number of bytes actually copied on success, -1 on failure and
+/// errno is set to indicate the error.
+ssize_t sys_msgrcv(int msqid, void *msgp, size_t msgsz, long msgtyp, int msgflg);
 
 /// @brief Message queue control operations.
 /// @param msqid the message queue identifier.
 /// @param cmd The command to perform.
 /// @param buf used with IPC_STAT and IPC_SET.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long sys_msgctl(int msqid, int cmd, msqid_ds_t *buf);
+int sys_msgctl(int msqid, int cmd, struct msqid_ds *buf);
 
 #else
 
@@ -92,7 +114,7 @@ long sys_msgctl(int msqid, int cmd, msqid_ds_t *buf);
 /// @param msgflg controls the behaviour of the function.
 /// @return the message queue identifier, -1 on failure, and errno is set to
 /// indicate the error.
-long msgget(key_t key, int msgflg);
+int msgget(key_t key, int msgflg);
 
 /// @brief Used to send messages.
 /// @param msqid the message queue identifier.
@@ -100,7 +122,7 @@ long msgget(key_t key, int msgflg);
 /// @param msgsz specifies the size in bytes of mtext.
 /// @param msgflg specifies the action to be taken in case of specific events.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long msgsnd(int msqid, msgbuf_t *msgp, size_t msgsz, int msgflg);
+int msgsnd(int msqid, const void *msgp, size_t msgsz, int msgflg);
 
 /// @brief Used to receive messages.
 /// @param msqid the message queue identifier.
@@ -112,14 +134,15 @@ long msgsnd(int msqid, msgbuf_t *msgp, size_t msgsz, int msgflg);
 /// - msgtyp  < 0: the first message of the lowest type that is less than or
 ///                equal to the absolute value of msgtyp is received.
 /// @param msgflg specifies the action to be taken in case of specific events.
-/// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long msgrcv(int msqid, msgbuf_t *msgp, size_t msgsz, long msgtyp, int msgflg);
+/// @return the number of bytes actually copied on success, -1 on failure and
+/// errno is set to indicate the error.
+ssize_t msgrcv(int msqid, void *msgp, size_t msgsz, long msgtyp, int msgflg);
 
 /// @brief Message queue control operations.
 /// @param msqid the message queue identifier.
 /// @param cmd The command to perform.
 /// @param buf used with IPC_STAT and IPC_SET.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long msgctl(int msqid, int cmd, msqid_ds_t *buf);
+int msgctl(int msqid, int cmd, struct msqid_ds *buf);
 
-#endif
+#endif

libc/inc/sys/reboot.h

@@ -1,6 +1,6 @@
 /// @file reboot.h
 /// @brief Defines the values required to issue a reboot.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/sem.h

@@ -1,27 +1,87 @@
 /// @file sem.h
 /// @brief Definition of structure for managing semaphores.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
 #include "sys/types.h"
 #include "stddef.h"
+#include "sys/ipc.h"
 #include "time.h"
-#include "ipc.h"
+
+#define SEM_UNDO 0x1000 ///< Undo the operation on exit.
+
+/// @defgroup SemaphoreCommands semctl commands
+/// @brief List of commands for semctl function.
+/// @{
+
+#define GETPID   11 ///< Get sempid.
+#define GETVAL   12 ///< Get semval.
+#define GETALL   13 ///< Get all semval's.
+#define GETNCNT  14 ///< Get semncnt.
+#define GETZCNT  15 ///< Get semzcnt.
+#define SETVAL   16 ///< Set semval.
+#define SETALL   17 ///< Set all semval's.
+#define SEM_STAT 18 ///< Return a semid_ds structure.
+#define SEM_INFO 19 ///< Return a seminfo structure.
+
+/// }@
+
+#define SEM_SET_MAX 256
+
+/// @brief Optional argument for semctl() function
+union semun {
+    /// @brief Value for SETVAL.
+    int val;
+    /// @brief Buffer for IPC_STAT & IPC_SET.
+    struct semid_ds *buf;
+    /// @brief Array for GETALL & SETALL.
+    unsigned short *array;
+    /// @brief Buffer for IPC_INFO.
+    struct seminfo *__buf;
+};
+
+/// @brief Single Semaphore.
+struct sem {
+    /// @brief Process ID of the last operation.
+    pid_t sem_pid;
+    /// @brief Semaphore Value.
+    unsigned short sem_val;
+    /// @brief Number of processes waiting for the semaphore.
+    unsigned short sem_ncnt;
+    /// @brief Number of processes waiting for the value to become 0.
+    unsigned short sem_zcnt;
+};
+
+/// @brief Semaphore set
+struct semid_ds {
+    /// @brief Ownership and permissions.
+    struct ipc_perm sem_perm;
+    /// @brief Last semop time.
+    time_t sem_otime;
+    /// @brief Last change time.
+    time_t sem_ctime;
+    /// @brief Number of semaphores in set.
+    unsigned short sem_nsems;
+};
 
 /// @brief Buffer to use with the semaphore IPC.
 struct sembuf {
-    /// Semaphore index in array.
+    /// @brief Semaphore index in array.
     unsigned short sem_num;
-    /// Semaphore operation.
+    /// @brief Semaphore operation.
     short sem_op;
-    /// Operation flags.
+    /// @brief Operation flags.
     short sem_flg;
 };
 
 #ifdef __KERNEL__
 
+/// @brief Initializes the semaphore system.
+/// @return 0 on success, 1 on failure.
+int sem_init(void);
+
 /// @brief Get a System V semaphore set identifier.
 /// @param key can be used either to obtain the identifier of a previously
 /// created semaphore set, or to create a new set.
@@ -44,7 +104,7 @@ long sys_semop(int semid, struct sembuf *sops, unsigned nsops);
 /// @param cmd the command to perform.
 /// @param arg
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long sys_semctl(int semid, int semnum, int cmd, unsigned long arg);
+long sys_semctl(int semid, int semnum, int cmd, union semun *arg);
 
 #else
 
@@ -70,6 +130,6 @@ long semop(int semid, struct sembuf *sops, unsigned nsops);
 /// @param cmd the command to perform.
 /// @param arg
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long semctl(int semid, int semnum, int cmd, unsigned long arg);
+long semctl(int semid, int semnum, int cmd, union semun *arg);
 
-#endif
+#endif

libc/inc/sys/shm.h

@@ -1,14 +1,14 @@
 /// @file shm.h
 /// @brief Definition of structure for managing shared memories.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
 #include "sys/types.h"
 #include "stddef.h"
+#include "sys/ipc.h"
 #include "time.h"
-#include "ipc.h"
 
 /// Data type for storing the number of attaches.
 typedef unsigned long shmatt_t;
@@ -19,27 +19,22 @@ struct shmid_ds {
     struct ipc_perm shm_perm;
     /// Size of segment in bytes.
     size_t shm_segsz;
-    /// Time of last shmat().
+    /// Time of last attach.
     time_t shm_atime;
-    /// Time of last shmdt().
+    /// Time of last detach.
     time_t shm_dtime;
-    /// Time of last change by shmctl().
+    /// Time of last change.
     time_t shm_ctime;
     /// Pid of creator.
     pid_t shm_cpid;
-    /// Pid of last shmop.
+    /// Pid of last operator.
     pid_t shm_lpid;
     /// Number of current attaches.
     shmatt_t shm_nattch;
-    /// Pointer to the next shared memory data structure.
-    struct shmid_ds *next;
-    /// Where shm created is memorized, should be a file.
-    void *shm_location;
 };
 
 #if 0
 
-#include "ipc.h"
 #include "debug.h"
 #include "time.h"
 #include "kheap.h"
@@ -56,20 +51,6 @@ struct shmid_ds {
 #define SHM_W      0200
 //==============================================================================
 
-//======== Flags for shmat =====================================================
-// Attach read-only else read-write.
-#define SHM_RDONLY 010000
-
-// Round attach address to SHMLBA.
-#define SHM_RND    020000
-
-// Take-over region on attach.
-#define SHM_REMAP  040000
-
-// Execution access.
-#define SHM_EXEC   0100000
-//==============================================================================
-
 //======== Commands for shmctl =================================================
 // Lock segment (root only).
 #define SHM_LOCK   11
@@ -98,51 +79,27 @@ struct shmid_ds {
 // Don't check for reservations.
 #define SHM_NORESERVE 010000
 
-/// @@brief Syscall Service Routine: Shared memory control operation.
-int syscall_shmctl(int *args);
-
-/// @@brief Syscall Service Routine: Get shared memory segment.
-int syscall_shmget(int *args);
-
-/// @@brief Syscall Service Routine: Attach shared memory segment.
-void *syscall_shmat(int *args);
-
-/// @@brief Syscall  Service Routine: Detach shared memory segment.
-int syscall_shmdt(int *args);
-
-/// @@brief User Wrapper: Shared memory control operation.
-int shmctl(int shmid, int cmd, struct shmid_ds *buf);
-
-/// @@brief User Wrapper: Get shared memory segment.
-int shmget(key_t key, size_t size, int flags);
-
-/// @@brief User Wrapper: Attach shared memory segment.
-void *shmat(int shmid, void *shmaddr, int flag);
-
-/// @@brief User Wrapper: Detach shared memory segment.
-int shmdt(void *shmaddr);
-
-/// @@brief Find shmid_ds on list.
-struct shmid_ds *find_shm_fromid(int shmid);
-
-/// @@brief Find shmid_ds on list.
-struct shmid_ds *find_shm_fromkey(key_t key);
-
-/// @@brief shmid_ds on list.
-struct shmid_ds *find_shm_fromvaddr(void *shmvaddr);
-
 #endif
 
