Merge branch 'develop' into feature/remove_nasm

do not append to gdb.run

.github/workflows/macos.yml

@@ -1,36 +0,0 @@
-name: MacOS
-on:
-    push:
-        branches-ignore:
-            - "releases/**"
-        paths-ignore:
-            - "**.md"
-            - ".gitignore"
-            - "**/ubuntu.yml"
-            - "**/windows.yml"
-    pull_request:
-        paths-ignore:
-            - "**.md"
-            - ".gitignore"
-            - "**/ubuntu.yml"
-            - "**/windows.yml"
-jobs:
-    build:
-        name: Build
-        runs-on: macos-latest
-        # Set environment variables
-        #env:
-            # We globally set CC and CXX.
-        #    CC: x86_64-elf-gcc
-        #    CXX: x86_64-elf-g++
-        steps:
-            - name: Clone repository
-              uses: actions/checkout@v3
-            - name: Install dependencies
-              run: |
-                brew install git cmake nasm
-            # x86_64-elf-binutils x86_64-elf-gcc 
-            - name: Build
-              run: |
-                  cmake -B build
-                  cmake --build build --parallel 2

.github/workflows/windows.yml

@@ -1,36 +0,0 @@
-name: Windows
-on:
-    push:
-        branches-ignore:
-            - "releases/**"
-        paths-ignore:
-            - "**.md"
-            - ".gitignore"
-            - "**/macos.yml"
-            - "**/ubuntu.yml"
-    pull_request:
-        paths-ignore:
-            - "**.md"
-            - ".gitignore"
-            - "**/macos.yml"
-            - "**/ubuntu.yml"
-jobs:
-    test:
-        name: Build
-        runs-on: windows-latest
-        steps:
-            - name: Clone repo
-              uses: actions/checkout@v3
-            - name: Install dependencies
-              run: |
-                  choco install nasm
-                  echo "C:\Program Files\NASM" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-            - name: Set up MinGW
-              uses: egor-tensin/setup-mingw@v2
-              with:
-                  version: latest
-                  platform: x32
-            - name: Build
-              run: |
-                  cmake -B build
-                  cmake --build build --parallel 2

CMakeLists.txt

@@ -61,6 +61,54 @@ else()
     set(CMAKE_LINKER ld)
 endif()
 
+# Enable the assembly language.
+enable_language(ASM)
+# Find the NASM compiler.
+find_program(ASM_COMPILER NAMES nasm HINTS /usr/bin/ /usr/local/bin/)
+# Mark the variable ASM_COMPILER as advanced.
+mark_as_advanced(ASM_COMPILER)
+# Check that we have found the compiler.
+if(NOT ASM_COMPILER)
+    message(FATAL_ERROR "ASM compiler not found!")
+endif(NOT ASM_COMPILER)
+
+# Set the assembly compiler flags.
+set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -m32")
+# Warning flags.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
+# Disable some specific warnings.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-braces")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-command-line-argument")
+# Set the compiler options.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ffreestanding")
+if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
+endif()
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
+endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
+
 # =============================================================================
 # COMPILATION
 # =============================================================================
@@ -135,8 +183,8 @@ set(EMULATOR_FLAGS ${EMULATOR_FLAGS} -drive file=${CMAKE_BINARY_DIR}/rootfs.img,
 add_custom_target(
     qemu
     COMMAND test -e ${CMAKE_BINARY_DIR}/rootfs.img || ${CMAKE_COMMAND} -E cmake_echo_color --red "No filesystem file detected, you need to run: make filesystem"
-    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -kernel ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin
+    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -kernel ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin
-    DEPENDS kernel-bootloader.bin
+    DEPENDS kernel_bootloader.bin
 )
 
