Merge branch 'hotfix/v0.5.2'

MentOS version 0.5.0

.github/workflows/main.yml

@@ -0,0 +1,52 @@
+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

.gitignore

@@ -1,3 +1,15 @@
+# Covers Visual Studio Code
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+!.vscode/*.code-snippets
+# Local History for Visual Studio Code
+.history/
+# Built Visual Studio Code Extensions
+*.vsix
+
 # Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and WebStorm
 # Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
 
@@ -101,4 +113,10 @@ src/initscp/initfscp
 .DS_Store
 
 # OS filesystem files.
-files/bin/**
+files/bin/**
+
+# ISO creation files.
+iso/boot/*.bin
+
+# Visual Studio Code
+.vscode

.travis.jml

@@ -1,23 +0,0 @@
-dist      : xenial
-sudo      : required
-language  : c
-
-matrix:
-  include:
-    - compiler: gcc
-      addons:
-        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - gcc-5
-      env: COMPILER=gcc-5
-
-before_install:
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq nasm
-
-script:
-  - mkdir build
-  - cd build
-  - cmake -DCMAKE_C_COMPILER=$COMPILER .. && make

CMakeLists.txt

@@ -1,158 +1,211 @@
 # =============================================================================
 # Set the minimum required version of cmake.
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.1...3.22)
 # Initialize the project.
-project(MentOs)
+project(mentos C ASM)
 
 # =============================================================================
+# BUILD TYPE (Debug/Release)
+# =============================================================================
+
 # Set the default build type to Debug.
 if(NOT CMAKE_BUILD_TYPE)
-  message(STATUS "Setting build type to 'Debug' as none was specified.")
+    message(STATUS "Setting build type to 'Debug' as none was specified.")
-  set(CMAKE_BUILD_TYPE
+    set(CMAKE_BUILD_TYPE "Debug" CACHE STRING "Choose the type of build." FORCE)
-      "Debug"
-      CACHE STRING "Choose the type of build." FORCE)
 endif()
 
 # =============================================================================
+# DOCUMENTATION
+# =============================================================================
+add_subdirectory(doc/doxygen)
+
+# =============================================================================
+# OS-SPECIFIC COMPILERS
+# =============================================================================
+
 # Add operating system specific option.
 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.
+    # Set the Apple MacOSx compilers.
-  if(CMAKE_VERSION VERSION_LESS "3.6.0")
+    if(CMAKE_VERSION VERSION_LESS "3.6.0")
-    include(CMakeForceCompiler)
+        include(CMakeForceCompiler)
-    cmake_force_c_compiler(i386-elf-gcc Clang)
+        cmake_force_c_compiler(i386-elf-gcc Clang)
-    cmake_force_cxx_compiler(i386-elf-g++ Clang)
+        cmake_force_cxx_compiler(i386-elf-g++ Clang)
-  else()
+    else()
-    set(CMAKE_C_COMPILER i386-elf-gcc)
+        set(CMAKE_C_COMPILER i386-elf-gcc)
-    set(CMAKE_CXX_COMPILER i386-elf-g++)
+        set(CMAKE_CXX_COMPILER i386-elf-g++)
-    set(CMAKE_AR i386-elf-ar)
+        set(CMAKE_AR i386-elf-ar)
-  endif()
+    endif()
-  # Speicfy the linker.
+    # Speicfy the linker.
-  set(CMAKE_LINKER i386-elf-ld)
+    set(CMAKE_LINKER i386-elf-ld)
-  # Specify the linker flags.
+    # Specify the linker flags.
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -nostdlib")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -nostdlib")
-
 elseif((${CMAKE_HOST_SYSTEM_NAME} STREQUAL "Windows") OR WIN32)
   # Windows set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -sdl)
-
 else()
-  # Generic Unix System
+    # Generic Unix System.
-  find_program(LSB_RELEASE_EXEC lsb_release)
+    # Find the `lsb_release` program.
-  execute_process(
+    find_program(LSB_RELEASE_EXEC lsb_release HINTS /usr/bin/ /usr/local/bin/)
-    COMMAND "${LSB_RELEASE_EXEC}" --short --release
+    # Mark the program path as advanced, we do not want it to appear as an option.
-    OUTPUT_VARIABLE LSB_RELEASE_VERSION_SHORT
+    mark_as_advanced(LSB_RELEASE_EXEC)
-    OUTPUT_STRIP_TRAILING_WHITESPACE)
+    # Get the version.
-  message(STATUS "LSB version    : ${LSB_RELEASE_VERSION_SHORT}")
+    execute_process(
-  if(${LSB_RELEASE_VERSION_SHORT} MATCHES "^18")
+        COMMAND "${LSB_RELEASE_EXEC}" --short --release
-    # Ubuntu 18 set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -sdl)
+        OUTPUT_VARIABLE LSB_RELEASE_VERSION_SHORT
-  elseif(${LSB_RELEASE_VERSION_SHORT} MATCHES "^19")
+        OUTPUT_STRIP_TRAILING_WHITESPACE
-    # Ubuntu 19
+    )
-    set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -display gtk)
+    message(STATUS "LSB version    : ${LSB_RELEASE_VERSION_SHORT}")
-  elseif(${LSB_RELEASE_VERSION_SHORT} MATCHES "^20")
+    if(${LSB_RELEASE_VERSION_SHORT} MATCHES "^18")
-    # Ubuntu 20
+        # Ubuntu 18 set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -sdl)
-    set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -display gtk)
+    elseif(${LSB_RELEASE_VERSION_SHORT} MATCHES "^19")
-  else()
+        # Ubuntu 19
-    # set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -sdl)
+        set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -display gtk)
-  endif()
+    elseif(${LSB_RELEASE_VERSION_SHORT} MATCHES "^20")
+        # Ubuntu 20
+        set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -display gtk)
+    else()
+        # set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -sdl)
+    endif()
 endif()
 
 # =============================================================================
-# Add the debugging option.
+# COMPILATION
-set(DEBUGGING_TYPE
-    "DEBUG_STDIO"
-    CACHE STRING "Chose the type of debugging: DEBUG_STDIO DEBUG_LOG")
-set_property(CACHE DEBUGGING_TYPE PROPERTY STRINGS DEBUG_STDIO DEBUG_LOG)
-if("${DEBUGGING_TYPE}" STREQUAL "DEBUG_STDIO" OR "${DEBUGGING_TYPE}" STREQUAL "DEBUG_LOG")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D${DEBUGGING_TYPE}")
-  message(STATUS "Setting debugging type to ${DEBUGGING_TYPE}.")
-else()
-  message(FATAL_ERROR "Debugging type ${DEBUGGING_TYPE} is not valid.")
-endif()
-
 # =============================================================================
+
 # Add the sub-directories.
 add_subdirectory(programs)
 add_subdirectory(programs/tests)
 add_subdirectory(mentos)
-add_subdirectory(initscp)
 add_subdirectory(libc)
-add_subdirectory(doc)
 
 # =============================================================================
-# Target to generate the initrd filesystem.
+# FILESYSTEM
-add_custom_target(
+# =============================================================================
-  initrd
+
-  COMMAND echo "---------------------------------------------"
+# MentOS is compatible with EXT2 fileystems. This target generates an EXT2
-  COMMAND echo "Initializing 'initrd'..."
+# fileystem using the content of the `files` folder.
-  COMMAND echo "---------------------------------------------"
+add_custom_target(filesystem
-  COMMAND initfscp -s ${CMAKE_SOURCE_DIR}/files -t ${CMAKE_BINARY_DIR}/initrd -m /dev
+    BYPRODUCTS ${CMAKE_BINARY_DIR}/rootfs.img
-  COMMAND echo "---------------------------------------------"
+    COMMAND echo '============================================================================='
-  COMMAND echo "Done!"
+    COMMAND echo 'Creating EXT2 filesystem...'
-  COMMAND echo "---------------------------------------------"
+    COMMAND echo '============================================================================='
-  DEPENDS initfscp
+    COMMAND mkdir -p ${CMAKE_SOURCE_DIR}/files/proc
-  DEPENDS all_programs all_tests)
+    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 echo '============================================================================='
+    COMMAND echo 'Done!'
+    COMMAND echo '============================================================================='
+    DEPENDS all_programs all_tests
+)
 
 # =============================================================================
-# Update GDB symbol file.
+# EMULATION SERIAL OUTPUT OPTION
-add_custom_target(
+# =============================================================================
-  gdb_file
+# Set the list of valid emulator output options.
-  COMMAND echo "symbol-file ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin" >> ${CMAKE_BINARY_DIR}/.gdbinit
+set(EMULATOR_OUTPUT_TYPES OUTPUT_STDIO OUTPUT_LOG)
-  COMMAND echo "exec-file   ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin" >> ${CMAKE_BINARY_DIR}/.gdbinit
+# Add the emulator output option.
-  COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/mentos/kernel.bin > ${CMAKE_BINARY_DIR}/.gdbinit
+set(EMULATOR_OUTPUT_TYPE "OUTPUT_STDIO" CACHE STRING "Chose the type of emulator output: ${EMULATOR_OUTPUT_TYPES}")
-  COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin >> ${CMAKE_BINARY_DIR}/.gdbinit
+# List of emulator output options.
-  COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/programs/tests/test_* >> ${CMAKE_BINARY_DIR}/.gdbinit
+set_property(CACHE EMULATOR_OUTPUT_TYPE PROPERTY STRINGS ${EMULATOR_OUTPUT_TYPES})
-  COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/programs/prog_* >> ${CMAKE_BINARY_DIR}/.gdbinit
+# Check which emulator output option is currently active.
-  COMMAND echo "break boot.c: boot_main" >> ${CMAKE_BINARY_DIR}/.gdbinit
+list(FIND EMULATOR_OUTPUT_TYPES ${EMULATOR_OUTPUT_TYPE} INDEX)
-  COMMAND echo "break kernel.c: kmain" >> ${CMAKE_BINARY_DIR}/.gdbinit
+if(index EQUAL -1)
-  COMMAND echo "target remote localhost:1234" >> ${CMAKE_BINARY_DIR}/.gdbinit
+    message(FATAL_ERROR "Emulator output type ${EMULATOR_OUTPUT_TYPE} is not valid.")
-  DEPENDS ${PROJECT_NAME}_bootloader
+else()
-  DEPENDS all_programs all_tests
+    message(STATUS "Setting emulator output type to ${EMULATOR_OUTPUT_TYPE}.")
-  DEPENDS libc)
+endif()
 
 # =============================================================================
-# Update GDB symbol file.
+# EMULATOR CONFIGURATION
-add_custom_target(
-  gdb_file_clion_embedded
-  COMMAND echo "symbol-file ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin" >> ${CMAKE_BINARY_DIR}/.gdbinit
-  COMMAND echo "exec-file   ${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.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/prog_* >> ${CMAKE_BINARY_DIR}/.gdbinit
-  DEPENDS ${PROJECT_NAME}_bootloader
-  DEPENDS all_programs all_tests
-  DEPENDS libc)
-
 # =============================================================================
-# Set memory size.
-set(MEMORY_SIZE 1096M)
 
-# =============================================================================
+# Set the emulator.
-# Builds the code and runs qemu with the built Os.
 set(EMULATOR qemu-system-i386)
-if(${DEBUGGING_TYPE} STREQUAL DEBUG_LOG)
+# Set the debug type.
-  set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -serial file:serial.log)
+if(${EMULATOR_OUTPUT_TYPE} STREQUAL OUTPUT_LOG)
-elseif(${DEBUGGING_TYPE} STREQUAL DEBUG_STDIO)
+    set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -serial file:${CMAKE_BINARY_DIR}/serial.log)
-  set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -serial stdio)
+elseif(${EMULATOR_OUTPUT_TYPE} STREQUAL OUTPUT_STDIO)
-endif(${DEBUGGING_TYPE} STREQUAL DEBUG_LOG)
+    set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -serial stdio)
+endif(${EMULATOR_OUTPUT_TYPE} STREQUAL OUTPUT_LOG)
+# Set the type of video.
 set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -vga std)
-set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -m ${MEMORY_SIZE})
+# Set the amount of memory.
-set(EMULATOR_KERNEL -kernel mentos/kernel-bootloader.bin)
+set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -m 1096M)
-set(EMULATOR_FS -initrd initrd)
+# Set the EXT2 drive.
-
+set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -drive file=${CMAKE_BINARY_DIR}/rootfs.img,format=raw)
-add_custom_target(
-  qemu
-  COMMAND ${EMULATOR} ${EMULATOR_FLAGS} ${EMULATOR_KERNEL} ${EMULATOR_FS}
-  DEPENDS kernel-bootloader.bin initrd all_programs all_tests libc)
 
 # =============================================================================
-# Builds the code and runs qemu with the built Os.
+# Booting with QEMU for fun
-set(EMULATOR_FLAGS_GDB ${EMULATOR_FLAGS} -s -S)
+# =============================================================================
 
+# This first target runs the emualtor passing the kernel binary file.
 add_custom_target(
-  qemu-gdb
+    qemu
-  COMMAND ${EMULATOR} ${EMULATOR_FLAGS_GDB} ${EMULATOR_KERNEL} ${EMULATOR_FS} &
+    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"
-  DEPENDS gdb_file kernel-bootloader.bin initrd)
+    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -kernel ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin
+    DEPENDS kernel-bootloader.bin
+)
 
-add_custom_target(all-execs-clion-embedded DEPENDS gdb_file_clion_embedded kernel-bootloader.bin initrd)
+# =============================================================================
+# Booting with QEMU+GDB for debugging
+# =============================================================================
+
+# First, we need to generate a GDB file containing all the symbols of all our
+# executables.
+add_custom_target(
+    .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}/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
+    DEPENDS all_programs
+    DEPENDS all_tests
+    DEPENDS libc
+)
+
+# This second target runs the emualtor passing the kernel binary file, and also
+# the `-s -S` options. This basically tells the emulator to run the kernel in
+# debug mode, and pause it up until a debugger connects to it.
+add_custom_target(
+    qemu-gdb
+    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 echo "\n\n"
+    COMMAND echo "Now, QEMU has loaded the kernel, and it is waiting that you\n"
+    COMMAND echo "remotely connect to it. To start debugging, open a new shell\n"
+    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
+    DEPENDS .gdbinit
+)
+
+# =============================================================================
+# Booting with QEMU+GRUB
+# =============================================================================
+
+# First, we need to build the ISO for the cdrom.
+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 grub-mkrescue -o ${CMAKE_BINARY_DIR}/cdrom.iso ${CMAKE_BINARY_DIR}/iso
+  DEPENDS kernel-bootloader.bin
+)
+
+# This third target runs the emualtor, but this time, the kernel binary file is
+# inside the cdrom, so we will not pass the `-kernel` option. We will pass the
+# `-cdrom` option and the `-boot d` option, all the other options will remain
+# the same.
+add_custom_target(
+    qemu-grub
+    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -boot d -cdrom ${CMAKE_BINARY_DIR}/cdrom.iso
+    DEPENDS cdrom.iso
+)