+#define SHM_RDONLY 010000  ///< Attach read-only else read-write.
+#define SHM_RND    020000  ///< Round attach address to SHMLBA.
+#define SHM_REMAP  040000  ///< Take-over region on attach.
+#define SHM_EXEC   0100000 ///< Execution access.
+
 #ifdef __KERNEL__
 
+/// @brief Initializes the shared memory.
+/// @return 0 on success, 1 on failure.
+int shm_init(void);
+
 /// @brief Get a System V shared memory identifier.
 /// @param key can be used either to obtain the identifier of a previously
 /// created shared memory, or to create a new one.
 /// @param size of the shared memory, rounded up to a multiple of PAGE_SIZE.
-/// @param flag controls the behaviour of the function.
+/// @param shmflg controls the behaviour of the function.
 /// @return the shared memory identifier, -1 on failure, and errno is set to
 /// indicate the error.
-long sys_shmget(key_t key, size_t size, int flag);
+long sys_shmget(key_t key, size_t size, int shmflg);
 
 /// @brief Attaches the shared memory segment identified by shmid to the address
 /// space of the calling process.
@@ -151,7 +108,7 @@ long sys_shmget(key_t key, size_t size, int flag);
 /// @param shmflg controls the behaviour of the function.
 /// @return returns the address of the attached shared memory segment; on error
 /// (void *) -1 is returned, and errno is set to indicate the error.
-void * sys_shmat(int shmid, const void *shmaddr, int shmflg);
+void *sys_shmat(int shmid, const void *shmaddr, int shmflg);
 
 /// @brief Detaches the shared memory segment located at the address specified
 /// by shmaddr from the address space of the calling process
@@ -174,10 +131,10 @@ long sys_shmctl(int shmid, int cmd, struct shmid_ds *buf);
 /// @param key can be used either to obtain the identifier of a previously
 /// created shared memory, or to create a new one.
 /// @param size of the shared memory, rounded up to a multiple of PAGE_SIZE.
-/// @param flag controls the behaviour of the function.
+/// @param shmflg controls the behaviour of the function.
 /// @return the shared memory identifier, -1 on failure, and errno is set to
 /// indicate the error.
-long shmget(key_t key, size_t size, int flag);
+long shmget(key_t key, size_t size, int shmflg);
 
 /// @brief Attaches the shared memory segment identified by shmid to the address
 /// space of the calling process.
@@ -186,7 +143,7 @@ long shmget(key_t key, size_t size, int flag);
 /// @param shmflg controls the behaviour of the function.
 /// @return returns the address of the attached shared memory segment; on error
 /// (void *) -1 is returned, and errno is set to indicate the error.
-void * shmat(int shmid, const void *shmaddr, int shmflg);
+void *shmat(int shmid, const void *shmaddr, int shmflg);
 
 /// @brief Detaches the shared memory segment located at the address specified
 /// by shmaddr from the address space of the calling process
@@ -203,4 +160,4 @@ long shmdt(const void *shmaddr);
 /// failure and errno is set to indicate the error.
 long shmctl(int shmid, int cmd, struct shmid_ds *buf);
 
-#endif
+#endif

libc/inc/sys/stat.h

@@ -1,6 +1,6 @@
 /// @file stat.h
 /// @brief Stat functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -39,4 +39,4 @@ int rmdir(const char *path);
 /// @return file descriptor number, -1 otherwise and errno is set to indicate the error.
 /// @details
 /// It is equivalent to: open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)
-int creat(const char *path, mode_t mode);
+int creat(const char *path, mode_t mode);

libc/inc/sys/types.h

@@ -1,6 +1,6 @@
 /// @file types.h
 /// @brief Collection of Kernel datatype
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/unistd.h

@@ -1,13 +1,13 @@
 /// @file unistd.h
 /// @brief Functions used to manage files.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
 #include "sys/types.h"
-#include "sys/dirent.h"
 #include "stddef.h"
+#include "sys/dirent.h"
 
 #define STDIN_FILENO  0 ///< Standard input.
 #define STDOUT_FILENO 1 ///< Standard output.
@@ -25,7 +25,7 @@ ssize_t read(int fd, void *buf, size_t nbytes);
 /// @param buf    The buffer collecting data to written.
 /// @param nbytes The number of bytes to write.
 /// @return       The number of written bytes.
-ssize_t write(int fd, void *buf, size_t nbytes);
+ssize_t write(int fd, const void *buf, size_t nbytes);
 
 /// @brief Opens the file specified by pathname.
 /// @param pathname A pathname for a file.
@@ -54,13 +54,26 @@ off_t lseek(int fd, off_t offset, int whence);
 /// @return
 int unlink(const char *path);
 
+/// @brief Creates a symbolic link.
+/// @param linkname the name of the link.
+/// @param path the entity it is linking to.
+/// @return 0 on success, a negative number if fails and errno is set.
+int symlink(const char *linkname, const char *path);
+
+/// @brief Read the symbolic link, if present.
+/// @param file the file for which we want to read the symbolic link information.
+/// @param buffer the buffer where we will store the symbolic link path.
+/// @param bufsize the size of the buffer.
+/// @return The number of read characters on success, -1 otherwise and errno is set to indicate the error.
+int readlink(const char *path, char *buffer, size_t bufsize);
+
 /// @brief Wrapper for exit system call.
 /// @param status The exit status.
 extern void exit(int status);
 
 /// @brief Returns the process ID (PID) of the calling process.
 /// @return pid_t process identifier.
-extern pid_t getpid();
+extern pid_t getpid(void);
 
 ///@brief  Return session id of the given process.
 ///        If pid == 0 return the SID of the calling process
@@ -78,7 +91,7 @@ extern pid_t getsid(pid_t pid);
 ///       is made the same as its process ID).
 ///@return On success return SID of the session just created
 ///        Otherwise return -1 with errno : EPERM 
-extern pid_t setsid();
+extern pid_t setsid(void);
 
 ///@brief returns the Process Group ID (PGID) of the process specified by pid.
 /// If pid is zero, the process ID of the calling process is used.
@@ -95,7 +108,7 @@ int setpgid(pid_t pid, pid_t pgid);
 
 ///@brief returns the group ID of the calling process.
 ///@return GID of the current process
-extern pid_t getgid();
+extern pid_t getgid(void);
 
 ///@brief sets the effective group ID of the calling process.
 ///@param pid process identifier to 
@@ -105,7 +118,7 @@ extern int setgid(pid_t pid);
 
 ///@brief Returns the User ID of the calling process.
 ///@return User ID of the current process.
-extern uid_t getuid();
+extern uid_t getuid(void);
 
 ///@brief Sets the effective User ID of the calling process.
 ///@param uid the new User ID.
@@ -115,14 +128,14 @@ extern int setuid(uid_t uid);
 
 /// @brief Returns the parent process ID (PPID) of the calling process.
 /// @return pid_t parent process identifier.
-extern pid_t getppid();
+extern pid_t getppid(void);
 
 /// @brief Clone the calling process, but without copying the whole address space.
 ///        The calling process is suspended until the new process exits or is
 ///        replaced by a call to `execve'.
 /// @return Return -1 for errors, 0 to the new process, and the process ID of
 ///         the new process to the old process.
-extern pid_t fork();
+extern pid_t fork(void);
 
 /// @brief Replaces the current process image with a new process image (argument list).
 /// @param path The absolute path to the binary file to execute.
@@ -238,7 +251,7 @@ int fchdir(int fd);
 /// @return On success, the number of bytes read is returned.  On end of
 ///         directory, 0 is returned.  On error, -1 is returned, and errno is set
 ///         appropriately.
-int getdents(int fd, dirent_t *dirp, unsigned int count);
+ssize_t getdents(int fd, dirent_t *dirp, unsigned int count);
 
 /// @brief Send signal to calling thread after desired seconds.
 /// @param seconds the amount of seconds.
@@ -246,4 +259,4 @@ int getdents(int fd, dirent_t *dirp, unsigned int count);
 /// shall return a non-zero value that is the number of seconds until the
 /// previous request would have generated a SIGALRM signal. Otherwise, alarm()
 /// shall return 0.
-int alarm(int seconds);
+unsigned alarm(int seconds);

libc/inc/sys/utsname.h

@@ -1,6 +1,6 @@
 /// @file utsname.h
 /// @brief Functions used to provide information about the machine & OS.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/wait.h

@@ -1,6 +1,6 @@
 /// @file wait.h
 /// @brief Event management functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/system/syscall_types.h

@@ -1,6 +1,6 @@
 /// @file syscall_types.h
 /// @brief System Call numbers.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -207,6 +207,17 @@
         return (type)(res);                                \
     } while (0)
 
+// Few things about what follows:
+//
+// 1. The symbol "=", is a a constraint modifier, and it means that the operand
+//    is write-only, meaning that the previous value is discarded and replaced
+//    by output data.
+//
+// 2. Using "0" here specifies that the input is read from a variable which also
+//    serves as an output, the 0-th output variable in this case.
+//
+//
+
 /// @brief Heart of the code that calls a system call with 0 parameters.
 #define __inline_syscall0(res, name) \
     __asm__ __volatile__("int $0x80" \
@@ -214,42 +225,39 @@
                          : "0"(__NR_##name))
 