 # =============================================================================
@@ -147,17 +195,17 @@ add_custom_target(
 # executables.
 add_custom_target(
     gdbinit
-    BYPRODUCTS ${CMAKE_BINARY_DIR}/.gdbinit ${CMAKE_BINARY_DIR}/gdb.run
+    BYPRODUCTS ${CMAKE_BINARY_DIR}/.gdbinit
-    # Create the generic gdb configuration.
+    COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/mentos/kernel.bin > ${CMAKE_BINARY_DIR}/.gdbinit
-    COMMAND echo "add-symbol-file ${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 echo "add-symbol-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}/programs/tests/test_* >> ${CMAKE_BINARY_DIR}/.gdbinit
-    COMMAND ls -1 ${CMAKE_BINARY_DIR}/programs/tests/test_* | sed 's/^/add-symbol-file /' >> ${CMAKE_BINARY_DIR}/.gdbinit
+    COMMAND bash ${CMAKE_SOURCE_DIR}/scripts/get_text_address.sh ${CMAKE_BINARY_DIR}/programs/prog_* >> ${CMAKE_BINARY_DIR}/.gdbinit
-    COMMAND ls -1 ${CMAKE_BINARY_DIR}/programs/prog_* | sed 's/^/add-symbol-file /' >> ${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
     # Create the GDB connection file.
-    COMMAND echo "target remote localhost:1234" >> ${CMAKE_BINARY_DIR}/gdb.run
+    COMMAND echo "target remote localhost:1234" > ${CMAKE_BINARY_DIR}/gdb.run
-    DEPENDS kernel-bootloader.bin
+    DEPENDS ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin
+    DEPENDS ${CMAKE_BINARY_DIR}/mentos/kernel.bin
     DEPENDS all_programs
     DEPENDS all_tests
     DEPENDS libc
@@ -169,17 +217,15 @@ add_custom_target(
 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 ""
+    COMMAND echo "\n\n"
-    COMMAND echo "Now, QEMU has loaded the kernel, and it is waiting that you"
+    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"
+    COMMAND echo "remotely connect to it. To start debugging, open a new shell\n"
-    COMMAND echo "in THIS same folder, and just type:"
+    COMMAND echo "in THIS same folder, and just type :\n"
-    COMMAND echo "    gdb --quiet --command=gdb.run"
+    COMMAND printf "    cgdb -q -iex %q" "add-auto-load-safe-path ."
-    COMMAND echo "or if you want to use cgdb, type:"
+    COMMAND echo "\n\n"
-    COMMAND echo "    cgdb --quiet --command=gdb.run"
+    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -s -S -kernel ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin
-    COMMAND echo ""
+    DEPENDS kernel_bootloader.bin
-    COMMAND ${EMULATOR} ${EMULATOR_FLAGS} -s -S -kernel ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin
+    DEPENDS .gdbinit
-    DEPENDS kernel-bootloader.bin
-    DEPENDS gdbinit
 )
 
 # =============================================================================
@@ -190,9 +236,9 @@ add_custom_target(
 add_custom_target(
   cdrom.iso
   COMMAND cp -rf ${CMAKE_SOURCE_DIR}/iso .
-  COMMAND cp ${CMAKE_BINARY_DIR}/mentos/kernel-bootloader.bin ${CMAKE_BINARY_DIR}/iso/boot
+  COMMAND cp ${CMAKE_BINARY_DIR}/mentos/kernel_bootloader.bin ${CMAKE_BINARY_DIR}/iso/boot
   COMMAND grub-mkrescue -o ${CMAKE_BINARY_DIR}/cdrom.iso ${CMAKE_BINARY_DIR}/iso
-  DEPENDS kernel-bootloader.bin
+  DEPENDS kernel_bootloader.bin
 )
 
 # This third target runs the emualtor, but this time, the kernel binary file is

README.md

@@ -5,24 +5,29 @@
 [![forthebadge](https://forthebadge.com/images/badges/for-you.svg)](https://forthebadge.com)
 
 [![Ubuntu](https://github.com/mentos-team/MentOS/actions/workflows/ubuntu.yml/badge.svg)](https://github.com/mentos-team/MentOS/actions/workflows/ubuntu.yml)
-[![MacOS](https://github.com/mentos-team/MentOS/actions/workflows/macos.yml/badge.svg)](https://github.com/mentos-team/MentOS/actions/workflows/macos.yml)
 