CODING_STYLE.md

@@ -1,6 +0,0 @@
-# Coding Style
-If you'd like to contribute you are welcome, thus refer to the following coding
-styles please:
-
-* **C**: _the Linux kernel coding style_
-  https://www.kernel.org/doc/html/v4.10/process/coding-style.html

LICENSE.md

@@ -1,7 +1,6 @@
 MIT License
 
-Copyright (c) 2019 Alessandro Danese, Enrico Fraccaroli, Luigi Capogrosso, 
+Copyright (c) 2014-2022 MentOs-Team.
-Mirco De Marchi
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -26,12 +26,49 @@ 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. Prerequisites
+## 2. Implemented features
+Follows the list of implemented features:
+
+**Processes and Events**
+ - [x] Memory protection (User vs Kernel);
+ - [x] Processes;
+ - [x] Scheduler (synchronous and asynchronous);
+ - [x] Interrupts and Exceptions;
+ - [x] Signals;
+ - [x] Timers and RTC;
+ - [x] Wait-queues;
+ - [x] System Calls;
+ - [ ] Multi-core;
+ 
+**Memory**
+ - [x] Paging;
+ - [x] Buddy System;
+ - [x] Slab Allocation;
+ - [x] Zone Allocator;
+ - [x] Cache Allocator;
+ - [x] Heap;
+ - [x] Virtual Addressing;
+
+**Filesystem**
+ - [x] Virtual Filesystem (VFS);
+ - [x] Initramfs;
+ - [x] EXT2;
+ - [x] Procfs;
+
+**Input/Output**
+ - [x] Programmable Interrupt Controller (PIC) drivers;
+ - [x] Keyboard drivers (IT/ENG layouts);
+ - [x] Video drivers;
+ - [ ] VGA drivers;
+
+I will try to keep it updated...
+
+## 3. Prerequisites
 
 MentOS is compatible with the main **unix-based** operating systems. It has been
 tested with *Ubuntu*, *WSL1*, *WSL2*, and  *MacOS*.
 
-### 2.1. Generic Prerequisites
+### 3.1. Generic Prerequisites
 
 #### 3.1.1. Compile
 
@@ -43,6 +80,7 @@ For compiling the system:
  - cmake
  - git
  - ccmake (suggested)
+ - e2fsprogs (should be already installed)
 
 Under **MacOS**, for compiling, you have additional dependencies:
 
@@ -59,18 +97,18 @@ To execute the operating system, you need to install:
 
 For debugging we suggest using:
 
- - cgdb
+ - gdb or cgdb
- - xterm
 
-### 2.2. installation Prerequisites
+### 3.2. installation 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-i386 
+sudo apt-get install -y build-essential git cmake qemu-system-x86 nasm e2fsprogs
-sudo apt-get install -y cgdb xterm
+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.
@@ -79,13 +117,13 @@ then type the following commands:
 
 ```bash
 brew update && brew upgrade
-brew install i386-elf-binutils i386-elf-gcc git cmake qemu nasm
+brew install i386-elf-binutils i386-elf-gcc git cmake qemu nasm e2fsprogs
-brew install cgdb xterm #<- for debug only
+brew install gdb cgdb #<- for debug only
 ```
 
-## 3. Compiling MentOS
+## 4. Compiling MentOS and generating the EXT2 filesystem
 
-Compile and boot MentOS with qemu:
+Compile MentOS with:
 
 ```bash
 cd <clone_directory>
@@ -93,12 +131,76 @@ mkdir build
 cd build
 cmake ..
 make
+```
+
+Then, 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
+
+Boot MentOS with qemu:
+
+```bash
 make qemu
 ```
 
 To login, use one of the usernames listed in `files/etc/passwd`.
 
-## 4. Change the scheduling algorithm
+## 6. 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++
+#define pr_emerg(...)
+#define pr_alert(...)
+#define pr_crit(...)
+#define pr_err(...)
+#define pr_warning(...)
+#define pr_notice(...)
+#define pr_info(...)
+#define pr_debug(...)
+#define pr_default(...)
+```
+
+You use them like you would use a `printf`:
+```C++
+    if (fd < 0) {
+        pr_err("Failed to open file '%s', received file descriptor %d.\n", filename, fd);
+        return 1;
+    }
+```
+
+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++
+#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.
+```
+
+You can change the logging level by including the following lines at the beginning of your source code:
+```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
+```
+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
 
 MentOS provides three different scheduling algorithms:
 
@@ -152,29 +254,63 @@ make
 make qemu
 ```
 
-## 5. Use Debugger
+## 8. Use Debugger
 
-If you want to use GDB to debug MentOS:
+If you want to use GDB to debug MentOS, first you need to compile everything:
 