 /// @brief Heart of the code that calls a system call with 1 parameter.
-#define __inline_syscall1(res, name, arg1)                                    \
-    __asm__ __volatile__("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx" \
-                         : "=a"(res)                                          \
-                         : "0"(__NR_##name), "ri"((int)(arg1))                \
+#define __inline_syscall1(res, name, arg1)                                 \
+    __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+                         : "=a"(res)                                       \
+                         : "0"(__NR_##name), "ri"(arg1)                    \
                          : "memory");
 
 /// @brief Heart of the code that calls a system call with 2 parameters.
-#define __inline_syscall2(res, name, arg1, arg2)                                 \
-    __asm__ __volatile__("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx"    \
-                         : "=a"(res)                                             \
-                         : "0"(__NR_##name), "ri"((int)(arg1)), "c"((int)(arg2)) \
+#define __inline_syscall2(res, name, arg1, arg2)                           \
+    __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+                         : "=a"(res)                                       \
+                         : "0"(__NR_##name), "ri"(arg1), "c"(arg2)         \
                          : "memory");
 
 /// @brief Heart of the code that calls a system call with 3 parameters.
-#define __inline_syscall3(res, name, arg1, arg2, arg3)                            \
-    __asm__ __volatile__("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx"     \
-                         : "=a"(res)                                              \
-                         : "0"(__NR_##name), "ri"((int)(arg1)), "c"((int)(arg2)), \
-                           "d"((int)(arg3))                                       \
+#define __inline_syscall3(res, name, arg1, arg2, arg3)                        \
+    __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx"    \
+                         : "=a"(res)                                          \
+                         : "0"(__NR_##name), "ri"(arg1), "c"(arg2), "d"(arg3) \
                          : "memory");
 
 /// @brief Heart of the code that calls a system call with 4 parameters.
-#define __inline_syscall4(res, name, arg1, arg2, arg3, arg4)                      \
-    __asm__ __volatile__("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx"     \
-                         : "=a"(res)                                              \
-                         : "0"(__NR_##name), "ri"((int)(arg1)), "c"((int)(arg2)), \
-                           "d"((int)(arg3)), "S"((int)(arg4))                     \
+#define __inline_syscall4(res, name, arg1, arg2, arg3, arg4)                             \
+    __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx"               \
+                         : "=a"(res)                                                     \
+                         : "0"(__NR_##name), "ri"(arg1), "c"(arg2), "d"(arg3), "S"(arg4) \
                          : "memory");
 
 /// @brief Heart of the code that calls a system call with 5 parameters.
-#define __inline_syscall5(res, name, arg1, arg2, arg3, arg4, arg5)                \
-    __asm__ __volatile__("push %%ebx ; movl %2,%%ebx ; movl %1,%%eax ; "          \
-                         "int $0x80 ; pop %%ebx"                                  \
-                         : "=a"(res)                                              \
-                         : "i"(__NR_##name), "ri"((int)(arg1)), "c"((int)(arg2)), \
-                           "d"((int)(arg3)), "S"((int)(arg4)), "D"((int)(arg5))   \
+#define __inline_syscall5(res, name, arg1, arg2, arg3, arg4, arg5)                                  \
+    __asm__ __volatile__("push %%ebx; movl %2,%%ebx; movl %1,%%eax; "                               \
+                         "int $0x80; pop %%ebx"                                                     \
+                         : "=a"(res)                                                                \
+                         : "i"(__NR_##name), "ri"(arg1), "c"(arg2), "d"(arg3), "S"(arg4), "D"(arg5) \
                          : "memory");
 
 /// @brief System call with 0 parameters.
@@ -305,3 +313,19 @@
         __inline_syscall5(__res, name, arg1, arg2, arg3, arg4, arg5);                          \
         __syscall_return(type, __res);                                                         \
     }
+
+/// @brief System call with 5 parameters.
+#define _syscall6(type, name, type1, arg1, type2, arg2, type3, arg3, type4, arg4, type5, arg5, type6, arg6) \
+    type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5, type6 arg6)                       \
+    {                                                                                                       \
+        long __res;                                                                                         \
+        unsigned args[6] = { 0 };                                                                           \
+        args[0]          = (unsigned)arg1;                                                                  \
+        args[1]          = (unsigned)arg2;                                                                  \
+        args[2]          = (unsigned)arg3;                                                                  \
+        args[3]          = (unsigned)arg4;                                                                  \
+        args[4]          = (unsigned)arg5;                                                                  \
+        args[5]          = (unsigned)arg6;                                                                  \
+        __inline_syscall1(__res, name, args);                                                               \
+        __syscall_return(type, __res);                                                                      \
+    }

libc/inc/termios.h

@@ -1,6 +1,6 @@
 /// @file termios.h
 /// @brief Defines the termios functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/time.h

@@ -1,6 +1,6 @@
 /// @file time.h
 /// @brief Time-related functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/src/abort.c

@@ -1,15 +1,15 @@
 /// @file abort.c
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/unistd.h"
-#include "string.h"
 #include "signal.h"
 #include "stdio.h"
+#include "string.h"
 
-// Since there could be signal handlers listening for the abort, we
-//  need to keep track at which stage of the abort we are.
+/// @brief Since there could be signal handlers listening for the abort, we need
+/// to keep track at which stage of the abort we are.
 static int stage = 0;
 
 void abort(void)
@@ -28,7 +28,6 @@ void abort(void)
 
     /* Send signal which possibly calls a user handler.  */
     if (stage == 1) {
-
         // We must allow recursive calls of abort
         int save_stage = stage;
 

libc/src/assert.c

@@ -1,11 +1,11 @@
 /// @file assert.c
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "assert.h"
-#include "stdlib.h"
 #include "stdio.h"
+#include "stdlib.h"
 
 void __assert_fail(const char *assertion, const char *file, const char *function, unsigned int line)
 {

libc/src/crt0.s

@@ -0,0 +1,15 @@
+.extern main
+.extern __libc_start_main
+.global _start
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+_start:                      # _start is the entry point known to the linker
+    mov $0, %ebp            # Set ebp to 0 as x86 programs require
+    push $main
+    call __libc_start_main  # Call the libc initialization function.
+    mov %eax, %ebx          # Move `main` return value to ebx.
+    mov $1, %eax            # Call the `exit` function by using `int 80` (i.e., a system call)
+    int $0x80

libc/src/ctype.c

@@ -1,6 +1,6 @@
 /// @file ctype.c
 /// @brief Functions related to character handling.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "ctype.h"

libc/src/debug.c

@@ -1,108 +0,0 @@
-/// @file   debug.c
-/// @brief  Debugging primitives.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
-/// See LICENSE.md for details.
-
-#include <debug.h>
-
-#include <stddef.h>
-#include <io/port_io.h>
-#include <stdio.h>
-#include <string.h>
-#include <sys/bitops.h>
-#include <math.h>
-
-/// Serial port for QEMU.
-#define SERIAL_COM1 (0x03F8)
-
-#define FG_RESET "\033[0m" ///< ANSI code for resetting.
-
-void dbg_putchar(char c)
-{
-    outportb(SERIAL_COM1, (uint8_t)c);
-}
-
-void dbg_puts(const char *s)
-{
-    while ((*s) != 0)
-        dbg_putchar(*s++);
-}
-
-static inline void __debug_print_header(const char *file, const char *fun, int line)
-{
-    static char tmp_prefix[BUFSIZ], final_prefix[BUFSIZ];
-    dbg_puts(FG_RESET);
-    dbg_puts("[ LB |");
-    sprintf(tmp_prefix, "%s:%d", file, line);
-    sprintf(final_prefix, " %-20s ", tmp_prefix);
-    dbg_puts(final_prefix);
-#if 0
-    dbg_putchar('|');
-    sprintf(final_prefix, " %-25s ]", fun);
-    dbg_puts(final_prefix);
-#else
-    dbg_putchar(']');
-#endif
-}
-
-void dbg_printf(const char *file, const char *fun, int line, const char *format, ...)
-{
-    // Define a buffer for the formatted string.
-    static char formatted[BUFSIZ];
-    static short new_line = 1;
-
-    // Stage 1: FORMAT
-    if (strlen(format) >= BUFSIZ)
-        return;
-
-    // Start variabile argument's list.
-    va_list ap;
-    va_start(ap, format);
-    // Format the message.
-    vsprintf(formatted, format, ap);
-    // End the list of arguments.
-    va_end(ap);
-
-    // Stage 2: SEND
-    if (new_line) {
-        __debug_print_header(file, fun, line);
-        new_line = 0;
-    }
-    for (size_t it = 0; (formatted[it] != 0) && (it < BUFSIZ); ++it) {
-        dbg_putchar(formatted[it]);
-        if (formatted[it] != '\n') {
-            continue;
-        }
-        if ((it + 1) >= BUFSIZ) {
-            continue;
-        }
-        if (formatted[it + 1] == 0) {
-            new_line = 1;
-        } else {
-            __debug_print_header(file, fun, line);
-        }
-    }
-}
-
-const char *to_human_size(unsigned long bytes)
-{
-    static char output[200];
-    const char *suffix[] = { "B", "KB", "MB", "GB", "TB" };
-    char length          = sizeof(suffix) / sizeof(suffix[0]);
-    int i                = 0;
-    double dblBytes      = bytes;
-    if (bytes > 1024) {
-        for (i = 0; (bytes / 1024) > 0 && i < length - 1; i++, bytes /= 1024)
-            dblBytes = bytes / 1024.0;
-    }
-    sprintf(output, "%.03lf %2s", dblBytes, suffix[i]);
-    return output;
-}
-
-const char *dec_to_binary(unsigned long value, unsigned length)
-{
-    static char buffer[33];
-    for (int i = 0, j = 32 - min(max(0, length), 32); j < 32; ++i, ++j)
-        buffer[i] = bit_check(value, 31 - j) ? '1' : '0';
-    return buffer;
-}

libc/src/fcvt.c

@@ -1,6 +1,6 @@
 /// @file fcvt.c
 /// @brief Define the functions required to turn double values into a string.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "fcvt.h"
@@ -83,8 +83,9 @@ static void cvt(double arg, int ndigits, int *decpt, int *sign, char *buf, unsig
             *p1 = '1';
             (*decpt)++;
             if (eflag == 0) {
-                if (p > buf)
+                if (p > buf) {
                     *p = '0';
+                }
                 p++;
             }
         }

libc/src/grp.c

@@ -1,55 +1,72 @@
 /// @file grp.c
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "grp.h"
-#include "sys/unistd.h"
-#include "sys/errno.h"
 #include "assert.h"
-#include "string.h"
-#include "stdio.h"
-#include "debug.h"
 #include "fcntl.h"
+#include "io/debug.h"
+#include "stdio.h"
+#include "string.h"
+#include "sys/errno.h"
+#include "sys/unistd.h"
 
+/// Holds the file descriptor while we are working with `/etc/group`.
 static int __fd = -1;
 
+/// @brief It parses the line (as string) and saves its content inside the
+/// group_t structure.
+/// @param grp the struct where we store the information.
+/// @param buf the line from which we extract the information.
 static inline void __parse_line(group_t *grp, char *buf)
 {
     assert(grp && "Received null grp!");
     char *token;
     // Parse the group name.
-    if ((token = strtok(buf, ":")) != NULL)
+    token = strtok(buf, ":");
+    if (token != NULL) {
         grp->gr_name = token;
+    }
     // Parse the group passwd.
-    if ((token = strtok(NULL, ":")) != NULL)
+    token = strtok(NULL, ":");
+    if (token != NULL) {
         grp->gr_passwd = token;
+    }
     // Parse the group id.
-    if ((token = strtok(NULL, ":")) != NULL)
+    token = strtok(NULL, ":");
+    if (token != NULL) {
         grp->gr_gid = atoi(token);
-
+    }
     size_t found_users = 0;
     while ((token = strtok(NULL, ",\n\0")) != NULL && found_users < MAX_MEMBERS_PER_GROUP) {
         grp->gr_mem[found_users] = token;
         found_users += 1;
     }
-
     // Null terminate array
     grp->gr_mem[found_users] = "\0";
 }
 
-static inline char *__search_entry(int fd, char *buf, int buflen, const char *name, gid_t gid)
+/// @brief Searches an entry in `/etc/group`.
+/// @param fd the file descriptor pointing to `/etc/group`.
+/// @param buf the buffer we are going to use to search the entry.
+/// @param buflen the length of the buffer.
+/// @param name the name we are looking for.
+/// @param gid the group id we must match.
+/// @return 1 on success, 0 on failure.
+static inline int __search_entry(int fd, char *buf, size_t buflen, const char *name, gid_t gid)
 {
     int ret;
     char c;
     int pos = 0;
     while ((ret = read(fd, &c, 1U))) {
         // Skip carriage return.
-        if (c == '\r')
+        if (c == '\r') {
             continue;
+        }
         if (pos >= buflen) {
             errno = ERANGE;
-            return NULL;
+            return 0;
         }
         // If we have found a newline or the EOF, parse the entry.
         if ((c == '\n') || (ret == EOF)) {
@@ -57,8 +74,9 @@ static inline char *__search_entry(int fd, char *buf, int buflen, const char *na
             buf[pos] = 0;
             // Check the entry.
             if (name) {
-                if (strncmp(buf, name, strlen(name)) == 0)
-                    return buf;
+                if (strncmp(buf, name, strlen(name)) == 0) {
+                    return 1;
+                }
             } else {
                 int gid_start = -1, col_count = 0;
                 for (int i = 0; i < pos; ++i) {
@@ -73,21 +91,23 @@ static inline char *__search_entry(int fd, char *buf, int buflen, const char *na
                     // Parse the gid.
                     int found_gid = atoi(&buf[gid_start]);
                     // Check the gid.
-                    if (found_gid == gid)
-                        return buf;
+                    if (found_gid == gid) {
+                        return 1;
+                    }
                 }
             }
             // Reset the index.
             pos = 0;
             // If we have reached the EOF stop.
-            if (ret == EOF)
+            if (ret == EOF) {
                 break;
+            }
         } else {
             buf[pos++] = c;
         }
     }
     errno = ENOENT;
-    return NULL;
+    return 0;
 }
 
 group_t *getgrgid(gid_t gid)
@@ -96,23 +116,26 @@ group_t *getgrgid(gid_t gid)
     static char buffer[BUFSIZ];
 
     group_t *result;
-    if (!getgrgid_r(gid, &grp, buffer, BUFSIZ, &result))
+    if (!getgrgid_r(gid, &grp, buffer, BUFSIZ, &result)) {
         return NULL;
+    }
 
     return &grp;
 }
 
 group_t *getgrnam(const char *name)
 {
-    if (name == NULL)
+    if (name == NULL) {
         return NULL;
+    }
 
     static group_t grp;
     static char buffer[BUFSIZ];
 
     group_t *result;
-    if (!getgrnam_r(name, &grp, buffer, BUFSIZ, &result))
+    if (!getgrnam_r(name, &grp, buffer, BUFSIZ, &result)) {
         return NULL;
+    }
 
     return &grp;
 }
@@ -126,12 +149,11 @@ int getgrgid_r(gid_t gid, group_t *group, char *buf, size_t buflen, group_t **re
         return 0;
     }
 
-    char *entry = __search_entry(fd, buf, buflen, NULL, gid);
-    if (entry != NULL) {
+    if (__search_entry(fd, buf, buflen, NULL, gid)) {
         // Close the file.
         close(fd);
         // Parse the line.
-        __parse_line(group, entry);
+        __parse_line(group, buf);
         // Return success.
         return 1;
     }
@@ -151,12 +173,11 @@ int getgrnam_r(const char *name, group_t *group, char *buf, size_t buflen, group
         return 0;
     }
 
-    char *entry = __search_entry(fd, buf, buflen, name, 0);
-    if (entry != NULL) {
+    if (__search_entry(fd, buf, buflen, name, 0)) {
         // Close the file.
         close(fd);
         // Parse the line.
-        __parse_line(group, entry);
+        __parse_line(group, buf);
         // Return success.
         return 1;
     }
@@ -187,8 +208,9 @@ group_t *getgrent(void)
     static char buffer[BUFSIZ];
     while ((ret = read(__fd, &c, 1U))) {
         // Skip carriage return.
-        if (c == '\r')
+        if (c == '\r') {
             continue;
+        }
 
         if (pos >= BUFSIZ) {
             errno = ERANGE;
@@ -208,8 +230,9 @@ group_t *getgrent(void)
             }
 
             // If we have reached the EOF stop.
-            if (ret == EOF)
+            if (ret == EOF) {
                 break;
+            }
 
         } else {
             buffer[pos++] = c;
@@ -231,4 +254,4 @@ void setgrent(void)
 {
     //pr_debug("Resetting pointer to beginning of group file\n");
     lseek(__fd, 0, SEEK_SET);
-}
+}