 ```bash
 cd build
 cmake ..
 make
-make qemu-gdb
 ```
 
-If you did everything correctly, you should have 3 windows with:
+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.
+```bash
+make gdb_file
+```
 
-1. Kernel Booting on qemu
+Finally, you run qemu in debugging mode with:
-2. Shell with video printing of statistics previously discussed
+```bash
-3. Debugger cgdb with code screening
+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 .'
+```
 
-## Developers
+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.
 
-Main Developers:
+By default I placed a breakpoint at the begginning of 1) the bootloader, 2) the `kmain` function of the kernel.
+
+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*:
+```bash
+Breakpoint 1, boot_main (...) at .../mentos/src/boot.c:220
+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*:
+```bash
+Breakpoint 2, kmain (...) at .../mentos/src/kernel.c:95
+95      {
+```
+
+## 9. Contributors
+
+Project Manager:
 
 * [Enrico Fraccaroli](https://github.com/Galfurian)
-    - Mr. Wolf
+
+Developers:
 * [Alessandro Danese](https://github.com/alessandroDanese88), [Luigi Capogrosso](https://github.com/luigicapogrosso), [Mirco De Marchi](https://github.com/mircodemarchi)
     - Protection ring
     - libc

TODO.md

@@ -1 +0,0 @@
-# TODOs

doc/doxygen/CMakeLists.txt

@@ -2,12 +2,12 @@
 find_package(Doxygen)
 
 if (DOXYGEN_FOUND)
-    set(DOXYGEN_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/doc_doxygen)
+    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}/Doxygen)
+    set(DOXYFILE_IN  ${CMAKE_CURRENT_SOURCE_DIR}/Doxyfile)
-    set(DOXYFILE_OUT ${CMAKE_CURRENT_BINARY_DIR}/Doxygen)
+    set(DOXYFILE_OUT ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile)
     configure_file(${DOXYFILE_IN} ${DOXYFILE_OUT} @ONLY)
 
     # Copy the files needd by the documentation.
@@ -19,19 +19,19 @@ if (DOXYGEN_FOUND)
     file(MAKE_DIRECTORY ${DOXYGEN_OUTPUT_DIR})
 
     add_custom_command(
-            OUTPUT ${DOXYGEN_INDEX_FILE}
+        OUTPUT ${DOXYGEN_INDEX_FILE}
-            COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE_OUT}
+        COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE_OUT}
 
-            MAIN_DEPENDENCY ${DOXYFILE_OUT} ${DOXYFILE_IN}
+        MAIN_DEPENDENCY ${DOXYFILE_OUT} ${DOXYFILE_IN}
-            COMMENT "Generating docs"
+        COMMENT "Generating docs"
     )
     add_custom_target(
-            Doxygen
+        doxygen_doc
-            DEPENDS
+        DEPENDS
-            ${DOXYGEN_INDEX_FILE}
+        ${DOXYGEN_INDEX_FILE}
-            ${DOXYFILE_IN}
+        ${DOXYFILE_IN}
-            ${DOXYFILE_CSS}
+        ${DOXYFILE_CSS}
-            ${DOXYFILE_HEADER}
+        ${DOXYFILE_HEADER}
-            ${DOXYFILE_FOOTER}
+        ${DOXYFILE_FOOTER}
     )
 endif (DOXYGEN_FOUND)

doc/doxygen/Doxyfile

@@ -38,7 +38,7 @@ PROJECT_NAME           = MentOS
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 0.3.0
+PROJECT_NUMBER         = 0.5.2
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
@@ -853,7 +853,7 @@ INPUT_ENCODING         = UTF-8
 # C comment), *.py, *.pyw, *.f90, *.f95, *.f03, *.f08, *.f, *.for, *.tcl, *.vhd,
 # *.vhdl, *.ucf, *.qsf and *.ice.
 
-FILE_PATTERNS          = *.c *.h
+FILE_PATTERNS          = *.c *.h *.S
 
 # The RECURSIVE tag can be used to specify whether or not subdirectories should
 # be searched for input files as well.
@@ -2250,7 +2250,7 @@ HIDE_UNDOC_RELATIONS   = YES
 # set to NO
 # The default value is: YES.
 
-HAVE_DOT               = YES
+HAVE_DOT               = NO
 
 # The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
 # to run in parallel. When set to 0 doxygen will base this on the number of
@@ -2491,7 +2491,7 @@ DOT_GRAPH_MAX_NODES    = 50
 # Minimum value: 0, maximum value: 1000, default value: 0.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-MAX_DOT_GRAPH_DEPTH    = 0
+MAX_DOT_GRAPH_DEPTH    = 3
 
 # Set the DOT_TRANSPARENT tag to YES to generate images with a transparent
 # background. This is disabled by default, because dot on Windows does not seem

doc/doxygen/doxygen.scss

@@ -7,11 +7,22 @@ $cyan-color: #56b6c2;
 $yellow-color: #e5c07b;
 $blue-color: #61afef;
 $gutter-color: #4b5263;
-// $code-font: "Courier New", Courier, "Lucida Sans Typewriter", "Lucida Typewriter", monospace;
+
-$code-font: monaco,
+/* font families */
-Consolas,
+
-"Lucida Console",
+$page-font-family: Roboto, Lucida, sans-serif;
-monospace;
+$code-font-family: Consolas, monospace, fixed;
+
+/* font sizes */
+
+$title-font-size: 22px;
+$page-font-size: 16px;
+$code-font-size: 14px;
+$page-line-height: $page-font-size+6px;
+$code-line-height: $code-font-size+4px;
+
+/* colors */
+
 $title-fg-color: $white-color;
 $title-bg-color: $black-color;
 $menu-bg-color: $gutter-color;
@@ -69,7 +80,10 @@ table,
 div,
 p,
 dl {
-    font: 400 14px/22px Roboto, sans-serif;
+    font-size: $page-font-size;
+    font-family: $page-font-family;
+    font-weight: 400;
+    line-height: $page-line-height;
     display: block;
     margin-block-start: 0em;
     margin-block-end: 0em;
@@ -89,7 +103,10 @@ ul {
 
 p.reference,
 p.definition {
-    font: 400 14px/22px Roboto, sans-serif;
+    font-size: $page-font-size;
+    font-family: $page-font-family;
+    font-weight: 400;
+    line-height: $page-line-height;
 }
 
 
@@ -100,7 +117,10 @@ h1.groupheader {
 }
 
 .title {
-    font: 400 14px/28px Roboto, sans-serif;
+    font-size: $page-font-size;
+    font-family: $page-font-family;
+    font-weight: 400;
+    line-height: $page-line-height;
     font-size: 150%;
     font-weight: bold;
     margin: 10px 2px;
@@ -205,8 +225,7 @@ span.legend {
 }
 
 span.arrow {
-    /* width: 32px; */
+    width: 16px;
-    padding-left: 0px;
 }
 
 h3.version {
@@ -327,7 +346,7 @@ pre.fragment {
     overflow: auto;
     word-wrap: break-word;
     line-height: 125%;
-    font-family: $code-font;
+    font-family: $code-font-family;
     font-size: 105%;
     color: $code-fg-color;
 }
@@ -342,10 +361,9 @@ div.fragment {
 }
 
 div.line {
-    font-family: monospace, fixed;
+    font-family: $code-font-family;
-    font-size: 13px;
+    font-size: $code-font-size;
-    min-height: 13px;
+    line-height: $code-line-height;
-    line-height: 1.0;
     text-wrap: unrestricted;
     white-space: -moz-pre-wrap;
     /* Moz */
@@ -652,7 +670,7 @@ table.memberdecls {
 
 .memItemLeft,
 .memItemRight {
-    font-family: $code-font;
+    font-family: $code-font-family;
 }
 
 .mdescLeft,
@@ -780,7 +798,7 @@ table.memberdecls {
 }
 
 .memname {
-    font-family: $code-font;
+    font-family: $code-font-family;
     font-weight: 400;
     margin-left: 6px;
 }
@@ -963,8 +981,8 @@ div.directory {
 .directory td.entry {
     white-space: nowrap;
     padding-right: 6px;
-    padding-top: 3px;
+    padding-top: 2px;
-    padding-bottom: 3px;
+    padding-bottom: 2px;
 }
 
 .directory td.entry a {
@@ -1024,8 +1042,8 @@ div.directory {
     font-family: Arial, Helvetica;
     font-weight: bold;
     font-size: 12px;
-    height: 14px;
+    height: $page-font-size;
-    width: 16px;
+    width: $page-font-size;
     display: inline-block;
     background-color: #728DC1;
     color: white;
@@ -1075,7 +1093,10 @@ div.directory {
 }
 
 table.directory {
-    font: 400 14px Roboto, sans-serif;
+    font-size: $page-font-size;
+    font-family: $page-font-family;
+    font-weight: 400;
+    line-height: $page-line-height;
 }
 
 
@@ -1126,6 +1147,7 @@ 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,
@@ -1273,7 +1295,7 @@ table.classindex {
 }
 
 div.ingroups {
-    font-size: 8pt;
+    font-size: 10pt;
     width: 50%;
     text-align: left;
 }
@@ -1687,7 +1709,7 @@ tr.heading h2 {
 #powerTip div {
     margin: 0px;
     padding: 0px;
-    font: 12px/16px Roboto, sans-serif;
+    font: 12px/16px $page-font-family;
 }
 
 #powerTip:before,
@@ -1862,15 +1884,19 @@ tr.heading h2 {
     #top {
         display: none;
     }
+
     #side-nav {
         display: none;
     }
+
     #nav-path {
         display: none;
     }
+
     body {
         overflow: visible;
     }
+
     h1,
     h2,
     h3,
@@ -1879,12 +1905,15 @@ tr.heading h2 {
     h6 {
         page-break-after: avoid;
     }
+
     .summary {
         display: none;
     }
+
     .memitem {
         page-break-inside: avoid;
     }
+
     #doc-content {
         margin-left: 0 !important;
         height: auto !important;

doc/doxygen/footer.html

@@ -0,0 +1,40 @@
+        <!-- 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

@@ -0,0 +1,66 @@
+<!-- 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/footer.html

@@ -1,38 +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 $datetime.
-        </li>
-        <li class="footer-info-copyright">
-            MentOs © 2014–2021 the MentOs team, and numerous contributors.<br>
-            It is available for use and modification under the&#160;
-            <a href="$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/header.html

@@ -1,63 +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/scan_codes_it.md

@@ -0,0 +1,105 @@
+
+#define KEY_LEFT_WIN      0xE05b
+#define KEY_RIGHT_WIN     0xE05c
+
+                        Normal  Shifted Ctrl    Alt
+KEY_A               0x001E  A           0x1E61  0x1E41  0x1E01  0x1E00  
+KEY_B               0x0030  B           0x3062  0x3042  0x3002  0x3000  
+KEY_C               0x002E  C           0x2E63  0x2E42  0x2E03  0x2E00  
+KEY_D               0x0020  D           0x2064  0x2044  0x2004  0x2000  
+KEY_E               0x0012  E           0x1265  0x1245  0x1205  0x1200  
+KEY_F               0x0021  F           0x2166  0x2146  0x2106  0x2100  
+KEY_G               0x0022  G           0x2267  0x2247  0x2207  0x2200  
+KEY_H               0x0023  H           0x2368  0x2348  0x2308  0x2300  
+KEY_I               0x0017  I           0x1769  0x1749  0x1709  0x1700  
+KEY_J               0x0024  J           0x246A  0x244A  0x240A  0x2400  
+KEY_K               0x0025  K           0x256B  0x254B  0x250B  0x2500  
+KEY_L               0x0026  L           0x266C  0x264C  0x260C  0x2600  
+KEY_M               0x0032  M           0x326D  0x324D  0x320D  0x3200  
+KEY_N               0x0031  N           0x316E  0x314E  0x310E  0x3100  
+KEY_O               0x0018  O           0x186F  0x184F  0x180F  0x1800  
+KEY_P               0x0019  P           0x1970  0x1950  0x1910  0x1900  
+KEY_Q               0x0010  Q           0x1071  0x1051  0x1011  0x1000  
+KEY_R               0x0013  R           0x1372  0x1352  0x1312  0x1300  
+KEY_S               0x001F  S           0x1F73  0x1F53  0x1F13  0x1F00  
+KEY_T               0x0014  T           0x1474  0x1454  0x1414  0x1400  
+KEY_U               0x0016  U           0x1675  0x1655  0x1615  0x1600  
+KEY_V               0x002F  V           0x2F76  0x2F56  0x2F16  0x2F00  
+KEY_W               0x0011  W           0x1177  0x1157  0x1117  0x1100  
+KEY_X               0x002D  X           0x2D78  0x2D58  0x2D18  0x2D00  
+KEY_Y               0x0015  Y           0x1579  0x1559  0x1519  0x1500  
+KEY_Z               0x002C  Z           0x2C7A  0x2C5A  0x2C1A  0x2C00
+
+KEY_1               0x0002  1 !         0x0231  0x0221  0x0000  0x7800
+KEY_2               0x0003  2 "         0x0332  0x0322  0x0300  0x7900
+KEY_3               0x0004  3 £         0x0433  0x049C  0x0000  0x7A00
+KEY_4               0x0005  4 $         0x0534  0x0524  0x0000  0x7B00
+KEY_5               0x0006  5 %         0x0635  0x0625  0x0000  0x7C00
+KEY_6               0x0007  6 &         0x0736  0x075E  0x071E  0x7D00
+KEY_7               0x0008  7 /         0x0837  0x0826  0x0000  0x7E00
+KEY_8               0x0009  8 (         0x0938  0x0928  0x0000  0x7F00
+KEY_9               0x000A  9 )         0x0A39  0x0A29  0x0000  0x8000
+KEY_0               0x000B  0 =         0x0B30  0x0B3D  0x0000  0x8100
+
+KEY_GRAVE           0x0029  \ |         0x295C  0x297C  0x0000  0x2900
+KEY_APOSTROPHE      0x000C  ' ?         0x0C27  0x0C3F  0x0000  0x8200
+KEY_I_ACC           0x000D  ì ^         0x0D8D  0x0D5E  0x0000  0x8300
+KEY_LEFT_BRAKET     0x001A  è é [       0x1A8A  0x1A82  0x0000  0x1A5B
+KEY_RIGHT_BRAKET    0x001B  + * ]       0x1B2B  0x1B2A  0x0000  0x1B5D
+KEY_SEMICOLON       0x0027  ò ç @       0x2795  0x2780  0x0000  0x2740
+KEY_DOUBLE_QUOTES   0x0028  à ° #       0x2885  0x28A7  0x0000  0x2823
+KEY_BACKSLASH       0x002B  ù §         0x2B97  0x2BA7  0x0000  0x2B00
+KEY_KP_LESS         0x0056  < >         0x563C  0x563E  0x0000  0x5600
+KEY_COMMA           0x0033  , ;         0x332C  0x333B  0x0000  0x3300
+KEY_PERIOD          0x0034  . :         0x342E  0x343A  0x0000  0x3400
+KEY_MINUS           0x0035  - _         0x352D  0x355F  0x0000  0x3500
+
+KEY_F1              0x003B  F1          0x3B00  0x5400  0x5E00  0x6800
+KEY_F2              0x003C  F2          0x3C00  0x5500  0x5F00  0x6900
+KEY_F3              0x003D  F3          0x3D00  0x5600  0x6000  0x6A00
+KEY_F4              0x003E  F4          0x3E00  0x5700  0x6100  0x6B00
+KEY_F5              0x003F  F5          0x3F00  0x5800  0x6200  0x6C00
+KEY_F6              0x0040  F6          0x4000  0x5900  0x6300  0x6D00
+KEY_F7              0x0041  F7          0x4100  0x5A00  0x6400  0x6E00
+KEY_F8              0x0042  F8          0x4200  0x5B00  0x6500  0x6F00
+KEY_F9              0x0043  F9          0x4300  0x5C00  0x6600  0x7000
+KEY_F10             0x0044  F10         0x4400  0x5D00  0x6700  0x7100
+KEY_F11             0x0057  F11         0x5700  0x5900  0x5B00  0x5D00
+KEY_F12             0x0058  F12         0x5800  0x5A00  0x5C00  0x5E00
+
+KEY_BACKSPACE       0x000E  BackSpace   0x0E08  0x0E08  0x0E7F  0x0E00
+KEY_ENTER           0x001C  Enter       0x1C0D  0x1C0D  0x1C0A  0xA600
+KEY_ESCAPE          0x0001  Esc         0x011B  0x011B  0x011B  0x0100
+KEY_TAB             0x000F  Tab         0x0F09  0x0F00  0x9400  0xA500
+KEY_SPACE           0x0039  SpaceBar    0x3920  0x3920  0x3920  0x3920
+
+KEY_INSERT          0xE052  Ins         0x5200  0x5230  0x9200  0xA200
+KEY_HOME            0xE047  Home        0x4700  0x4737  0x7700  0x9700
+KEY_PAGE_UP         0xE049  PgUp        0x4900  0x4939  0x8400  0x9900
+KEY_DELETE          0xE053  Del         0x5300  0x532E  0x9300  0xA300
+KEY_END             0xE04F  End         0x4F00  0x4F31  0x7500  0x9F00
+KEY_PAGE_DOWN       0xE051  PgDn        0x5100  0x5133  0x7600  0xA100
+
+KEY_UP_ARROW        0xE048  Up Arrow    0x4800  0x4838  0x8D00  0x9800
+KEY_DOWN_ARROW      0xE050  Down Arrow  0x5000  0x5032  0x9100  0xA000
+KEY_LEFT_ARROW      0xE04B  Left Arrow  0x4B00  0x4B34  0x7300  0x9B00
+KEY_RIGHT_ARROW     0xE04D  Right Arrow 0x4D00  0x4D36  0x7400  0x9D00
+
+KEY_KP_DIV          0xE035  Kp.Div      0xE035  0xE035  0x3500  0x3500
+KEY_KP_MUL          0x0037  Kp.Mul      0x372A  0x372A  0x3700  0x3700
+KEY_KP_SUB          0x004A  Kp.Sub      0x4A2D  0x4A2D  0x4A00  0x4A00
+KEY_KP_ADD          0x004E  Kp.Add      0x4E2B  0x4E2B  0x4E00  0x4E00
+KEY_KP_RETURN       0xE01C  Kp.Enter    0xE01C  0xE01C  0x1C00  0x1C00
+
+KEY_KP7             0x0047              0x4737  0x4737  0x4700  0x4700
+KEY_KP8             0x0048              0x4838  0x4838  0x4800  0x4800
+KEY_KP9             0x0049              0x4939  0x4939  0x4900  0x4900
+KEY_KP4             0x004B              0x4B34  0x4B34  0x4B00  0x4B00
+KEY_KP5             0x004C              0x4C35  0x4C35  0x4C00  0x4C00
+KEY_KP6             0x004D              0x4D36  0x4D36  0x4D00  0x4D00
+KEY_KP1             0x004F              0x4F31  0x4F31  0x4F00  0x4F00
+KEY_KP2             0x0050              0x5032  0x5032  0x5000  0x5000
+KEY_KP3             0x0051              0x5133  0x5133  0x5100  0x5100
+KEY_KP0             0x0052              0x5230  0x5230  0x5200  0x5200
+
+KEY_KP_DEC          0x0053              0x532E  0x532E  0x5300  0x5300

files/etc/motd

@@ -0,0 +1 @@
+Call `man` to have a list of all the commands.

files/etc/passwd

@@ -1,2 +1,2 @@
-root:root:0:0:Root User:/:/bin/shell
+root:root:0:0:Root User:/root:/bin/shell
-user:user:1000:1000:Normal User:/home/user:/bin/shell
+user:user:1000:1000:Normal User:/home/user:/bin/shell

files/usr/share/man/ls.man

@@ -0,0 +1,14 @@
+NAME
+    ls - list directory contents
+
+SYNOPSIS
+    ls [OPTIONS] [FILE/FOLDER]
+
+DESCRIPTION
+    List information about the given file, or the files contained in the given
+    folder. If not argument is provided it will list information about files
+    inside the current folder.
+    
+OPTIONS
+    -a  : list all entries.
+    -l  : show the entries as a detailed list.

initscp/CMakeLists.txt

@@ -1,30 +0,0 @@
-# ------------------------------------------------------------------------------
-# Initialize the project.
-project(initfscp C)
-