libc/src/io/debug.c

@@ -0,0 +1,188 @@
+/// @file   debug.c
+/// @brief  Debugging primitives.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#include "io/debug.h"
+#include "io/ansi_colors.h"
+#include "io/port_io.h"
+#include "math.h"
+#include "stdio.h"
+#include "string.h"
+#include "sys/bitops.h"
+
+/// Serial port for QEMU.
+#define SERIAL_COM1 (0x03F8)
+/// Determines the log level.
+static int max_log_level = LOGLEVEL_DEBUG;
+
+void dbg_putchar(char c)
+{
+    outportb(SERIAL_COM1, (unsigned char)c);
+}
+
+void dbg_puts(const char *s)
+{
+    while ((*s) != 0) {
+        dbg_putchar(*s++);
+    }
+}
+
+static inline void __debug_print_header(const char *file, const char *fun, int line, short log_level, char *header)
+{
+    // "EMERG  ", "ALERT  ", "CRIT   ", "ERR    ", "WARNING", "NOTICE ", "INFO   ", "DEBUG  ", "DEFAULT",
+    static const char *log_level_label[] = { " EM ", " AL ", " CR ", " ER ", " WR ", " NT ", " IN ", " DB ", " DF " };
+    static const char *log_level_color[] = {
+        FG_RED_BRIGHT,    // "EMERG  "
+        FG_RED_BRIGHT,    // "ALERT  "
+        FG_RED,           // "CRIT   "
+        FG_RED,           // "ERR    "
+        FG_YELLOW_BRIGHT, // "WARNING"
+        FG_RESET,         // "NOTICE "
+        FG_CYAN,          // "INFO   "
+        FG_YELLOW,        // "DEBUG  "
+        FG_RESET          // "DEFAULT"
+    };
+    static char tmp_prefix[BUFSIZ], final_prefix[BUFSIZ];
+    // Check the log level.
+    if ((log_level < LOGLEVEL_EMERG) || (log_level > LOGLEVEL_DEBUG)) {
+        // Set it to default.
+        log_level = 8;
+    }
+    // Set the color.
+    dbg_puts(log_level_color[log_level]);
+    dbg_putchar('[');
+    // Set the label.
+    dbg_puts(log_level_label[log_level]);
+    dbg_putchar('|');
+    // Print the file and line.
+    sprintf(tmp_prefix, "%s:%d", file, line);
+    // Print the message.
+    sprintf(final_prefix, " %-20s ", tmp_prefix);
+    // Print the actual message.
+    dbg_puts(final_prefix);
+#if 0
+    dbg_putchar('|');
+    sprintf(final_prefix, " %-25s ]", fun);
+    dbg_puts(final_prefix);
+#else
+    dbg_putchar(']');
+#endif
+    dbg_putchar(' ');
+    if (header) {
+        dbg_puts(header);
+        dbg_putchar(' ');
+    }
+}
+
+void set_log_level(int level)
+{
+    if ((level >= LOGLEVEL_EMERG) && (level <= LOGLEVEL_DEBUG)) {
+        max_log_level = level;
+    }
+}
+
+int get_log_level(void)
+{
+    return max_log_level;
+}
+
+void dbg_printf(const char *file, const char *fun, int line, char *header, short log_level, const char *format, ...)
+{
+    // Define a buffer for the formatted string.
+    static char formatted[BUFSIZ];
+    static short new_line = 1;
+
+    // Stage 1: FORMAT
+    if (strlen(format) >= BUFSIZ) {
+        return;
+    }
+
+    // Start variabile argument's list.
+    va_list ap;
+    va_start(ap, format);
+    // Format the message.
+    vsprintf(formatted, format, ap);
+    // End the list of arguments.
+    va_end(ap);
+
+    // Stage 2: SEND
+    if (new_line) {
+        __debug_print_header(file, fun, line, log_level, header);
+        new_line = 0;
+    }
+    for (int it = 0; (formatted[it] != 0) && (it < BUFSIZ); ++it) {
+        dbg_putchar(formatted[it]);
+        if (formatted[it] != '\n') {
+            continue;
+        }
+        if ((it + 1) >= BUFSIZ) {
+            continue;
+        }
+        if (formatted[it + 1] == 0) {
+            new_line = 1;
+        } else {
+            __debug_print_header(file, fun, line, log_level, header);
+        }
+    }
+}
+
+const char *to_human_size(unsigned long bytes)
+{
+    static char output[200];
+    const char *suffix[] = { "B", "KB", "MB", "GB", "TB" };
+    char length          = sizeof(suffix) / sizeof(suffix[0]);
+    int i                = 0;
+    double dblBytes      = bytes;
+    if (bytes > 1024) {
+        for (i = 0; (bytes / 1024) > 0 && i < length - 1; i++, bytes /= 1024) {
+            dblBytes = bytes / 1024.0;
+        }
+    }
+    sprintf(output, "%.02lf %2s", dblBytes, suffix[i]);
+    return output;
+}
+
+const char *dec_to_binary(unsigned long value, unsigned length)
+{
+    static char buffer[33];
+    // Adjust the length.
+    length = min(max(0, length), 32U);
+    // Build the binary.
+    for (unsigned i = 0, j = 32U - length; j < 32U; ++i, ++j) {
+        buffer[i] = bit_check(value, 31 - j) ? '1' : '0';
+    }
+    // Close the string.
+    buffer[length] = 0;
+    return buffer;
+}
+
+#ifdef __KERNEL__
+
+#include "kernel.h"
+
+void dbg_print_regs(pt_regs *frame)
+{
+    pr_debug("Interrupt stack frame:\n");
+    pr_debug("GS     = 0x%-04x\n", frame->gs);
+    pr_debug("FS     = 0x%-04x\n", frame->fs);
+    pr_debug("ES     = 0x%-04x\n", frame->es);
+    pr_debug("DS     = 0x%-04x\n", frame->ds);
+    pr_debug("EDI    = 0x%-09x\n", frame->edi);
+    pr_debug("ESI    = 0x%-09x\n", frame->esi);
+    pr_debug("EBP    = 0x%-09x\n", frame->ebp);
+    pr_debug("ESP    = 0x%-09x\n", frame->esp);
+    pr_debug("EBX    = 0x%-09x\n", frame->ebx);
+    pr_debug("EDX    = 0x%-09x\n", frame->edx);
+    pr_debug("ECX    = 0x%-09x\n", frame->ecx);
+    pr_debug("EAX    = 0x%-09x\n", frame->eax);
+    pr_debug("INT_NO = %-9d\n", frame->int_no);
+    pr_debug("ERR_CD = %-9d\n", frame->err_code);
+    pr_debug("EIP    = 0x%-09x\n", frame->eip);
+    pr_debug("CS     = 0x%-04x\n", frame->cs);
+    pr_debug("EFLAGS = 0x%-09x\n", frame->eflags);
+    pr_debug("UESP   = 0x%-09x\n", frame->useresp);
+    pr_debug("SS     = 0x%-04x\n", frame->ss);
+}
+
+#endif

libc/src/io/mm_io.c

@@ -1,36 +1,36 @@
 /// @file mm_io.c
 /// @brief Memory Mapped IO functions implementation.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "io/mm_io.h"
 
-uint8_t in_memb(uint32_t addr)
+inline uint8_t in_memb(uint32_t addr)
 {
     return *((uint8_t *) (addr));
 }
 
-uint16_t in_mems(uint32_t addr)
+inline uint16_t in_mems(uint32_t addr)
 {
     return *((uint16_t *) (addr));
 }
 
-uint32_t in_meml(uint32_t addr)
+inline uint32_t in_meml(uint32_t addr)
 {
     return *((uint32_t *) (addr));
 }
 
-void out_memb(uint32_t addr, uint8_t value)
+inline void out_memb(uint32_t addr, uint8_t value)
 {
     (*((uint8_t *) (addr))) = (value);
 }
 
-void out_mems(uint32_t addr, uint16_t value)
+inline void out_mems(uint32_t addr, uint16_t value)
 {
     (*((uint16_t *) (addr))) = (value);
 }
 
-void out_meml(uint32_t addr, uint32_t value)
+inline void out_meml(uint32_t addr, uint32_t value)
 {
     (*((uint32_t *) (addr))) = (value);
 }

libc/src/io/port_io.c

@@ -1,58 +0,0 @@
-/// @file port_io.c
-/// @brief Byte I/O on ports prototypes.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
-/// See LICENSE.md for details.
-
-#include "io/port_io.h"
-
-inline uint8_t inportb(uint16_t port)
-{
-    unsigned char data = 0;
-    __asm__ __volatile__("inb %%dx, %%al" : "=a"(data) : "d"(port));
-
-    return data;
-}
-
-inline uint16_t inports(uint16_t port)
-{
-    uint16_t rv;
-    __asm__ __volatile__("inw %1, %0" : "=a"(rv) : "dN"(port));
-
-    return rv;
-}
-
-void inportsm(uint16_t port, uint8_t *data, unsigned long size)
-{
-    __asm__ __volatile__("rep insw"
-                         : "+D"(data), "+c"(size)
-                         : "d"(port)
-                         : "memory");
-}
-
-inline uint32_t inportl(uint16_t port)
-{
-    uint32_t rv;
-    __asm__ __volatile__("inl %%dx, %%eax" : "=a"(rv) : "dN"(port));
-
-    return rv;
-}
-
-inline void outportb(uint16_t port, uint8_t data)
-{
-    __asm__ __volatile__("outb %%al, %%dx" ::"a"(data), "d"(port));
-}
-
-inline void outports(uint16_t port, uint16_t data)
-{
-    __asm__ __volatile__("outw %1, %0" : : "dN"(port), "a"(data));
-}
-
-void outportsm(uint16_t port, uint8_t *data, uint16_t size)
-{
-    asm volatile("rep outsw" : "+S"(data), "+c"(size) : "d"(port));
-}
-
-inline void outportl(uint16_t port, uint32_t data)
-{
-    __asm__ __volatile__("outl %%eax, %%dx" : : "dN"(port), "a"(data));
-}

libc/src/ipc/ipc.c

@@ -1,35 +0,0 @@
-/// @file ipc.c
-/// @brief Inter-Process Communication (IPC) system call implementation.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
-/// See LICENSE.md for details.
-
-#include "sys/unistd.h"
-#include "system/syscall_types.h"
-#include "sys/errno.h"
-#include "stddef.h"
-#include "ipc/sem.h"
-#include "ipc/shm.h"
-#include "ipc/msg.h"
-
-_syscall3(void *, shmat, int, shmid, const void *, shmaddr, int, shmflg)
-
-_syscall3(long, shmget, key_t, key, size_t, size, int, flag)
-
-_syscall1(long, shmdt, const void *, shmaddr)
-
-_syscall3(long, shmctl, int, shmid, int, cmd, struct shmid_ds *, buf)
-
-_syscall3(long, semget, key_t, key, int, nsems, int, semflg)
-
-_syscall3(long, semop, int, semid, struct sembuf *, sops, unsigned, nsops)
-
-_syscall4(long, semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
-
-_syscall2(long, msgget, key_t, key, int, msgflg)
-
-_syscall4(long, msgsnd, int, msqid, struct msgbuf *, msgp, size_t, msgsz, int, msgflg)
-
-_syscall5(long, msgrcv, int, msqid, struct msgbuf *, msgp, size_t, msgsz, long, msgtyp, int, msgflg)
-
-_syscall3(long, msgctl, int, msqid, int, cmd, struct msqid_ds *, buf)
-

libc/src/libc_start.c

@@ -1,14 +1,14 @@
 /// @file libc_start.c
 /// @brief Contains the programs initialization procedure.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/unistd.h"
+#include "assert.h"
 #include "stdlib.h"
 #include "string.h"
-#include "assert.h"
-#include "system/syscall_types.h"
 #include "sys/errno.h"
+#include "system/syscall_types.h"
 
 /// @brief Reference to the `environ` variable in `setenv.c`.
 extern char **environ;

libc/src/libgen.c

@@ -1,85 +1,64 @@
 /// @file libgen.c
 /// @brief String routines.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
+#include "libgen.h"
+#include "io/debug.h"
+#include "limits.h"
+#include "string.h"
 #include <assert.h>
 #include <stdlib.h>
 #include <sys/unistd.h>
-#include "libgen.h"
-#include "string.h"
-#include "limits.h"
 
-int parse_path(char *out, char **cur, char sep, size_t max)
+int dirname(const char *path, char *buffer, size_t buflen)
 {
-    if (**cur == '\0') {
+    if ((path == NULL) || (buffer == NULL) || (buflen == 0)) {
         return 0;
     }
-
-    *out++ = **cur;
-    ++*cur;
-    --max;
-
-    while ((max > 0) && (**cur != '\0') && (**cur != sep)) {
-        *out++ = **cur;
-        ++*cur;
-        --max;
+    // Search for the last slash.
+    const char *last_slash = NULL;
+    for (const char *it = path; *it; it++) {
+        if ((*it) == '/') {
+            last_slash = it;
+        }
+    }
+    // If we were able to find a slash, and the slash is not in the first
+    // position, copy the substring.
+    if (last_slash) {
+        // Get the length of the substring, if the last slash is at the beginning,
+        // add 1.
+        size_t dirlen = last_slash - path + (last_slash == path);
+        // Check if the path will fit inside the buffer.
+        if (dirlen >= buflen) {
+            return 0;
+        }
+        // Copy the substring.
+        strncpy(buffer, path, dirlen);
+        // Close the buffer.
+        buffer[dirlen] = 0;
+    } else {
+        strcpy(buffer, ".");
     }
-
-    *out = '\0';
-
     return 1;
 }
 
-char *dirname(const char *path)
+const char *basename(const char *path)
 {
-    static char s[PATH_MAX];
-
-    static char dot[2] = ".";
-
-    // Check the input path.
-    if (path == NULL) {
-        return dot;
+    // Search for the last slash.
+    const char *last_slash = NULL;
+    for (const char *it = path; *it; it++) {
+        if ((*it) == '/') {
+            last_slash = it;
+        }
     }
-
-    // Copy the path to the support string.
-    strcpy(s, path);
-
-    // Get the last occurrence of '/'.
-    char *last_slash = strrchr(s, '/');
-
-    if (last_slash == s) {
-        // If the slash is acutally the first character of the string, move the
-        // pointer to the last slash after it.
-        ++last_slash;
-    } else if ((last_slash != NULL) && (last_slash[1] == '\0')) {
-        // If the slash is the last character, we need to search before it.
-        last_slash = memchr(s, '/', last_slash - s);
-    }
-
-    if (last_slash != NULL) {
-        // If we have found it, close the string.
-        last_slash[0] = '\0';
-    } else {
-        // Otherwise, return '.'.
-        return dot;
-    }
-
-    return s;
+    return last_slash ? last_slash + 1 : path;
 }
 
-char *basename(const char *path)
-{
-    char *p = strrchr(path, '/');
-
-    return p ? p + 1 : (char *)path;
-}
-
-char *realpath(const char *path, char *resolved)
+char *realpath(const char *path, char *buffer, size_t buflen)
 {
     assert(path && "Provided null path.");
-    if (resolved == NULL)
-        resolved = malloc(sizeof(char) * PATH_MAX);
+    assert(buffer && "Provided null buffer.");
     char abspath[PATH_MAX];
     // Initialize the absolute path.
     memset(abspath, '\0', PATH_MAX);
@@ -119,22 +98,27 @@ char *realpath(const char *path, char *resolved)
         // Go to previous directory if /../ is found
         else if (!strncmp("/../", abspath + absidx, 4)) {
             // Go to a valid path character (pathidx points to the next one)
-            if (pathidx)
+            if (pathidx) {
                 pathidx--;
-            while (pathidx && resolved[pathidx] != '/') {
+            }
+            while (pathidx && buffer[pathidx] != '/') {
                 pathidx--;
             }
             absidx += 3;
         } else if (!strncmp("/./", abspath + absidx, 3)) {
             absidx += 2;
         } else {
-            resolved[pathidx++] = abspath[absidx++];
+            if ((pathidx + 1) >= buflen) {
+                return NULL;
+            }
+            buffer[pathidx++] = abspath[absidx++];
         }
     }
     // Remove the last /
-    if (pathidx > 1)
-        resolved[pathidx - 1] = '\0';
-    else
-        resolved[1] = '\0';
-    return resolved;
-}
+    if (pathidx > 1) {
+        buffer[pathidx - 1] = '\0';
+    } else {
+        buffer[1] = '\0';
+    }
+    return buffer;
+}

libc/src/math.c

@@ -1,6 +1,6 @@
 /// @file math.c
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "math.h"
@@ -18,26 +18,30 @@ double round(double x)
 double floor(double x)
 {
     if (x > -1.0 && x < 1.0) {
-        if (x >= 0)
+        if (x >= 0) {
             return 0.0;
+        }
         return -1.0;
     }
     int i = (int)x;
-    if (x < 0)
+    if (x < 0) {
         return (double)(i - 1);
+    }
     return (double)i;
 }
 
 double ceil(double x)
 {
     if (x > -1.0 && x < 1.0) {
-        if (x <= 0)
+        if (x <= 0) {
             return 0.0;
+        }
         return 1.0;
     }
     int i = (int)x;
-    if (x > 0)
+    if (x > 0) {
         return (double)(i + 1);
+    }
     return (double)i;
 }
 
@@ -145,8 +149,9 @@ double ln(double x)
 double logx(double x, double y)
 {
     // Base may not equal 1 or be negative.
-    if (y == 1.f || y < 0.f || ln(y) == 0.f)
+    if (y == 1.f || y < 0.f || ln(y) == 0.f) {
         return 0.f;
+    }
     return ln(x) / ln(y);
 }
 

libc/src/pwd.c

@@ -1,89 +1,73 @@
 /// @file pwd.c
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "pwd.h"
-#include "sys/unistd.h"
-#include "sys/errno.h"
 #include "assert.h"
-#include "string.h"
-#include "stdio.h"
 #include "fcntl.h"
-#include "debug.h"
+#include "io/debug.h"
+#include "readline.h"
+#include "stdio.h"
+#include "string.h"
+#include "sys/errno.h"
+#include "sys/unistd.h"
 
+/// @brief Parses the input buffer and fills pwd with its details.
+/// @param pwd the structure we need to fill.
+/// @param buf the buffer from which we extract the information.
 static inline void __parse_line(passwd_t *pwd, char *buf)
 {
     assert(pwd && "Received null pwd!");
     char *token, *ch;
     // Parse the username.
-    if ((token = strtok(buf, ":")) != NULL)
+    if ((token = strtok(buf, ":")) != NULL) {
         pwd->pw_name = token;
+    }
     // Parse the password.
-    if ((token = strtok(NULL, ":")) != NULL)
+    if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_passwd = token;
+    }
     // Parse the user ID.
-    if ((token = strtok(NULL, ":")) != NULL)
+    if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_uid = atoi(token);
+    }
     // Parse the group ID.
-    if ((token = strtok(NULL, ":")) != NULL)
+    if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_gid = atoi(token);
+    }
     // Parse the user information.
-    if ((token = strtok(NULL, ":")) != NULL)
+    if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_gecos = token;
+    }
     // Parse the dir.
-    if ((token = strtok(NULL, ":")) != NULL)
+    if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_dir = token;
+    }
     // Parse the shell.
     if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_shell = token;
         // Find carriege return.
-        if ((ch = strchr(pwd->pw_shell, '\r')))
+        if ((ch = strchr(pwd->pw_shell, '\r'))) {
             *ch = 0;
+        }
         // Find newline.
-        if ((ch = strchr(pwd->pw_shell, '\n')))
+        if ((ch = strchr(pwd->pw_shell, '\n'))) {
             *ch = 0;
-    }
-}
-
-/// @brief Reads a line from the file.
-/// @param fd the file descriptor.
-/// @param buffer the buffer where we place the line.
-/// @param buflen the length of the buffer.
-/// @return the amount we read.
-ssize_t __readline(int fd, char *buffer, size_t buflen)
-{
-    memset(buffer, 0, buflen);
-    long num_read = read(fd, buffer, buflen);
-    if (num_read == 0) {
-        return 0;
-    }
-    char *newline = strchr(buffer, '\n');
-    if (newline == NULL) {
-        newline = strchr(buffer, EOF);
-        if (newline == NULL) {
-            newline = strchr(buffer, 0);
-            if (newline == NULL) {
-                return 0;
-            }
         }
     }
-    long newline_len = (int)(newline - buffer);
-    if (newline_len <= 0) {
-        return 0;
-    }
-    buffer[newline_len] = 0;
-    long rollback       = newline_len - num_read + 1;
-    if (rollback > 1) {
-        return 0;
-    }
-    lseek(fd, rollback, SEEK_CUR);
-    return newline_len;
 }
 