-# ------------------------------------------------------------------------------
-# Set the project name.
-set(PROJECT_NAME initfscp)
-
-if (CMAKE_CROSSCOMPILING)
-    set(CMAKE_C_COMPILER gcc)
-    set(CMAKE_CXX_COMPILER g++)
-    set(CMAKE_EXE_LINKER_FLAGS "")
-endif (CMAKE_CROSSCOMPILING)
-
-# ------------------------------------------------------------------------------
-# Set the compiler options (original).
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
-
-# ------------------------------------------------------------------------------
-# Add the source files.
-set(SOURCE_FILES src/initfscp.c)
-
-# ------------------------------------------------------------------------------
-# Add the executable.
-add_executable(initfscp ${SOURCE_FILES})
-
-

initscp/README.md

@@ -1,20 +0,0 @@
-----
-README
-initfscp - Autore di questa guida: Aleksej
-----
-
-initfscp e' un programma che serve a creare un'immagine contenente il file system utilizzato da MentOS.
-Consente di inserirci dei files e/o dei mountpoint (massimo 32) all'interno. 
-Per far ciò digitare il comando "initfscp [-m mountpoint1 -m mountpoint2 ... -m mountpoint n] file1 file2 ... nomefs" 
-
-dove:
-- -m mountpoint1 -m mountpoint2 ... -m mountpoint n (facoltativo) indicano i mountpoint da inserire nel filesystem appena creato. 
-- "file1 file2 ..." sono i files che inseriremo nel filesystem,
-- "nomefs" è il nome che daremo all'immagine.
-Ad esempio vogliamo inserire i file topolino, pippo e paperino nell'immagine che chiameremo disney, quindi digitiamo:
-  initfscp topolino pippo paperino disney
-così facendo initfscp genererà l'immagine disney.
-
-Altri comandi disponibili:
---help (-h) per visualizzare una guida più sintetica.
---version (-v) per visualizzare la versione utilizzata attualmente di initfscp.

initscp/src/initfscp.c

@@ -1,404 +0,0 @@
-/// @file   initfscp.c
-/// @brief
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdint.h>
-#include <libgen.h>
-#include <dirent.h>
-#include <assert.h>
-#include <time.h>
-#include <sys/stat.h>
-#include <dirent.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <errno.h>
-
-#define INITFSCP_VER "0.3.0"
-
-#define INITRD_NAME_MAX    255
-#define INITRD_MAX_FILES   128
-#define INITRD_MAX_FS_SIZE 1048576
-
-#define RESET   "\033[00m"
-#define BLACK   "\033[30m"
-#define RED     "\033[31m"
-#define GREEN   "\033[32m"
-#define YELLOW  "\033[33m"
-#define BLUE    "\033[34m"
-#define MAGENTA "\033[35m"
-#define CYAN    "\033[36m"
-#define WHITE   "\033[37m"
-
-static const char dt_char_array[] = {
-    '?', // DT_UNKNOWN = 0,
-    'p', //DT_FIFO = 1,
-    'c', //DT_CHR  = 2,
-    '*',
-    'd', //DT_DIR  = 4,
-    '*',
-    'b', //DT_BLK  = 6,
-    '*',
-    '-', //DT_REG  = 8,
-    '*',
-    'l', //DT_LNK  = 10,
-    '*',
-    's', //DT_SOCK = 12,
-    '*',
-    '?', //DT_WHT  = 14
-};
-
-/// @brief Information concerning a file.
-typedef struct initrd_file_t {
-    /// Number used as delimiter, it must be set to 0xBF.
-    int magic;
-    /// The inode of the file.
-    unsigned int inode;
-    /// The name of the file.
-    char name[INITRD_NAME_MAX];
-    /// The type of the file.
-    short int file_type;
-    /// The permissions mask.
-    unsigned int mask;
-    /// The id of the owner.
-    unsigned int uid;
-    /// The id of the group.
-    unsigned int gid;
-    /// Time of last access.
-    unsigned int atime;
-    /// Time of last data modification.
-    unsigned int mtime;
-    /// Time of last status change.
-    unsigned int ctime;
-    /// Offset of the starting address.
-    unsigned int offset;
-    /// Dimension of the file.
-    unsigned int length;
-} __attribute__((aligned(16))) initrd_file_t;
-
-/// @brief The details regarding the filesystem.
-/// @brief Contains the number of files inside the initrd filesystem.
-typedef struct initrd_t {
-    /// Number of files.
-    unsigned int nfiles;
-    /// List of headers.
-    initrd_file_t headers[INITRD_MAX_FILES];
-} __attribute__((aligned(16))) initrd_t;
-
-// Prepare a variable to keep track of the offsets inside the FS. By
-//  default skip the initial space for the FS details structure.
-static int fs_offset = sizeof(initrd_t);
-
-static inline void usage(char *prgname)
-{
-    printf("Usage:\n");
-    printf(" %s --help        For this screen\n", prgname);
-    printf(" %s --source [-s] The source directory.\n", prgname);
-    printf(" %s --target [-t] The target file for the initrd.\n", prgname);
-}
-
-static inline void version(char *prgname)
-{
-    printf("%s version: %s\n", prgname, INITFSCP_VER);
-}
-
-static inline int is_option_mount_point(char *arg)
-{
-    return ((strcmp(arg, "-m") == 0) || (strcmp(arg, "--mountpoint") == 0));
-}
-
-static inline int is_option_source(char *arg)
-{
-    return ((strcmp(arg, "-s") == 0) || (strcmp(arg, "--source") == 0));
-}
-
-static inline int is_option_target(char *arg)
-{
-    return ((strcmp(arg, "-t") == 0) || (strcmp(arg, "--target") == 0));
-}
-
-static int open_target_fs(int argc, char *argv[])
-{
-    printf("%-64s", "Opening target filesystem...");
-    int fd = -1;
-    for (int i = 1; i < argc; ++i) {
-        if (is_option_target(argv[i]) && ((i + 1) < argc)) {
-            fd = open(argv[i + 1], O_CREAT | O_RDWR, S_IRWXU | S_IRWXG | S_IRWXO);
-            break;
-        }
-    }
-    if (fd == -1)
-        printf("[" RED "FAILED" RESET "]\n\n");
-    else
-        printf("[" GREEN "DONE" RESET "]\n\n");
-    return fd;
-}
-
-static void init_headers(initrd_t *initrd)
-{
-    printf("%-64s", "Initializing headers structures...");
-    for (size_t i = 0; i < INITRD_MAX_FILES; i++) {
-        initrd->headers[i].magic     = 0xBF;
-        initrd->headers[i].inode     = i;
-        initrd->headers[i].file_type = 0;
-        initrd->headers[i].mask      = 0;
-        initrd->headers[i].uid       = 0;
-        initrd->headers[i].gid       = 0;
-        initrd->headers[i].atime     = time(NULL);
-        initrd->headers[i].mtime     = time(NULL);
-        initrd->headers[i].ctime     = time(NULL);
-        initrd->headers[i].offset    = 0;
-        initrd->headers[i].length    = 0;
-
-        memset(initrd->headers[i].name, 0, INITRD_NAME_MAX);
-    }
-    printf("[" GREEN "DONE" RESET "]\n\n");
-}
-
-static int create_file_headers(initrd_t *initrd, char *mountpoint, char *directory)
-{
-    assert(mountpoint && "Received null mountpoint.");
-    assert(directory && "Received null directory.");
-
-    // ------------------------------------------------------------------------
-    char directory_path_abs[PATH_MAX], entry_path_abs[PATH_MAX], fs_abs_path[PATH_MAX];
-    memset(directory_path_abs, 0, PATH_MAX);
-    memset(entry_path_abs, 0, PATH_MAX);
-    memset(fs_abs_path, 0, PATH_MAX);
-    strcpy(directory_path_abs, mountpoint);
-    strcat(directory_path_abs, directory);
-
-    int dir_fd = open(directory_path_abs, O_RDONLY);
-    if (dir_fd == -1) {
-        printf("[" RED "FAILED" RESET "]\n");
-        printf("Could not open source directory %s.\n", directory_path_abs);
-        return 0;
-    }
-
-    // ------------------------------------------------------------------------
-    char buffer[BUFSIZ], *ebuf;
-    off_t basep;
-    int nbytes;
-    while ((nbytes = getdirentries(dir_fd, buffer, BUFSIZ, &basep)) > 0) {
-        ebuf     = buffer + nbytes;
-        char *cp = buffer;
-        while (cp < ebuf) {
-            struct dirent *entry = (struct dirent *)cp;
-            if ((strcmp(entry->d_name, ".") == 0) || (strcmp(entry->d_name, "..") == 0)) {
-                cp += entry->d_reclen;
-                continue;
-            }
-            // Create the host machine absolute path.
-            strcpy(entry_path_abs, directory_path_abs);
-            strcat(entry_path_abs, "/");
-            strcat(entry_path_abs, entry->d_name);
-            // Create the filesystem absolute path.
-            strcpy(fs_abs_path, directory);
-            strcat(fs_abs_path, "/");
-            strcat(fs_abs_path, entry->d_name);
-            // Print the entry.
-            printf("[%3d] ENTRY: %-52s", initrd->nfiles, fs_abs_path);
-            // Stat the file.
-            struct stat _stat;
-            if (stat(entry_path_abs, &_stat) == -1) {
-                printf("[" RED "FAILED" RESET "]\n");
-                printf("Error while executing stat on file : %s\n", entry_path_abs);
-                return 0;
-            }
-            printf("[%c%c%c%c%c%c%c%c%c%c]",
-                   dt_char_array[entry->d_type],
-                   (_stat.st_mode & S_IRUSR) != 0 ? 'r' : '-',
-                   (_stat.st_mode & S_IWUSR) != 0 ? 'w' : '-',
-                   (_stat.st_mode & S_IXUSR) != 0 ? 'x' : '-',
-                   (_stat.st_mode & S_IRGRP) != 0 ? 'r' : '-',
-                   (_stat.st_mode & S_IWGRP) != 0 ? 'w' : '-',
-                   (_stat.st_mode & S_IXGRP) != 0 ? 'x' : '-',
-                   (_stat.st_mode & S_IROTH) != 0 ? 'r' : '-',
-                   (_stat.st_mode & S_IWOTH) != 0 ? 'w' : '-',
-                   (_stat.st_mode & S_IXOTH) != 0 ? 'x' : '-');
-
-            if (entry->d_type != DT_DIR) {
-                // ----------------------------------------------------------------
-                // Copy the name and the main info.
-                strcpy(initrd->headers[initrd->nfiles].name, fs_abs_path);
-                initrd->headers[initrd->nfiles].file_type = DT_REG;
-                initrd->headers[initrd->nfiles].length    = _stat.st_size;
-                initrd->headers[initrd->nfiles].offset    = fs_offset;
-                initrd->headers[initrd->nfiles].mask      = _stat.st_mode;
-                initrd->headers[initrd->nfiles].uid       = _stat.st_uid;
-                initrd->headers[initrd->nfiles].gid       = _stat.st_gid;
-                initrd->headers[initrd->nfiles].atime     = _stat.st_atim.tv_sec;
-                initrd->headers[initrd->nfiles].mtime     = _stat.st_mtim.tv_sec;
-                initrd->headers[initrd->nfiles].ctime     = _stat.st_ctim.tv_sec;
-
-                // ----------------------------------------------------------------
-                printf("[OFFSET:%6d]", initrd->headers[initrd->nfiles].offset);
-                printf("[SIZE:%6d]", initrd->headers[initrd->nfiles].length);
-                printf("[" GREEN "DONE" RESET "]\n");
-
-                fs_offset += initrd->headers[initrd->nfiles].length;
-                ++initrd->nfiles;
-            } else {
-                // ----------------------------------------------------------------
-                strcpy(initrd->headers[initrd->nfiles].name, fs_abs_path);
-                initrd->headers[initrd->nfiles].file_type = DT_DIR;
-                initrd->headers[initrd->nfiles].length    = _stat.st_size;
-                initrd->headers[initrd->nfiles].offset    = fs_offset;
-                initrd->headers[initrd->nfiles].mask      = _stat.st_mode;
-                initrd->headers[initrd->nfiles].uid       = _stat.st_uid;
-                initrd->headers[initrd->nfiles].gid       = _stat.st_gid;
-                initrd->headers[initrd->nfiles].atime     = _stat.st_atim.tv_sec;
-                initrd->headers[initrd->nfiles].mtime     = _stat.st_mtim.tv_sec;
-                initrd->headers[initrd->nfiles].ctime     = _stat.st_ctim.tv_sec;
-
-                // ----------------------------------------------------------------
-                printf("[OFFSET:%6d]", initrd->headers[initrd->nfiles].offset);
-                printf("[SIZE:%6d]", initrd->headers[initrd->nfiles].length);
-                printf("[" GREEN "DONE" RESET "]\n");
-
-                // ----------------------------------------------------------------
-                ++initrd->nfiles;
-
-                // ----------------------------------------------------------------
-                if (!create_file_headers(initrd, mountpoint, fs_abs_path)) {
-                    break;
-                }
-            }
-            cp += entry->d_reclen;
-        }
-    }
-    close(dir_fd);
-    return 1;
-}
-
-static int write_file_system(initrd_t *initrd, int target_fd, char *mountpoint)
-{
-    printf("Copying data to filesystem...\n");
-    for (int i = 0; i < INITRD_MAX_FILES; i++) {
-        // --------------------------------------------------------------------
-        char absolute_path[256];
-        memset(absolute_path, 0, 256);
-        strcpy(absolute_path, mountpoint);
-        strcat(absolute_path, initrd->headers[i].name);
-
-        // --------------------------------------------------------------------
-        if (initrd->headers[i].file_type == DT_REG) {
-            FILE *fd2 = fopen(absolute_path, "r+");
-            if (fd2 == NULL) {
-                continue;
-            }
-            printf("[%3d] FILE: %-92s", i, absolute_path);
-            char *buffer = (char *)malloc(initrd->headers[i].length);
-            fread(buffer, 1, initrd->headers[i].length, fd2);
-            // Write the content.
-            write(target_fd, buffer, initrd->headers[i].length);
-
-            printf("[" GREEN "DONE" RESET "]\n");
-            fclose(fd2);
-            free(buffer);
-        }
-    }
-    printf("[" GREEN "DONE" RESET "]\n\n");
-    return 1;
-}
-
-int main(int argc, char *argv[])
-{
-    printf("Welcome to MentOS initrd file copier tool\n\n");
-    if (argc <= 1) {
-        if (argv[0][0] == '.') {
-            version(argv[0] + 2);
-        }
-        usage(argv[0]);
-        return EXIT_FAILURE;
-    }
-    if (!strcmp(argv[1], "--version") || !strcmp(argv[1], "-v")) {
-        version(argv[0] + 2);
-        return EXIT_SUCCESS;
-    }
-    if (!strcmp(argv[1], "--help") || !strcmp(argv[1], "-h")) {
-        usage(argv[0]);
-        return EXIT_SUCCESS;
-    }
-
-    // Create the filesystem details structure.
-    initrd_t initrd;
-    // Target fs file descriptor.
-    int target_fd;
-
-    // ------------------------------------------------------------------------
-    // Open the fs.
-    if ((target_fd = open_target_fs(argc, argv)) == -1) {
-        printf("Could not open target FileSystem.\n");
-        return EXIT_FAILURE;
-    }
-
-    // ------------------------------------------------------------------------
-    // Initialize the headers.
-    init_headers(&initrd);
-
-    // ------------------------------------------------------------------------
-    // Create file headers.
-    printf("Creating headers...\n");
-    for (unsigned int i = 1; i < argc; ++i) {
-        if (is_option_source(argv[i]) && ((i + 1) < argc)) {
-            // ----------------------------------------------------------------
-            strcpy(initrd.headers[initrd.nfiles].name, "/");
-            initrd.headers[initrd.nfiles].file_type = DT_DIR;
-            initrd.headers[initrd.nfiles].length    = 0;
-            initrd.headers[initrd.nfiles].offset    = fs_offset;
-            initrd.headers[initrd.nfiles].mask      = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
-            initrd.headers[initrd.nfiles].uid       = 0;
-            initrd.headers[initrd.nfiles].gid       = 0;
-            initrd.headers[initrd.nfiles].atime     = time(NULL);
-            initrd.headers[initrd.nfiles].mtime     = time(NULL);
-            initrd.headers[initrd.nfiles].ctime     = time(NULL);
-
-            printf("[%3d] DIR : %-52s", initrd.nfiles, initrd.headers[initrd.nfiles].name);
-            printf("[" BLUE "OPEN" RESET "]");
-            printf("[OFFSET:%6d]", initrd.headers[initrd.nfiles].offset);
-            printf("[SIZE:%6d]", initrd.headers[initrd.nfiles].length);
-            printf("[" GREEN "DONE" RESET "]\n");
-            ++initrd.nfiles;
-
-            // ----------------------------------------------------------------
-            if (!create_file_headers(&initrd, argv[i + 1], "")) {
-                printf("Could not create file headers.\n");
-                close(target_fd);
-                return EXIT_FAILURE;
-            }
-        }
-    }
-    printf("[" GREEN "DONE" RESET "]\n\n");
-
-    // ------------------------------------------------------------------------
-    // Copying information about headers on filesystem.
-    printf("%-64s", "Copying the filesystem's details structure...");
-    write(target_fd, &initrd, sizeof(initrd_t));
-    printf("[" GREEN "DONE" RESET "]\n\n");
-
-    // ------------------------------------------------------------------------
-    // Write headers on filesystem.
-    for (unsigned int i = 1; i < argc; ++i) {
-        if (is_option_source(argv[i]) && ((i + 1) < argc)) {
-            if (!write_file_system(&initrd, target_fd, argv[i + 1])) {
-                printf("Could not write on filesystem.\n");
-                close(target_fd);
-                return EXIT_FAILURE;
-            }
-        }
-    }
-
-    // ------------------------------------------------------------------------
-    lseek(target_fd, 0L, SEEK_SET);
-    size_t fs_size = lseek(target_fd, 0L, SEEK_END);
-    printf("FS size : %ld\n", fs_size);
-    if (fs_size < INITRD_MAX_FS_SIZE - 1) {
-        printf("Extend FS size to : %d\n", INITRD_MAX_FS_SIZE - 1);
-        lseek(target_fd, INITRD_MAX_FS_SIZE - 1, SEEK_SET);
-        write(target_fd, 0, 1);
-    }
-    close(target_fd);
-    return 0;
-}

iso/boot/grub/grub.cfg

@@ -0,0 +1,7 @@
+set timeout=1
+set default=0
+
+menuentry "MentOS" {
+     multiboot /boot/kernel-bootloader.bin
+     boot
+}

libc/CMakeLists.txt

@@ -2,27 +2,20 @@
 # Author: Enrico Fraccaroli
 # =============================================================================
 # Set the minimum required version of cmake.
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.1...3.22)
 # Initialize the project.
 project(libc C ASM)
 
 # =============================================================================
-# Set the default build type to Debug.
+# ASSEMBLY
-if(NOT CMAKE_BUILD_TYPE)
-  message(STATUS "Setting build type to 'Debug' as none was specified.")
-  set(CMAKE_BUILD_TYPE
-      "Debug"
-      CACHE STRING "Choose the type of build." FORCE)
-endif()
-
 # =============================================================================
+
 # Enable the assembly language.
 enable_language(ASM)
 # Find the NASM compiler.
-find_program(ASM_COMPILER
+find_program(ASM_COMPILER NAMES nasm HINTS /usr/bin/ /usr/local/bin/)
-    NAMES nasm
+# Mark the variable ASM_COMPILER as advanced.
-    HINTS /usr/bin/ ${CMAKE_SOURCE_DIR}/third_party/nasm/bin
+mark_as_advanced(ASM_COMPILER)
-)
 # Check that we have found the compiler.
 if(NOT ASM_COMPILER)
     message(FATAL_ERROR "ASM compiler not found!")
@@ -42,25 +35,40 @@ elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
 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 "${CMAKE_C_FLAGS} -Werror")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
-#set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -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(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
+
-# Set the C compiler options.
+# Set the compiler options.
 set(CMAKE_C_FLAGS "${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} -ggdb")
     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")
@@ -89,24 +97,25 @@ add_library(
     ${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
@@ -129,7 +138,6 @@ add_library(
     ${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
 )
 

libc/inc/array.h

@@ -0,0 +1,38 @@
+/// @file array.h
+/// @brief
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+#ifdef __KERNEL__
+/// Function for allocating memory for the array.
+#define ARRAY_ALLOC kmalloc
+/// Function for freeing the memory for the array.
+#define ARRAY_FREE  kfree
+#else
+/// Function for allocating memory for the array.
+#define ARRAY_ALLOC malloc
+/// Function for freeing the memory for the array.
+#define ARRAY_FREE  free
+#endif
+
+/// @brief Declares a new dynamic-size array structure.
+#define DECLARE_ARRAY(type, name)                                                     \
+    typedef struct arr_##name##_t {                                                   \
+        const unsigned size;                                                          \
+        type *buffer;                                                                 \
+    } arr_##name##_t;                                                                 \
+    arr_##name##_t alloc_arr_##name(unsigned len)                                     \
+    {                                                                                 \
+        arr_##name##_t a = { len, len > 0 ? ARRAY_ALLOC(sizeof(type) * len) : NULL }; \
+        memset(a.buffer, 0, sizeof(type) * len);                                      \
+        return a;                                                                     \
+    }                                                                                 \
+    static inline void free_arr_##name(arr_##name##_t *arr)                           \
+    {                                                                                 \
+        ARRAY_FREE(arr->buffer);                                                      \
+    }
+
+#undef ARRAY_ALLOC malloc
+#undef ARRAY_FREE free

libc/inc/assert.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file assert.h
 /// @brief Defines the function and pre-processor macro for assertions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 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) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/bits/stat.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stat.h
 /// @brief Defines the structure used by the functiosn fstat(), lstat(), and stat().
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/bits/termios-struct.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file termios-struct.h
 /// @brief Definition of the `termios` structure.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -25,21 +24,23 @@ typedef struct termios {
     cc_t c_cc[NCCS];  ///< control characters
     speed_t c_ispeed; ///< input speed
     speed_t c_ospeed; ///< output speed
-} termios;
+} termios_t;
 
-/// @brief These flags generally control higher-level aspects of input processing than the input
+//These flags generally control higher-level aspects of input processing than
-/// modes flags described in Input Modes, such as echoing, signals, and the choice of canonical
+// the input modes flags described in Input Modes, such as echoing, signals, and
-/// or noncanonical input.
+// the choice of canonical or noncanonical input.
-enum {
+
-    ISIG    = 000001U, ///< Controls whether the INTR, QUIT, and SUSP characters are recognized.
+#define ISIG    0x00000080 ///< Controls whether the INTR, QUIT, and SUSP characters are recognized.
-    ICANON  = 000002U, ///< Enables canonical input processing mode.
+#define ICANON  0x00000100 ///< Enables canonical input processing mode.
-    ECHO    = 000010U, ///< Echo input characters.
+#define ECHO    0x00000008 ///< Echo input characters.
-    ECHOE   = 000020U, ///< If ICANON is set, the ERASE character erases the preceding character.
+#define ECHOE   0x00000002 ///< If ICANON is set, the ERASE character erases the preceding character.
-    ECHOK   = 000040U, ///< If ICANON is set, the KILL character erases the current line.
+#define ECHOK   0x00000004 ///< If ICANON is set, the KILL character erases the current line.
-    ECHONL  = 000100U, ///< If ICANON is set, echo the NL character even if ECHO is not set.
+#define ECHONL  0x00000010 ///< If ICANON is set, echo the NL character even if ECHO is not set.
-    NOFLSH  = 000200U, ///< Do not clear in/out queues when receiving INTR, QUIT, and SUSP.
+#define NOFLSH  0x80000000 ///< Do not clear in/out queues when receiving INTR, QUIT, and SUSP.
-    TOSTOP  = 000400U, ///< Allows SIGTTOU signals generated by background processes.
+#define TOSTOP  0x00400000 ///< Allows SIGTTOU signals generated by background processes.
-    ECHOCTL = 001000U, ///< If this and ECHO are set, control characters with ‘^’ are echoed.
+#define ECHOCTL 0x00000040 ///< If this and ECHO are set, control characters with ‘^’ are echoed.
-    ECHOKE  = 004000U, ///< If ICANON is set, KILL is echoed by erasing each character on the line.
+#define ECHOKE  0x00000001 ///< If ICANON is set, KILL is echoed by erasing each character on the line.
-    IEXTEN  = 100000U, ///< Enables implementation-defined input processing.
+#define IEXTEN  0x00000400 ///< Enables implementation-defined input processing.
-};
+
+/// @brief Mask for extracting control values.
+#define CTRL(x) (x & 037)

libc/inc/ctype.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file ctype.h
 /// @brief Functions related to character handling.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -16,6 +15,11 @@ int isdigit(int c);
 /// @return 1 on success, 0 otherwise.
 int isalpha(int c);
 
+/// @brief Check if the given value is a control character.
+/// @param c The input character.
+/// @return 1 on success, 0 otherwise.
+int iscntrl(int c);
+
 /// @brief Check if the given value is either a letter or a digit.
 /// @param c The input character.
 /// @return 1 on success, 0 otherwise.

libc/inc/debug.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file debug.h
 /// @brief Debugging primitives.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -36,9 +35,10 @@ void dbg_printf(const char *file, const char *fun, int line, const char *format,
 const char *to_human_size(unsigned long bytes);
 
 /// @brief Transforms the given value to a binary string.
-/// @param value The decimal value.
+/// @param value to print.
+/// @param length of the binary output.
 /// @return String representing the binary value.
-const char *dec_to_binary(unsigned long 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

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file fcntl.h
 /// @brief Headers of functions fcntl() and open().
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -20,20 +19,21 @@
 /// @brief The file modes.
 /// @{
 
-#define S_IRWXU 0000700U ///< RWX mask for user.
+#define S_ISUID 0x0800 ///< Set user id on execution
-#define S_IRUSR 0000400U ///< R for user.
+#define S_ISGID 0x0400 ///< Set group id on execution
-#define S_IWUSR 0000200U ///< W for user.
+#define S_ISVTX 0x0200 ///< Save swapped text even after use (Sticky Bit)
-#define S_IXUSR 0000100U ///< X for user.
+#define S_IRWXU 0x01C0 ///< rwx------- : User can read/write/execute
-
+#define S_IRUSR 0x0100 ///< -r-------- : User can read
-#define S_IRWXG 0000070U ///< RWX mask for group.
+#define S_IWUSR 0x0080 ///< --w------- : User can write
-#define S_IRGRP 0000040U ///< R for group.
+#define S_IXUSR 0x0040 ///< ---x------ : User can execute
-#define S_IWGRP 0000020U ///< W for group.
+#define S_IRWXG 0x0038 ///< ----rwx--- : Group can read/write/execute
-#define S_IXGRP 0000010U ///< X for group.
+#define S_IRGRP 0x0020 ///< ----r----- : Group can read
-
+#define S_IWGRP 0x0010 ///< -----w---- : Group can write
-#define S_IRWXO 0000007U ///< RWX mask for group.
+#define S_IXGRP 0x0008 ///< ------x--- : Group can execute
-#define S_IROTH 0000004U ///< R for group.
+#define S_IRWXO 0x0007 ///< -------rwx : Others can read/write/execute
-#define S_IWOTH 0000002U ///< W for group.
+#define S_IROTH 0x0004 ///< -------r-- : Others can read
-#define S_IXOTH 0000001U ///< X for group.
+#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

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file fcvt.h
 /// @brief Declare the functions required to turn double values into a string.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/grp.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file grp.h
 /// @brief Defines the structures and functions for managing groups.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -11,66 +10,63 @@
 /// Maximum number of users per group
 #define MAX_MEMBERS_PER_GROUP 64
 
-///@brief Contains user group informations
+/// @brief Contains user group informations.
-typedef struct group{
+typedef struct group {
+    /// The name of the group.
+    char *gr_name;
+    /// Encrypted password.
+    char *gr_passwd;
+    /// Group ID.
+    gid_t gr_gid;
+    /// List of group members.
+    char *gr_mem[MAX_MEMBERS_PER_GROUP + 1];
+} group_t;
 
-    char* gr_name;      // the name of the group
+/// @brief Provides access to the group database entry for `uid`.
-    gid_t gr_gid;       // numerical group ID
+/// @param gid The gid to search inside the database.
-    char* gr_passwd;    // password
+/// @return A pointer to the structure containing the database entry.
+group_t *getgrgid(gid_t gid);
 
-    //pointer to a null-terminated array of character pointers to member names
+/// @brief Provides access to the group database entry for `name`.
-    char* gr_mem[MAX_MEMBERS_PER_GROUP + 1];
+/// @param name The name to search inside the database.
-    
+/// @return A pointer to the structure containing the database entry.
-} group;
+group_t *getgrnam(const char *name);
 
-///@brief       Provides access to the group database entry for `uid`.
+/// @brief Provides the same information as getgrgid but it stores the results
-///@param gid   The gid to search inside the database.
+/// inside group, and the string information are store store inside `buf`.
-///@return      A pointer to the structure containing the database entry.
+/// @param gid The uid to search inside the database.
-struct group* getgrgid(gid_t gid);
+/// @param group The structure containing pointers to the entry fields.
+/// @param buf The buffer where the strings should be stored.
+/// @param buflen The lenght of the buffer.
+/// @param result A pointer to the result or NULL is stored here.
+/// @return If the entry was found returns zero and set *result to group, if the
+/// entry was not found returns zero and set *result to NULL, on failure returns
+/// a number and sets  and set *result to NULL.
+int getgrgid_r(gid_t gid, group_t *group, char *buf, size_t buflen, group_t **result);
 
-///@brief       Provides access to the group database entry for `name`.
+/// @brief Provides the same information as getgrnam but it stores the results
-///@param name  The name to search inside the database.
+///inside group, and the string information are store store inside `buf`.
-///@return      A pointer to the structure containing the database entry.
+/// @param name The name to search inside the database.
-struct group* getgrnam(const char* name);
+/// @param group The structure containing pointers to the entry fields.
+/// @param buf The buffer where the strings should be stored.
+/// @param buflen The lenght of the buffer.
+/// @param result A pointer to the result or NULL is stored here.
+/// @return If the entry was found returns zero and set *result to group, if the
+/// entry was not found returns zero and set *result to NULL, on failure returns
+/// a number and sets  and set *result to NULL.
+int getgrnam_r(const char *name, group_t *group, char *buf, size_t buflen, group_t **result);
 
-///@brief        Provides the same information as getgrgid but it stores the
+/// @brief Returns a pointer to a structure containing the broken-out fields of
-///              results inside group, and the string information are store store
+/// an entry in the group database.
-///              inside `buf`.
+/// @return pointer to the group entry.
-///@param gid    The uid to search inside the database.
+/// @details When first called returns a pointer to a group structure containing
-///@param group  The structure containing pointers to the entry fields.
+/// the first entry in the group database. Thereafter, it returns a pointer to a
-///@param buf    The buffer where the strings should be stored.
+/// group structure containing the next group structure in the group database,
-///@param buflen The lenght of the buffer.
+/// so successive calls may be used to search the entire database.
-///@param result A pointer to the result or NULL is stored here.
+group_t *getgrent(void);
-///@return       If the entry was found returns zero and set *result to group,
-///              if the entry was not found returns zero and set *result to NULL,
-///              on failure returns a number and sets  and set *result to NULL.
-int getgrgid_r(gid_t gid, struct group* group, char* buf, size_t buflen, struct group ** result);
 
-///@brief        Provides the same information as getgrnam but it stores the
+/// @brief Rewinds the group database to allow repeated searches.
-///              results inside group, and the string information are store store
-///              inside `buf`.
-///@param name   The name to search inside the database.
-///@param group  The structure containing pointers to the entry fields.
-///@param buf    The buffer where the strings should be stored.
-///@param buflen The lenght of the buffer.
-///@param result A pointer to the result or NULL is stored here.
-///@return       If the entry was found returns zero and set *result to group,
-///              if the entry was not found returns zero and set *result to NULL,
-///              on failure returns a number and sets  and set *result to NULL.
-int getgrnam_r(const char* name, struct group* group, char* buf, size_t buflen, struct group** result);
-
-
-///@brief Returns a pointer to a structure containing the broken-out 
-///       fields of an entry in the group database.
-///       When first called returns a pointer to a group structure 