+/// @brief Searches for the given entry inside the buffer.
+/// @param fd the file descriptor of the file.
+/// @param buffer the support buffer we use to read the file.
+/// @param buflen the length of the support buffer.
+/// @param name the username we are looking for.
+/// @param uid the user-id of the user we are looking for.
+/// @return the buffer itself if we have found the entry, NULL otherwise.
 static inline char *__search_entry(int fd, char *buffer, int buflen, const char *name, uid_t uid)
 {
-    while (__readline(fd, buffer, buflen)) {
+    while (readline(fd, buffer, buflen, NULL) != 0) {
         if (name != NULL) {
             char *name_end = strchr(buffer, ':');
             if (name_end) {
@@ -96,17 +80,20 @@ static inline char *__search_entry(int fd, char *buffer, int buflen, const char
         } else {
             // Name
             char *ptr = strchr(buffer, ':');
-            if (ptr == NULL)
+            if (ptr == NULL) {
                 continue;
+            }
             // Password
             ++ptr;
             char *uid_start = strchr(ptr, ':');
-            if (uid_start == NULL)
+            if (uid_start == NULL) {
                 continue;
+            }
             ++uid_start;
             ptr = strchr(uid_start, ':');
-            if (ptr == NULL)
+            if (ptr == NULL) {
                 continue;
+            }
             *ptr = '\0';
             // Parse the uid.
             int found_uid = atoi(uid_start);
@@ -122,13 +109,15 @@ static inline char *__search_entry(int fd, char *buffer, int buflen, const char
 
 passwd_t *getpwnam(const char *name)
 {
-    if (name == NULL)
+    if (name == NULL) {
         return NULL;
+    }
     static passwd_t pwd;
     static char buffer[BUFSIZ];
     passwd_t *result;
-    if (!getpwnam_r(name, &pwd, buffer, BUFSIZ, &result))
+    if (!getpwnam_r(name, &pwd, buffer, BUFSIZ, &result)) {
         return NULL;
+    }
     return &pwd;
 }
 
@@ -137,15 +126,17 @@ passwd_t *getpwuid(uid_t uid)
     static passwd_t pwd;
     static char buffer[BUFSIZ];
     passwd_t *result;
-    if (!getpwuid_r(uid, &pwd, buffer, BUFSIZ, &result))
+    if (!getpwuid_r(uid, &pwd, buffer, BUFSIZ, &result)) {
         return NULL;
+    }
     return &pwd;
 }
 
 int getpwnam_r(const char *name, passwd_t *pwd, char *buf, size_t buflen, passwd_t **result)
 {
-    if (name == NULL)
+    if (name == NULL) {
         return 0;
+    }
     int fd = open("/etc/passwd", O_RDONLY, 0);
     if (fd == -1) {
         pr_debug("Cannot open `/etc/passwd`\n");

libc/src/readline.c

@@ -0,0 +1,57 @@
+/// @file readline.c
+/// @author Enrico Fraccaroli (enry.frak@gmail.com)
+/// @brief
+/// @version 0.1
+/// @date 2023-08-30
+///
+/// @copyright Copyright (c) 2023
+///
+
+#include "readline.h"
+
+#include "stdio.h"
+#include "string.h"
+#include "sys/unistd.h"
+
+int readline(int fd, char *buffer, size_t buflen, ssize_t *read_len)
+{
+    ssize_t length, rollback, num_read;
+    memset(buffer, 0, buflen);
+    unsigned char found_newline = 1;
+    // Read from the file.
+    num_read = read(fd, buffer, buflen);
+    if (num_read == 0) {
+        return 0;
+    }
+    // Search for termination character.
+    char *newline = strchr(buffer, '\n');
+    if (newline == NULL) {
+        found_newline = 0;
+        newline       = strchr(buffer, EOF);
+        if (newline == NULL) {
+            newline = strchr(buffer, 0);
+            if (newline == NULL) {
+                return 0;
+            }
+        }
+    }
+    // Compute the length of the string.
+    length = (newline - buffer);
+    if (length <= 0) {
+        return 0;
+    }
+    // Close the string.
+    buffer[length] = 0;
+    // Compute how much we need to rollback.
+    rollback = length - num_read + 1;
+    if (rollback > 1) {
+        return 0;
+    }
+    // Rollback the reading position in the file.
+    lseek(fd, rollback, SEEK_CUR);
+    // Set how much we were able to read from the file.
+    if (read_len) {
+        *read_len = length;
+    }
+    return (found_newline) ? 1 : -1;
+}

libc/src/sched.c

@@ -1,11 +1,11 @@
 /// @file sched.c
 /// @brief Function for managing scheduler.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "system/syscall_types.h"
-#include "sys/errno.h"
 #include "sched.h"
+#include "sys/errno.h"
 
 _syscall2(int, sched_setparam, pid_t, pid, const sched_param_t *, param)
 

libc/src/setenv.c

@@ -1,30 +1,39 @@
 /// @file setenv.c
 /// @brief Defines the functions used to manipulate the environmental variables.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include <assert.h>
 #include "sys/errno.h"
-#include "string.h"
 #include "stdlib.h"
+#include "string.h"
+#include <assert.h>
 
 char **environ;
 
-static char **__environ      = NULL;
+/// @brief Global environ list.
+static char **__environ = NULL;
+/// @brief Size of the global environ list.
 static size_t __environ_size = 0;
 
+/// @brief Finds the entry in the environ.
+/// @param name the name of the entry we are looking for.
+/// @param name_len the length of the name we received.
+/// @return the index of the entry, or -1 if we did not find it.
 static inline int __find_entry(const char *name, const size_t name_len)
 {
     if (environ) {
         int index = 0;
-        for (char **ptr = environ; *ptr; ++ptr, ++index)
-            if (!strncmp((*ptr), name, name_len) && (*ptr)[name_len] == '=')
+        for (char **ptr = environ; *ptr; ++ptr, ++index) {
+            if (!strncmp((*ptr), name, name_len) && (*ptr)[name_len] == '=') {
                 return index;
+            }
+        }
     }
     return -1;
 }
 
-static void __clone_environ()
+/// @brief Makes a clone of the current environ.
+static void __clone_environ(void)
 {
     if (environ) {
         // Count the number of variables.
@@ -91,8 +100,9 @@ int setenv(const char *name, const char *value, int replace)
         environ = __environ = new_environ;
     }
     // Free the previous entry.
-    if (environ[index])
+    if (environ[index]) {
         free(environ[index]);
+    }
     // Allocate the new entry.
     environ[index] = malloc(total_len);
     // Memcopy because we do not want the null terminating character.
@@ -122,8 +132,9 @@ int unsetenv(const char *name)
         if (!strncmp(*ep, name, len) && (*ep)[len] == '=') {
             /* Found it.  Remove this pointer by moving later ones back.  */
             char **dp = ep;
-            do dp[0] = dp[1];
-            while (*dp++);
+            do {
+                dp[0] = dp[1];
+            } while (*dp++);
             /* Continue the loop in case NAME appears again.  */
         } else {
             ++ep;

libc/src/stdio.c

@@ -1,13 +1,14 @@
 /// @file stdio.c
 /// @brief Standard I/0 functions.
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include <sys/errno.h>
-#include "stdio.h"
+#include "sys/errno.h"
 #include "ctype.h"
-#include "string.h"
 #include "stdbool.h"
+#include "stdio.h"
+#include "strerror.h"
+#include "string.h"
 #include "sys/unistd.h"
 
 void putchar(int character)
@@ -15,7 +16,7 @@ void putchar(int character)
     write(STDOUT_FILENO, &character, 1);
 }
 
-void puts(char *str)
+void puts(const char *str)
 {
     write(STDOUT_FILENO, str, strlen(str));
 }
@@ -23,17 +24,18 @@ void puts(char *str)
 int getchar(void)
 {
     char c;
-    while (read(STDIN_FILENO, &c, 1) == 0)
+    while (read(STDIN_FILENO, &c, 1) == 0) {
         continue;
-
+    }
     return c;
 }
 
 char *gets(char *str)
 {
     // Check the input string.
-    if (str == NULL)
+    if (str == NULL) {
         return NULL;
+    }
     // Buffer for reading input.
     char buffer[GETS_BUFFERSIZE];
     memset(buffer, '\0', GETS_BUFFERSIZE);
@@ -60,7 +62,7 @@ char *gets(char *str)
             }
         } else {
             // The character is stored at address, and the pointer is incremented.
-            *cptr++ = ch;
+            *cptr++ = (char)ch;
         }
     }
     // Add the null-terminating character.
@@ -74,13 +76,15 @@ char *gets(char *str)
 int atoi(const char *str)
 {
     // Check the input string.
-    if (str == NULL)
+    if (str == NULL) {
         return 0;
+    }
     // Initialize sign, the result variable, and two indices.
     int sign = (str[0] == '-') ? -1 : +1, result = 0, i;
     // Find where the number ends.
-    for (i = (sign == -1) ? 1 : 0; (str[i] != '\0') && isdigit(str[i]); ++i)
+    for (i = (sign == -1) ? 1 : 0; (str[i] != '\0') && isdigit(str[i]); ++i) {
         result = (result * 10) + str[i] - '0';
+    }
     return sign * result;
 }
 