-///       containing the first entry in the group database. 
-///       Thereafter, it returns a pointer to a group structure 
-///       containing the next group structure in the group database, 
-///       so successive calls may be used to search the entire database.
-struct group* getgrent(void);
-
-///@brief Rewinds the group database to allow repeated searches.
 void endgrent(void);
 
-///@brief May be called to close the group database when processing is complete.
+/// @brief May be called to close the group database when processing is complete.
 void setgrent(void);

libc/inc/io/mm_io.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file mm_io.h
 /// @brief Memory Mapped IO functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/io/port_io.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file port_io.h
 /// @brief Byte I/O on ports prototypes.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/ipc/ipc.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file ipc.h
 /// @brief Inter-Process Communication (IPC) structures.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/ipc/msg.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file msg.h
 /// @brief Definition of structure for managing message queues.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -18,15 +17,15 @@ typedef unsigned int msgqnum_t;
 typedef unsigned int msglen_t;
 
 /// @brief Buffer to use with the message queue IPC.
-struct msgbuf {
+typedef struct msgbuf {
     /// Type of the message.
     long mtype;
     /// Text of the message.
     char mtext[1];
-};
+} msgbuf_t;
 
 /// @brief Message queue data structure.
-struct msqid_ds {
+typedef struct msqid_ds {
     /// Ownership and permissions.
     struct ipc_perm msg_perm;
     /// Time of last msgsnd(2).
@@ -45,26 +44,82 @@ struct msqid_ds {
     pid_t msg_lspid;
     /// PID of last msgrcv(2).
     pid_t msg_lrpid;
-};
+} msqid_ds_t;
 
 #ifdef __KERNEL__
 
+/// @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);
 
-long sys_msgsnd(int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg);
+/// @brief Used to send messages.
+/// @param msqid the message queue identifier.
+/// @param msgp points to a used-defined msgbuf.
+/// @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);
 
-long sys_msgrcv(int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp, int msgflg);
+/// @brief Used to receive messages.
+/// @param msqid the message queue identifier.
+/// @param msgp points to a used-defined msgbuf.
+/// @param msgsz specifies the size in bytes of mtext.
+/// @param msgtyp specifies the type of message requested, as follows:
+/// - msgtyp == 0: the first message on the queue is received.
+/// - msgtyp  > 0: the first message of type, msgtyp, is received.
+/// - 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);
 
-long sys_msgctl(int msqid, int cmd, struct msqid_ds *buf);
+/// @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);
 
 #else
 
+/// @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 msgget(key_t key, int msgflg);
 
-long msgsnd(int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg);
+/// @brief Used to send messages.
+/// @param msqid the message queue identifier.
+/// @param msgp points to a used-defined msgbuf.
+/// @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);
 
-long msgrcv(int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp, int msgflg);
+/// @brief Used to receive messages.
+/// @param msqid the message queue identifier.
+/// @param msgp points to a used-defined msgbuf.
+/// @param msgsz specifies the size in bytes of mtext.
+/// @param msgtyp specifies the type of message requested, as follows:
+/// - msgtyp == 0: the first message on the queue is received.
+/// - msgtyp  > 0: the first message of type, msgtyp, is received.
+/// - 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);
 
-long msgctl(int msqid, int cmd, struct msqid_ds *buf);
+/// @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);
 
 #endif

libc/inc/ipc/sem.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file sem.h
 /// @brief Definition of structure for managing semaphores.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -23,18 +22,54 @@ struct sembuf {
 
 #ifdef __KERNEL__
 
+/// @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.
+/// @param nsems number of semaphores.
+/// @param semflg controls the behaviour of the function.
+/// @return the semaphore set identifier, -1 on failure, and errno is set to
+/// indicate the error.
 long sys_semget(key_t key, int nsems, int semflg);
 
+/// @brief Performs operations on selected semaphores in the set.
+/// @param semid the semaphore set identifier.
+/// @param sops specifies operations to be performed on single semaphores.
+/// @param nsops number of operations.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 long sys_semop(int semid, struct sembuf *sops, unsigned nsops);
 
+/// @brief Performs control operations on a semaphore set.
+/// @param semid the semaphore set identifier.
+/// @param semnum the n-th semaphore of the set on which we perform the operations.
+/// @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);
 
 #else
 
+/// @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.
+/// @param nsems number of semaphores.
+/// @param semflg controls the behaviour of the function.
+/// @return the semaphore set identifier, -1 on failure, and errno is set to
+/// indicate the error.
 long semget(key_t key, int nsems, int semflg);
 
+/// @brief Performs operations on selected semaphores in the set.
+/// @param semid the semaphore set identifier.
+/// @param sops specifies operations to be performed on single semaphores.
+/// @param nsops number of operations.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 long semop(int semid, struct sembuf *sops, unsigned nsops);
 
+/// @brief Performs control operations on a semaphore set.
+/// @param semid the semaphore set identifier.
+/// @param semnum the n-th semaphore of the set on which we perform the operations.
+/// @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);
 
 #endif

libc/inc/ipc/shm.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file shm.h
 /// @brief Definition of structure for managing shared memories.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -136,22 +135,72 @@ struct shmid_ds *find_shm_fromvaddr(void *shmvaddr);
 
 #ifdef __KERNEL__
 
-long sys_shmat(int shmid, char *shmaddr, int shmflg);
+/// @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.
+/// @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_shmdt(char *shmaddr);
+/// @brief Attaches the shared memory segment identified by shmid to the address
+/// space of the calling process.
+/// @param shmid the shared memory identifier.
+/// @param shmaddr the attaching address.
+/// @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);
 
+/// @brief Detaches the shared memory segment located at the address specified
+/// by shmaddr from the address space of the calling process
+/// @param shmaddr the address of the shared memory segment.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
+long sys_shmdt(const void *shmaddr);
+
+/// @brief Performs the control operation specified by cmd on the shared memory
+/// segment whose identifier is given in shmid.
+/// @param shmid the shared memory identifier.
+/// @param cmd the command to perform.
+/// @param buf is a pointer to a shmid_ds structure.
+/// @return a non-negative value basedon on the requested operation, -1 on
+/// failure and errno is set to indicate the error.
 long sys_shmctl(int shmid, int cmd, struct shmid_ds *buf);
 
 #else
 
-long shmat(int shmid, char *shmaddr, int shmflg);
+/// @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.
+/// @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 shmdt(char *shmaddr);
+/// @brief Attaches the shared memory segment identified by shmid to the address
+/// space of the calling process.
+/// @param shmid the shared memory identifier.
+/// @param shmaddr the attaching address.
+/// @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);
 
+/// @brief Detaches the shared memory segment located at the address specified
+/// by shmaddr from the address space of the calling process
+/// @param shmaddr the address of the shared memory segment.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
+long shmdt(const void *shmaddr);
+
+/// @brief Performs the control operation specified by cmd on the shared memory
+/// segment whose identifier is given in shmid.
+/// @param shmid the shared memory identifier.
+/// @param cmd the command to perform.
+/// @param buf is a pointer to a shmid_ds structure.
+/// @return a non-negative value basedon on the requested operation, -1 on
+/// failure and errno is set to indicate the error.
 long shmctl(int shmid, int cmd, struct shmid_ds *buf);
 
 #endif

libc/inc/libgen.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file libgen.h
 /// @brief String routines.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "stddef.h"

libc/inc/limits.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file limits.h
 /// @brief OS numeric limits.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/math.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file math.h
 /// @brief Mathematical constants and functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/pwd.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file pwd.h
 /// @brief Contains the structure and functions for managing passwords.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/ring_buffer.h

@@ -0,0 +1,127 @@
+/// @file ring_buffer.h
+/// @brief
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+/// @brief Declares a fixed-size ring-buffer.
+#define DECLARE_FIXED_SIZE_RING_BUFFER(type, name, length, init)                     \
+    typedef struct fs_rb_##name##_t {                                                \
+        unsigned size, read, write;                                                  \
+        type buffer[length];                                                         \
+    } fs_rb_##name##_t;                                                              \
+    static inline void fs_rb_##name##_init(fs_rb_##name##_t *rb)                     \
+    {                                                                                \
+        rb->size = length;                                                           \
+        rb->read = rb->write = 0;                                                    \
+        char *dst            = (char *)rb->buffer;                                   \
+        long num             = sizeof(type) * length;                                \
+        while (num--) *dst++ = (char)(init & 0xFF);                                  \
+    }                                                                                \
+    static inline unsigned fs_rb_##name##_step(fs_rb_##name##_t *rb, unsigned index) \
+    {                                                                                \
+        return (index == (rb->size - 1)) ? 0 : index + 1;                            \
+    }                                                                                \
+    static inline void fs_rb_##name##_push_front(fs_rb_##name##_t *rb, type item)    \
+    {                                                                                \
+        if (fs_rb_##name##_step(rb, rb->write) == rb->read)                          \
+            rb->read = fs_rb_##name##_step(rb, rb->read);                            \
+        rb->buffer[rb->write] = item;                                                \
+        rb->write             = fs_rb_##name##_step(rb, rb->write);                  \
+    }                                                                                \
+    static inline type fs_rb_##name##_empty(fs_rb_##name##_t *rb)                    \
+    {                                                                                \
+        return rb->write == rb->read;                                                \
+    }                                                                                \
+    static inline type fs_rb_##name##_pop_back(fs_rb_##name##_t *rb)                 \
+    {                                                                                \
+        type item = init;                                                            \
+        if (!fs_rb_##name##_empty(rb)) {                                             \
+            item     = rb->buffer[rb->read];                                         \
+            rb->read = fs_rb_##name##_step(rb, rb->read);                            \
+        }                                                                            \
+        return item;                                                                 \
+    }                                                                                \
+    static inline type fs_rb_##name##_pop_front(fs_rb_##name##_t *rb)                \
+    {                                                                                \
+        if (fs_rb_##name##_empty(rb))                                                \
+            return init;                                                             \
+        rb->write = (rb->write > 0) ? rb->write - 1 : rb->size - 1;                  \
+        return rb->buffer[rb->write];                                                \
+    }                                                                                \
+    static inline type fs_rb_##name##_get(fs_rb_##name##_t *rb, unsigned index)      \
+    {                                                                                \
+        if (index < rb->size)                                                        \
+            return rb->buffer[index];                                                \
+        return init;                                                                 \
+    }                                                                                \
+    static inline type fs_rb_##name##_back(fs_rb_##name##_t *rb)                     \
+    {                                                                                \
+        if (fs_rb_##name##_empty(rb))                                                \
+            return init;                                                             \
+        return rb->buffer[rb->read];                                                 \
+    }                                                                                \
+    static inline type fs_rb_##name##_front(fs_rb_##name##_t *rb)                    \
+    {                                                                                \
+        if (fs_rb_##name##_empty(rb))                                                \
+            return init;                                                             \
+        return rb->buffer[(rb->write > 0) ? rb->write - 1 : rb->size - 1];           \
+    }
+
+#ifdef __KERNEL__
+/// Function for allocating memory for the ring buffer.
+#define RING_BUFFER_ALLOC kmalloc
+/// Function for freeing the memory for the ring buffer.
+#define RING_BUFFER_FREE  kfree
+#else
+/// Function for allocating memory for the ring buffer.
+#define RING_BUFFER_ALLOC malloc
+/// Function for freeing the memory for the ring buffer.
+#define RING_BUFFER_FREE  free
+#endif
+
+/// @brief Declares a dynamic-size ring-buffer.
+#define DECLARE_RING_BUFFER(type, name, init)                                                       \
+    typedef struct rb_##name##_t {                                                                  \
+        const unsigned size;                                                                        \
+        unsigned read, write;                                                                       \
+        type *buffer;                                                                               \
+    } rb_##name##_t;                                                                                \
+    static inline rb_##name##_t alloc_rb_##name(unsigned len)                                       \
+    {                                                                                               \
+        rb_##name##_t rb = { len, 0U, 0U, len > 0 ? RING_BUFFER_ALLOC(sizeof(type) * len) : NULL }; \
+        memset(rb.buffer, init, sizeof(type) * len);                                                \
+        return rb;                                                                                  \
+    }                                                                                               \
+    static inline void free_rb_##name(rb_##name##_t *rb)                                            \
+    {                                                                                               \
+        RING_BUFFER_FREE(rb->buffer);                                                               \
+    }                                                                                               \
+    static inline unsigned step_rb_##name(rb_##name##_t *rb, unsigned index)                        \
+    {                                                                                               \
+        return (index == (rb->size - 1)) ? 0 : index + 1;                                           \
+    }                                                                                               \
+    static inline void push_rb_##name(rb_##name##_t *rb, type item)                                 \
+    {                                                                                               \
+        if (step_rb_##name(rb, rb->write) == rb->read)                                              \
+            rb->read = step_rb_##name(rb, rb->read);                                                \
+        rb->buffer[rb->write] = item;                                                               \
+        rb->write             = step_rb_##name(rb, rb->write);                                      \
+    }                                                                                               \
+    static inline void pop_rb_##name(rb_##name##_t *rb, type *item)                                 \
+    {                                                                                               \
+        *item = init;                                                                               \
+        if (rb->write != rb->read) {                                                                \
+            *item    = rb->buffer[rb->read];                                                        \
+            rb->read = step_rb_##name(rb, rb->read);                                                \
+        }                                                                                           \
+    }                                                                                               \
+    static inline void get_rb_##name(rb_##name##_t *rb, unsigned index, type *item)                 \
+    {                                                                                               \
+        if (index < rb->size)                                                                       \
+            *item = rb->buffer[index];                                                              \
+    }
+
+#undef RING_BUFFER_ALLOC
+#undef RING_BUFFER_FREE

libc/inc/sched.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file sched.h
 /// @brief Structures and functions for managing the scheduler.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/types.h"
@@ -22,8 +21,23 @@ typedef struct sched_param_t {
     bool_t is_periodic;
 } sched_param_t;
 
+/// @brief Sets scheduling parameters.
+/// @param pid pid of the process we want to change the parameters. If zero,
+/// then the parameters of the calling process are set.
+/// @param param The interpretation of the argument param depends on the
+/// scheduling policy of the thread identified by pid.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 int sched_setparam(pid_t pid, const sched_param_t *param);
 
+/// @brief Gets scheduling parameters.
+/// @param pid pid of the process we want to retrieve the parameters. If zero,
+/// then the parameters of the calling process are returned.
+/// @param param The interpretation of the argument param depends on the
+/// scheduling policy of the thread identified by pid.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 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();

libc/inc/signal.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file signal.h
 /// @brief Signals definition.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdarg.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stdarg.h
 /// @brief Contains the macros required to manage variable number of arguments.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdbool.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stdbool.h
 /// @brief Defines the boolean values.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stddef.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stddef.h
 /// @brief Define basic data types.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdint.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stdint.h
 /// @brief Standard integer data-types.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/stdio.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stdio.h
 /// @brief Standard I/0 functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -23,6 +22,7 @@
 #define SEEK_CUR 1 ///< The file offset is set to its current location plus offset bytes.
 #define SEEK_END 2 ///< The file offset is set to the size of the file plus offset bytes.
 
+#ifndef __KERNEL__
 /// @brief Writes the given character to the standard output (stdout).
 /// @param character The character to send to stdout.
 void putchar(int character);
@@ -41,7 +41,6 @@ int getchar();
 /// @return The string received from standard input.
 char *gets(char *str);
 
-#ifndef __KERNEL__
 /// @brief Same as getchar but reads from the given file descriptor.
 /// @param fd The file descriptor from which it reads.
 /// @return The read character.
@@ -108,7 +107,6 @@ int vsprintf(char *str, const char *fmt, va_list args);
 /// @return On success, the function returns the number of items of the
 ///         argument list successfully filled. EOF otherwise.
 int scanf(const char *fmt, ...);
-#endif
 
 /// @brief Read formatted data from string.
 /// @param str String processed as source to retrieve the data.
@@ -118,7 +116,6 @@ int scanf(const char *fmt, ...);
 ///         argument list successfully filled. EOF otherwise.
 int sscanf(const char *str, const char *fmt, ...);
 
-#ifndef __KERNEL__
 /// @brief The same as sscanf but the source is a file.
 /// @param fd  The file descriptor associated with the file.
 /// @param fmt  Format string, following the same specifications as printf.

libc/inc/stdlib.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stdlib.h
 /// @brief Useful generic functions and macros.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/strerror.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file strerror.h
 /// @brief Contains the function that transfornms an errno into a string.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/string.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file string.h
 /// @brief String routines.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/bitops.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file bitops.h
 /// @brief Bitmasks functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/dirent.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file dirent.h
 /// @brief Functions used to manage directories.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/errno.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file errno.h
 /// @brief System call errors definition.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/ioctl.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file ioctl.h
 /// @brief Input/Output ConTroL (IOCTL) functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/reboot.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file reboot.h
 /// @brief Defines the values required to issue a reboot.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/stat.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stat.h
 /// @brief Stat functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -32,4 +31,12 @@ int mkdir(const char *path, mode_t mode);
 /// @brief Removes the given directory.
 /// @param path The path to the directory to remove.
 /// @return Returns a negative value on failure.
-int rmdir(const char *path);
+int rmdir(const char *path);
+
+/// @brief Creates a new file or rewrite an existing one.
+/// @param path path to the file.
+/// @param mode mode for file creation.
+/// @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);

libc/inc/sys/types.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file types.h
 /// @brief Collection of Kernel datatype
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/unistd.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file unistd.h
 /// @brief Functions used to manage files.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -28,14 +27,11 @@ ssize_t read(int fd, void *buf, size_t nbytes);
 /// @return       The number of written bytes.
 ssize_t write(int fd, void *buf, size_t nbytes);
 
-/// @brief          Opens the file specified by pathname.
+/// @brief Opens the file specified by pathname.
 /// @param pathname A pathname for a file.
-/// @param flags    Used to set the file status flags and file access modes
+/// @param flags file status flags and file access modes of the open file description.
-///                 of the open file description.
+/// @param mode the file mode bits be applied when a new file is created.
-/// @param mode     Specifies the file mode bits be applied when a new file
+/// @return file descriptor number, -1 otherwise and errno is set to indicate the error.
-///                 is created.
-/// @return         Returns a file descriptor, a small, nonnegative integer for
-///                 use in subsequent system calls.
 int open(const char *pathname, int flags, mode_t mode);
 
 /// @brief Close a file descriptor.
@@ -84,6 +80,19 @@ extern pid_t getsid(pid_t pid);
 ///        Otherwise return -1 with errno : EPERM 
 extern pid_t setsid();
 
+///@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.
+/// @param pid process of which we want to know the PGID.
+/// @return the PGID of the specified process.
+pid_t getpgid(pid_t pid);
+
+/// @brief Sets the Process Group ID (PGID) of the process specified by pid.
+/// If pid is zero, the process ID of the calling process is used.
+/// @param pid process of which we want to set the PGID.
+/// @param pgid the PGID we want to set.
+/// @return returns zero. On error, -1 is returned, and errno is set appropriately.
+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();
@@ -94,6 +103,16 @@ extern pid_t getgid();
 ///        Otherwise returns -1 with errno set to :EINVAL or EPERM  
 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();
+
+///@brief Sets the effective User ID of the calling process.
+///@param uid the new User ID.
+///@return On success, zero is returned.
+///        Otherwise returns -1 with errno set to :EINVAL or EPERM  
+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();
@@ -203,11 +222,13 @@ char *getcwd(char *buf, size_t size);
 
 /// @brief Changes the current working directory to the given path.
 /// @param path The new current working directory.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 int chdir(char const *path);
 
 /// @brief Is identical to chdir(), the only difference is that the
 ///        directory is given as an open file descriptor.
 /// @param fd The file descriptor of the open directory.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 int fchdir(int fd);
 
 /// Provide access to the directory entries.
@@ -220,4 +241,9 @@ int fchdir(int fd);
 int getdents(int fd, dirent_t *dirp, unsigned int count);
 
 /// @brief Send signal to calling thread after desired seconds.
+/// @param seconds the amount of seconds.
+/// @return If there is a previous alarm() request with time remaining, alarm()
+/// 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);

libc/inc/sys/utsname.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file utsname.h
 /// @brief Functions used to provide information about the machine & OS.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/sys/wait.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file wait.h
 /// @brief Event management functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/system/syscall_types.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file syscall_types.h
 /// @brief System Call numbers.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once

libc/inc/termios.h

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file termios.h
 /// @brief Defines the termios functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
@@ -12,11 +11,11 @@
 /// @param fd
 /// @param termios_p
 /// @return
-extern int tcgetattr(int fd, termios *termios_p);
+extern int tcgetattr(int fd, termios_t *termios_p);
 
 /// @brief Set the state of FD to *TERMIOS_P.
 /// @param fd
 /// @param optional_actions
 /// @param termios_p
 /// @return
-extern int tcsetattr(int fd, int optional_actions, const termios *termios_p);
+extern int tcsetattr(int fd, int optional_actions, const termios_t *termios_p);

libc/inc/time.h

@@ -1,17 +1,22 @@
-///                MentOS, The Mentoring Operating system project
 /// @file time.h
 /// @brief Time-related functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #pragma once
 
 #include "stddef.h"
 
-/// Domains of interval timers
+/// @brief This timer counts down in real (i.e., wall clock) time. At each
-#define ITIMER_REAL    0
+/// expiration, a SIGALRM signal is generated.
+#define ITIMER_REAL 0
+/// @brief This timer counts down against the user-mode CPU time consumed by the
+/// process. At each expiration, a SIGVTALRM signal is generated.
 #define ITIMER_VIRTUAL 1
-#define ITIMER_PROF    2
+/// @brief This timer counts down against the total (i.e., both user and system)
+/// CPU time consumed by the process. At each expiration, a SIGPROF signal is
+/// generated.
+#define ITIMER_PROF 2
 
 /// Used to store time values.
 typedef unsigned int time_t;
@@ -38,16 +43,16 @@ typedef struct tm_t {
     int tm_isdst;
 } tm_t;
 
-/// Rappresents time
+/// Rappresents time.
 typedef struct _timeval {
-    time_t tv_sec;  /* seconds */
+    time_t tv_sec;  ///< Seconds.
-    time_t tv_usec; /* microseconds */
+    time_t tv_usec; ///< Microseconds.
 } timeval;
 
-/// Rappresents a time interval
+/// Rappresents a time interval.
 typedef struct _itimerval {
-    timeval it_interval; /* next value */
+    timeval it_interval; ///< Next value.
-    timeval it_value;    /* current value */
+    timeval it_value;    ///< Current value.
 } itimerval;
 
 /// @brief Specify intervals of time with nanosecond precision.
@@ -102,9 +107,18 @@ int nanosleep(const timespec *req, timespec *rem);
 ///         left to sleep, if the call was interrupted by a signal handler.
 unsigned int sleep(unsigned int seconds);
 
-/// @brief Fills the structure pointed to by curr_value with the current setting for the timer specified by which.
+/// @brief Fills the structure pointed to by curr_value with the current setting
+/// for the timer specified by which.
+/// @param which which timer.
+/// @param curr_value where we place the timer value.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 int getitimer(int which, itimerval *curr_value);
 
-/// @brief The system provides each process with three interval timers, each decrementing in a distinct time domain. 
+/// @brief The system provides each process with three interval timers, each
-///        When any timer expires, a signal is sent to the process, and the timer (potentially) restarts.
+/// decrementing in a distinct time domain. When any timer expires, a signal is
+/// sent to the process, and the timer (potentially) restarts.
+/// @param which which timer.
+/// @param new_value the new value for the timer.
+/// @param old_value output variable where the function places the previous value.
+/// @return 0 on success, -1 on failure and errno is set to indicate the error.
 int setitimer(int which, const itimerval *new_value, itimerval *old_value);

libc/src/abort.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file abort.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/unistd.h"

libc/src/assert.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file assert.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "assert.h"

libc/src/ctype.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file ctype.c
 /// @brief Functions related to character handling.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "ctype.h"
@@ -19,6 +18,11 @@ int isalpha(int c)
     return ((c >= 65 && c <= 90) || (c >= 97 && c <= 122));
 }
 
+int iscntrl(int c)
+{
+    return ((c >= 0x00 && c <= 0x1F) || (c == 0x7F));