@@ -90,48 +94,46 @@ long strtol(const char *str, char **endptr, int base)
     long acc, cutoff;
     int c;
     int neg, any, cutlim;
-    /*
-     * Skip white space and pick up leading +/- sign if any.
-     * If base is 0, allow 0x for hex and 0 for octal, else
-     * assume decimal; if base is already 16, allow 0x.
-     */
+    // Skip white space and pick up leading +/- sign if any.
+    // If base is 0, allow 0x for hex and 0 for octal, else
+    // assume decimal; if base is already 16, allow 0x.
     s = str;
     do {
         c = (unsigned char)*s++;
     } while (isspace(c));
     if (c == '-') {
         neg = 1;
-        c   = *s++;
+        c   = (int)*s++;
     } else {
         neg = 0;
-        if (c == '+')
-            c = *s++;
+        if (c == '+') {
+            c = (int)*s++;
+        }
     }
     if ((base == 0 || base == 16) &&
         c == '0' && (*s == 'x' || *s == 'X')) {
-        c = s[1];
+        c = (int)s[1];
         s += 2;
         base = 16;
     }
-    if (base == 0)
+    if (base == 0) {
         base = c == '0' ? 8 : 10;
-    /*
-     * Compute the cutoff value between legal numbers and illegal
-     * numbers.  That is the largest legal value, divided by the
-     * base.  An input number that is greater than this value, if
-     * followed by a legal input character, is too big.  One that
-     * is equal to this value may be valid or not; the limit
-     * between valid and invalid numbers is then based on the last
-     * digit.  For instance, if the range for longs is
-     * [-2147483648..2147483647] and the input base is 10,
-     * cutoff will be set to 214748364 and cutlim to either
-     * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
-     * a value > 214748364, or equal but the next digit is > 7 (or 8),
-     * the number is too big, and we will return a range error.
-     *
-     * Set any if any `digits' consumed; make it negative to indicate
-     * overflow.
-     */
+    }
+    // Compute the cutoff value between legal numbers and illegal
+    // numbers.  That is the largest legal value, divided by the
+    // base.  An input number that is greater than this value, if
+    // followed by a legal input character, is too big.  One that
+    // is equal to this value may be valid or not; the limit
+    // between valid and invalid numbers is then based on the last
+    // digit.  For instance, if the range for longs is
+    // [-2147483648..2147483647] and the input base is 10,
+    // cutoff will be set to 214748364 and cutlim to either
+    // 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
+    // a value > 214748364, or equal but the next digit is > 7 (or 8),
+    // the number is too big, and we will return a range error.
+    //
+    // Set any if any `digits' consumed; make it negative to indicate
+    // overflow.
     cutoff = neg ? LONG_MIN : LONG_MAX;
     cutlim = cutoff % base;
     cutoff /= base;
@@ -143,16 +145,19 @@ long strtol(const char *str, char **endptr, int base)
         cutlim = -cutlim;
     }
     for (acc = 0, any = 0;; c = (unsigned char)*s++) {
-        if (isdigit(c))
+        if (isdigit(c)) {
             c -= '0';
-        else if (isalpha(c))
+        } else if (isalpha(c)) {
             c -= isupper(c) ? 'A' - 10 : 'a' - 10;
-        else
+        } else {
             break;
-        if (c >= base)
+        }
+        if (c >= base) {
             break;
-        if (any < 0)
+        }
+        if (any < 0) {
             continue;
+        }
         if (neg) {
             if (acc < cutoff || (acc == cutoff && c > cutlim)) {
                 any   = -1;
@@ -175,16 +180,18 @@ long strtol(const char *str, char **endptr, int base)
             }
         }
     }
-    if (endptr != 0)
+    if (endptr != 0) {
         *endptr = (char *)(any ? s - 1 : str);
+    }
     return (acc);
 }
 
 int fgetc(int fd)
 {
     unsigned char c;
-    if (read(fd, &c, 1) <= 0)
+    if (read(fd, &c, 1) <= 0) {
         return EOF;
+    }
     return c;
 }
 
@@ -195,14 +202,31 @@ char *fgets(char *buf, int n, int fd)
 
     /* get max bytes or upto a newline */
     for (p = buf, n--; n > 0; n--) {
-        if ((c = fgetc(fd)) == EOF)
+        // Get the character.
+        c = fgetc(fd);
+        if (c == EOF) {
             break;
-        *p++ = c;
-        if (c == '\n')
+        }
+        *p++ = (char)c;
+        if (c == '\n') {
             break;
+        }
     }
     *p = 0;
-    if (p == buf || c == EOF)
+    if (p == buf || c == EOF) {
         return NULL;
+    }
     return (p);
-}
+}
+
+void perror(const char *s)
+{
+    if (s) {
+        puts(s);
+        putchar(':');
+        putchar(' ');
+    }
+    puts(strerror(errno));
+    putchar('\n');
+    putchar('\n');
+}

libc/src/stdlib.c

@@ -1,36 +1,37 @@
 /// @file stdlib.c
 /// @brief
-/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include "system/syscall_types.h"
+#include "stddef.h"
+#include "assert.h"
 #include "stdlib.h"
 #include "string.h"
-#include "assert.h"
+#include "system/syscall_types.h"
 
 /// @brief Number which identifies a memory area allocated through a call to
 /// malloc(), calloc() or realloc().
 #define MALLOC_MAGIC_NUMBER 0x600DC0DE
 
-static inline int __malloc_is_valid_ptr(void *ptr)
-{
-    return (ptr && (((size_t *)ptr)[-1] == MALLOC_MAGIC_NUMBER));
-}
-
-size_t malloc_usable_size(void *ptr)
-{
-    if (__malloc_is_valid_ptr(ptr))
-        return ((size_t *)ptr)[-2];
-    return 0;
-}
+typedef struct {
+    unsigned magic;
+    size_t size;
+} malloc_header_t;
 
 void *malloc(unsigned int size)
 {
-    size_t *_res, _size = 2 * sizeof(size_t) + size;
-    __inline_syscall1(_res, brk, _size);
-    _res[0] = size;
-    _res[1] = MALLOC_MAGIC_NUMBER;
-    return &_res[2];
+    assert(size && "Zero size requested.");
+    size_t *ptr;
+    // Compute the real size we need to allocate.
+    size_t real_size = size + sizeof(malloc_header_t);
+    // Allocate the memory.
+    __inline_syscall1(ptr, brk, real_size);
+    // Initialize the malloc header.
+    malloc_header_t *malloc_header = (malloc_header_t *)ptr;
+    malloc_header->magic           = MALLOC_MAGIC_NUMBER;
+    malloc_header->size            = size;
+    // Return the allocated memory.
+    return (void *)((char *)ptr + sizeof(malloc_header_t));
 }
 
 void *calloc(size_t num, size_t size)
@@ -55,8 +56,12 @@ void *realloc(void *ptr, size_t size)
         free(ptr);
         return NULL;
     }
+    // Get the malloc header.
+    malloc_header_t *malloc_header = (malloc_header_t *)((char *)ptr - sizeof(malloc_header_t));
+    // Check the header.
+    assert(malloc_header->magic == MALLOC_MAGIC_NUMBER && "This is not a valid pointer.");
     // Get the old size.
-    size_t old_size = malloc_usable_size(ptr);
+    size_t old_size = malloc_header->size;
     // Create the new pointer.
     void *newp = malloc(size);
     memset(newp, 0, size);
@@ -67,24 +72,46 @@ void *realloc(void *ptr, size_t size)
 
 void free(void *ptr)
 {
+    // Get the malloc header.
+    malloc_header_t *malloc_header = (malloc_header_t *)((char *)ptr - sizeof(malloc_header_t));
+    // Check the header.
+    assert(malloc_header->magic == MALLOC_MAGIC_NUMBER && "This is not a valid pointer.");
+    // Get the real pointer.
+    ptr = (char *)ptr - sizeof(malloc_header_t);
+    // Call the free.
     int _res;
-    if (__malloc_is_valid_ptr(ptr)) {
-        size_t *_ptr = (size_t *)ptr - 2;
-        __inline_syscall1(_res, brk, _ptr);
-    } else {
-        __inline_syscall1(_res, brk, ptr);
-    }
+    __inline_syscall1(_res, brk, ptr);
 }
 
 /// Seed used to generate random numbers.
-static int rseed = 0;
+static unsigned rseed = 0;
 
-void srand(int x)
+void srand(unsigned x)
 {
     rseed = x;
 }
 
-int rand()
+unsigned rand(void)
 {
     return rseed = (rseed * 1103515245U + 12345U) & RAND_MAX;
 }
+
+float randf(void)
+{
+    return ((float)rand() / (float)(RAND_MAX));
+}
+
+int randint(int lb, int ub)
+{
+    return lb + ((int)rand() % (ub - lb + 1));
+}
+
+unsigned randuint(unsigned lb, unsigned ub)
+{
+    return lb + (rand() % (ub - lb + 1));
+}
+
+float randfloat(float lb, float ub)
+{
+    return lb + (randf() * (ub - lb));
+}