+}
+
 int isalnum(int c)
 {
     return (isalpha(c) || isdigit(c));

libc/src/debug.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file   debug.c
 /// @brief  Debugging primitives.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include <debug.h>
@@ -11,35 +10,39 @@
 #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)
 {
-#if (defined(DEBUG_STDIO) || defined(DEBUG_LOG))
     outportb(SERIAL_COM1, (uint8_t)c);
-#endif
 }
 
 void dbg_puts(const char *s)
 {
-#if (defined(DEBUG_STDIO) || defined(DEBUG_LOG))
     while ((*s) != 0)
         dbg_putchar(*s++);
-#endif
 }
 
 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);
+    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, ...)
@@ -96,10 +99,10 @@ const char *to_human_size(unsigned long bytes)
     return output;
 }
 
-const char *dec_to_binary(unsigned long value)
+const char *dec_to_binary(unsigned long value, unsigned length)
 {
     static char buffer[33];
-    for (int i = 0; i < 32; ++i)
+    for (int i = 0, j = 32 - min(max(0, length), 32); j < 32; ++i, ++j)
-        buffer[i] = bit_check(value, 31 - i) ? '1' : '0';
+        buffer[i] = bit_check(value, 31 - j) ? '1' : '0';
     return buffer;
 }

libc/src/fcvt.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file fcvt.c
 /// @brief Define the functions required to turn double values into a string.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "fcvt.h"

libc/src/grp.c

@@ -1,10 +1,9 @@
-///                MentOS, The Mentoring Operating system project
 /// @file grp.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include "grp.h"  
+#include "grp.h"
 #include "sys/unistd.h"
 #include "sys/errno.h"
 #include "assert.h"
@@ -13,8 +12,9 @@
 #include "debug.h"
 #include "fcntl.h"
 
+static int __fd = -1;
 
-static inline void __parse_line(struct group* grp, char *buf)
+static inline void __parse_line(group_t *grp, char *buf)
 {
     assert(grp && "Received null grp!");
     char *token;
@@ -29,7 +29,7 @@ static inline void __parse_line(struct group* grp, char *buf)
         grp->gr_gid = atoi(token);
 
     size_t found_users = 0;
-    while((token = strtok(NULL, ",\n\0")) != NULL && found_users < MAX_MEMBERS_PER_GROUP) {
+    while ((token = strtok(NULL, ",\n\0")) != NULL && found_users < MAX_MEMBERS_PER_GROUP) {
         grp->gr_mem[found_users] = token;
         found_users += 1;
     }
@@ -90,45 +90,44 @@ static inline char *__search_entry(int fd, char *buf, int buflen, const char *na
     return NULL;
 }
 
-struct group* getgrgid(gid_t gid) {
+group_t *getgrgid(gid_t gid)
-
+{
-    static group grp;
+    static group_t grp;
     static char buffer[BUFSIZ];
 
-    group *result;
+    group_t *result;
     if (!getgrgid_r(gid, &grp, buffer, BUFSIZ, &result))
         return NULL;
 
     return &grp;
 }
 
-struct group *getgrnam(const char* name) {
+group_t *getgrnam(const char *name)
-    
+{
     if (name == NULL)
         return NULL;
 
-    static group grp;
+    static group_t grp;
     static char buffer[BUFSIZ];
 
-    group *result;
+    group_t *result;
     if (!getgrnam_r(name, &grp, buffer, BUFSIZ, &result))
         return NULL;
 
     return &grp;
 }
 
-int getgrgid_r(gid_t gid, struct group* group, char* buf, size_t buflen, struct group ** result) {
+int getgrgid_r(gid_t gid, group_t *group, char *buf, size_t buflen, group_t **result)
-    
+{
     int fd = open("/etc/group", O_RDONLY, 0);
     if (fd == -1) {
         errno   = ENOENT;
         *result = NULL;
         return 0;
     }
-    
+
     char *entry = __search_entry(fd, buf, buflen, NULL, gid);
     if (entry != NULL) {
-
         // Close the file.
         close(fd);
         // Parse the line.
@@ -143,18 +142,17 @@ int getgrgid_r(gid_t gid, struct group* group, char* buf, size_t buflen, struct
     return 0;
 }
 
-int getgrnam_r(const char* name, struct group* group, char* buf, size_t buflen, struct group** result) {
+int getgrnam_r(const char *name, group_t *group, char *buf, size_t buflen, group_t **result)
-
+{
     int fd = open("/etc/group", O_RDONLY, 0);
     if (fd == -1) {
         errno   = ENOENT;
         *result = NULL;
         return 0;
     }
-    
+
     char *entry = __search_entry(fd, buf, buflen, name, 0);
     if (entry != NULL) {
-
         // Close the file.
         close(fd);
         // Parse the line.
@@ -169,15 +167,14 @@ int getgrnam_r(const char* name, struct group* group, char* buf, size_t buflen,
     return 0;
 }
 
-static int fd = -1;
+group_t *getgrent(void)
-struct group* getgrent(void) {
+{
+    static group_t result;
 
-    static group result;
+    if (__fd == -1) {
-
-    if (fd == -1) {
         //pr_debug("Opening group file\n");
-        fd = open("/etc/group", O_RDONLY, 0);
+        __fd = open("/etc/group", O_RDONLY, 0);
-        if (fd == -1) {
+        if (__fd == -1) {
             errno = ENOENT;
             return 0;
         }
@@ -188,8 +185,7 @@ struct group* getgrent(void) {
     int pos = 0;
 
     static char buffer[BUFSIZ];
-    while ((ret = read(fd, &c, 1U))) {
+    while ((ret = read(__fd, &c, 1U))) {
-
         // Skip carriage return.
         if (c == '\r')
             continue;
@@ -224,15 +220,15 @@ struct group* getgrent(void) {
     return NULL;
 }
 
-void endgrent(void) {
+void endgrent(void)
-
+{
     //pr_debug("Closing group file\n");
-    close(fd);
+    close(__fd);
-    fd = -1;
+    __fd = -1;
 }
 
-void setgrent(void) {
+void setgrent(void)
-
+{
     //pr_debug("Resetting pointer to beginning of group file\n");
-    lseek(fd, 0, SEEK_SET);
+    lseek(__fd, 0, SEEK_SET);
 }

libc/src/io/mm_io.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file mm_io.c
 /// @brief Memory Mapped IO functions implementation.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "io/mm_io.h"

libc/src/io/port_io.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file port_io.c
 /// @brief Byte I/O on ports prototypes.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "io/port_io.h"

libc/src/ipc/ipc.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file ipc.c
 /// @brief Inter-Process Communication (IPC) system call implementation.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/unistd.h"
@@ -12,11 +11,11 @@
 #include "ipc/shm.h"
 #include "ipc/msg.h"
 
-_syscall3(long, shmat, int, shmid, char *, shmaddr, int, shmflg)
+_syscall3(void *, shmat, int, shmid, const void *, shmaddr, int, shmflg)
 
 _syscall3(long, shmget, key_t, key, size_t, size, int, flag)
 
-_syscall1(long, shmdt, char *, shmaddr)
+_syscall1(long, shmdt, const void *, shmaddr)
 
 _syscall3(long, shmctl, int, shmid, int, cmd, struct shmid_ds *, buf)
 

libc/src/libc_start.c

@@ -1,5 +1,7 @@
 /// @file libc_start.c
 /// @brief Contains the programs initialization procedure.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
 
 #include "sys/unistd.h"
 #include "stdlib.h"
@@ -33,8 +35,3 @@ int __libc_start_main(int (*main)(int, char **, char **), int argc, char *argv[]
     //dbg_print("== END   %-30s =======================================\n", argv[0]);
     return result;
 }
-
-// WARNING: This declaration must be here, because libc_start is compiled
-// with all the programs, and all the programs NEED to have the `sigreturn`
-// symbol. It must be this way, period.
-_syscall0(int, sigreturn)

libc/src/libgen.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file libgen.c
 /// @brief String routines.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include <assert.h>

libc/src/math.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file math.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "math.h"

libc/src/pwd.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file pwd.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "pwd.h"
@@ -11,11 +10,12 @@
 #include "string.h"
 #include "stdio.h"
 #include "fcntl.h"
+#include "debug.h"
 
 static inline void __parse_line(passwd_t *pwd, char *buf)
 {
     assert(pwd && "Received null pwd!");
-    char *token;
+    char *token, *ch;
     // Parse the username.
     if ((token = strtok(buf, ":")) != NULL)
         pwd->pw_name = token;
@@ -35,59 +35,88 @@ static inline void __parse_line(passwd_t *pwd, char *buf)
     if ((token = strtok(NULL, ":")) != NULL)
         pwd->pw_dir = token;
     // Parse the shell.
-    if ((token = strtok(NULL, ":")) != NULL)
+    if ((token = strtok(NULL, ":")) != NULL) {
         pwd->pw_shell = token;
+        // Find carriege return.
+        if ((ch = strchr(pwd->pw_shell, '\r')))
+            *ch = 0;
+        // Find newline.
+        if ((ch = strchr(pwd->pw_shell, '\n')))
+            *ch = 0;
+    }
 }
 
-static inline char *__search_entry(int fd, char *buf, int buflen, const char *name, uid_t uid)
+/// @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)
 {
-    int ret;
+    memset(buffer, 0, buflen);
-    char c;
+    long num_read = read(fd, buffer, buflen);
-    int pos = 0;
+    if (num_read == 0) {
-    while ((ret = read(fd, &c, 1U))) {
+        return 0;
-        // Skip carriage return.
+    }
-        if (c == '\r')
+    char *newline = strchr(buffer, '\n');
-            continue;
+    if (newline == NULL) {
-        if (pos >= buflen) {
+        newline = strchr(buffer, EOF);
-            errno = ERANGE;
+        if (newline == NULL) {
-            return NULL;
+            newline = strchr(buffer, 0);
-        }
+            if (newline == NULL) {
-        // If we have found a newline or the EOF, parse the entry.
+                return 0;
-        if ((c == '\n') || (ret == EOF)) {
+            }
-            // Close the buffer.
+        }
-            buf[pos] = 0;
+    }
-            // Check the entry.
+    long newline_len = (int)(newline - buffer);
-            if (name) {
+    if (newline_len <= 0) {
-                if (strncmp(buf, name, strlen(name)) == 0)
+        return 0;
-                    return buf;
+    }
-            } else {
+    buffer[newline_len] = 0;
-                int uid_start = -1, col_count = 0;
+    long rollback       = newline_len - num_read + 1;
-                for (int i = 0; i < pos; ++i) {
+    if (rollback > 1) {
-                    if (buf[i] == ':') {
+        return 0;
-                        if (++col_count == 2) {
+    }
-                            uid_start = i + 1;
+    lseek(fd, rollback, SEEK_CUR);
-                            break;
+    return newline_len;
-                        }
+}
-                    }
+
-                }
+static inline char *__search_entry(int fd, char *buffer, int buflen, const char *name, uid_t uid)
-                if ((uid_start != -1) && (uid_start < pos)) {
+{
-                    // Parse the uid.
+    while (__readline(fd, buffer, buflen)) {
-                    int found_uid = atoi(&buf[uid_start]);
+        if (name != NULL) {
-                    // Check the uid.
+            char *name_end = strchr(buffer, ':');
-                    if (found_uid == uid)
+            if (name_end) {
-                        return buf;
+                *name_end = '\0';
-                }
+                if (strncmp(buffer, name, strlen(name)) == 0) {
+                    *name_end = ':';
+                    return buffer;
+                }
+            }
+        } else {
+            // Name
+            char *ptr = strchr(buffer, ':');
+            if (ptr == NULL)
+                continue;
+            // Password
+            ++ptr;
+            char *uid_start = strchr(ptr, ':');
+            if (uid_start == NULL)
+                continue;
+            ++uid_start;
+            ptr = strchr(uid_start, ':');
+            if (ptr == NULL)
+                continue;
+            *ptr = '\0';
+            // Parse the uid.
+            int found_uid = atoi(uid_start);
+            // Check the uid.
+            if (found_uid == uid) {
+                *ptr = ':';
+                return buffer;
             }
-            // Reset the index.
-            pos = 0;
-            // If we have reached the EOF stop.
-            if (ret == EOF)
-                break;
-        } else {
-            buf[pos++] = c;
         }
     }
-    errno = ENOENT;
     return NULL;
 }
 
@@ -119,6 +148,7 @@ int getpwnam_r(const char *name, passwd_t *pwd, char *buf, size_t buflen, passwd
         return 0;
     int fd = open("/etc/passwd", O_RDONLY, 0);
     if (fd == -1) {
+        pr_debug("Cannot open `/etc/passwd`\n");
         errno   = ENOENT;
         *result = NULL;
         return 0;
@@ -132,6 +162,7 @@ int getpwnam_r(const char *name, passwd_t *pwd, char *buf, size_t buflen, passwd
         // Return success.
         return 1;
     }
+    errno = ENOENT;
     // Close the file.
     close(fd);
     // Return fail.
@@ -142,6 +173,7 @@ int getpwuid_r(uid_t uid, passwd_t *pwd, char *buf, size_t buflen, passwd_t **re
 {
     int fd = open("/etc/passwd", O_RDONLY, 0);
     if (fd == -1) {
+        pr_debug("Cannot open `/etc/passwd`\n");
         errno   = ENOENT;
         *result = NULL;
         return 0;

libc/src/sched.c

@@ -1,6 +1,7 @@
-//
+/// @file sched.c
-// Created by enryf on 24/09/2020.
+/// @brief Function for managing scheduler.
-//
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
 
 #include "system/syscall_types.h"
 #include "sys/errno.h"

libc/src/setenv.c

@@ -1,5 +1,7 @@
 /// @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.
+/// See LICENSE.md for details.
 
 #include <assert.h>
 #include "sys/errno.h"

libc/src/stdio.c

@@ -1,6 +1,7 @@
-/// @file   stdio.c
+/// @file stdio.c
-/// @brief  Standard I/0 functions.
+/// @brief Standard I/0 functions.
-/// @date   Apr 2019
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
 
 #include <sys/errno.h>
 #include "stdio.h"

libc/src/stdlib.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file stdlib.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "system/syscall_types.h"

libc/src/strerror.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file strerror.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "strerror.h"
@@ -15,6 +14,11 @@ char *strerror(int errnum)
     case 0:
         strcpy(error, "Success");
         break;
+#ifdef EPERM
+    case EPERM:
+        strcpy(error, "Operation not permitted");
+        break;
+#endif
 #ifdef ENOENT
     case ENOENT:
         strcpy(error, "No such file or directory");

libc/src/string.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file string.c
 /// @brief String routines.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include <fcntl.h>

libc/src/sys/errno.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file errno.c
 /// @brief Stores the error number.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/errno.h"

libc/src/sys/ioctl.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file ioctl.c
 /// @brief Input/Output ConTroL (IOCTL) functions implementation.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/ioctl.h"

libc/src/sys/unistd.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file unistd.c
 /// @brief Functions used to manage files.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/unistd.h"

libc/src/sys/utsname.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file utsname.c
 /// @brief Functions used to provide information about the machine & OS.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/utsname.h"

libc/src/termios.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file termios.c
 /// @brief
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "termios.h"
@@ -9,7 +8,7 @@
 #include "sys/errno.h"
 #include "bits/ioctls.h"
 
-int tcgetattr(int fd, termios *termios_p)
+int tcgetattr(int fd, termios_t *termios_p)
 {
     int retval;
     __asm__ volatile("int $0x80"
@@ -23,7 +22,7 @@ int tcgetattr(int fd, termios *termios_p)
     return retval;
 }
 
-int tcsetattr(int fd, int optional_actions, const termios *termios_p)
+int tcsetattr(int fd, int optional_actions, const termios_t *termios_p)
 {
     int retval;
     __asm__ volatile("int $0x80"

libc/src/time.c

@@ -1,7 +1,6 @@
-///                MentOS, The Mentoring Operating system project
 /// @file time.c
 /// @brief Clock functions.
-/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2022 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "time.h"
@@ -19,6 +18,7 @@ static const char *months[] = {
     "July", "August", "September", "October", "November", "December"
 };
 
+/// @brief Time function.
 _syscall1(time_t, time, time_t *, t)
 
 time_t difftime(time_t time1, time_t time2)
@@ -378,6 +378,7 @@ size_t strftime(char *str, size_t maxsize, const char *format, const tm_t *timep
     return ret;
 }
 
+/// @brief nanosleep function.
 _syscall2(int, nanosleep, const timespec *, req, timespec *, rem)
 
 unsigned int sleep(unsigned int seconds)