 ## Table of Contents
 
- 1. [What is MentOS](#1-what-is-mentos)
+- [MentOS (Mentoring Operating System)](#mentos-mentoring-operating-system)
- 2. [Implemented features](#2-implemented-features)
+  - [Table of Contents](#table-of-contents)
- 3. [Prerequisites](#3-prerequisites)
+  - [What is MentOS](#what-is-mentos)
- 4. [Compiling MentOS](#4-compiling-mentos)
+  - [Implemented features](#implemented-features)
- 5. [Generating the EXT2 filesystem](#5-generating-the-ext2-filesystem)
+  - [Prerequisites](#prerequisites)
- 6. [Running MentOS](#6-running-mentos)
+    - [Installing the prerequisites](#installing-the-prerequisites)
- 7. [Running MentOS from GRUB](#7-running-mentos-from-grub)
+  - [Compiling MentOS](#compiling-mentos)
- 8. [Running and adding new programs to MentOS](#8-running-and-adding-new-programs-to-mentos)
+  - [Generating the EXT2 filesystem](#generating-the-ext2-filesystem)
- 9. [Kernel logging](#9-kernel-logging)
+  - [Running MentOS](#running-mentos)
- 10. [Change the scheduling algorithm](#10-change-the-scheduling-algorithm)
+  - [Running MentOS from GRUB](#running-mentos-from-grub)
- 11. [Debugging the kernel](#11-debugging-the-kernel)
+  - [Running and adding new programs to MentOS](#running-and-adding-new-programs-to-mentos)
- 12. [Contributors](#12-contributors)
+    - [Create a new program](#create-a-new-program)
+    - [Add the new program to the list of compiled sources](#add-the-new-program-to-the-list-of-compiled-sources)
+    - [Running a program or a test](#running-a-program-or-a-test)
+  - [Kernel logging](#kernel-logging)
+  - [Change the scheduling algorithm](#change-the-scheduling-algorithm)
+  - [Debugging the kernel](#debugging-the-kernel)
+  - [Contributors](#contributors)
 
-## 1. What is MentOS
+## What is MentOS
 
 MentOS (Mentoring Operating System) is an open source educational operating
 system. The goal of MentOS is to provide a project environment that is realistic
@@ -46,7 +51,8 @@ Gualandri.
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 2. Implemented features
+## Implemented features
+
 Follows the list of implemented features:
 
 **Processes and Events**
@@ -91,22 +97,18 @@ I will try to keep it updated...
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 3. Prerequisites
+## Prerequisites
 
 MentOS is compatible with the main **unix-based** operating systems. It has been
-tested with *Ubuntu*, *WSL1*, *WSL2*, and  *MacOS*.
+tested with *Ubuntu*, and under Windows with *WSL1* and *WSL2*.
 
-### 3.1. Generic Prerequisites
+For **compiling** the system we need:
 
-#### 3.1.1. Compile
+ - git
-
-For compiling the system:
-
- - nasm
  - gcc
+ - nasm
  - make
  - cmake
- - git
  - ccmake (suggested)
  - e2fsprogs (should be already installed)
 
@@ -115,43 +117,29 @@ Under **MacOS**, for compiling, you have additional dependencies:
  - i386-elf-binutils
  - i386-elf-gcc
 
-#### 3.1.2. Execute
+For **executing** the operating system we need:
-
-To execute the operating system, you need to install:
 
  - qemu-system-i386 (or qemu-system-x86)
 
-#### 3.1.3. Debug
+For **debugging** we suggest using:
-
-For debugging we suggest using:
 
  - gdb or cgdb
 
-### 3.2. installation Prerequisites
+### Installing the prerequisites
 
 Under **Ubuntu**, you can type the following commands:
 
 ```bash
 sudo apt-get update && sudo apt-get upgrade -y
-sudo apt-get install -y build-essential git cmake qemu-system-x86 nasm e2fsprogs
+sudo apt-get install -y git build-essential nasm make cmake cmake-curses-gui e2fsprogs
+sudo apt-get install -y qemu-system-x86
 sudo apt-get install -y gdb cgdb
 ```
 Note: Older versions might have `qemu-system-i386` instead of `qemu-system-x86`.
 
-Under **MacOS** you also need to install the i386-elf cross-compiler. The
-simplest installation method is through Homebrew package manager.
-Install [Homebrew](https://brew.sh/index_it) if you don't already have it, and
-then type the following commands:
-
-```bash
-brew update && brew upgrade
-brew install i386-elf-binutils i386-elf-gcc git cmake qemu nasm e2fsprogs
-brew install gdb cgdb #<- for debug only
-```
-
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 4. Compiling MentOS
+## Compiling MentOS
 
 Compile MentOS with:
 
@@ -165,7 +153,7 @@ make
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 5. Generating the EXT2 filesystem
+## Generating the EXT2 filesystem
 
 Generate the EXT2 filesystem with:
 
@@ -176,7 +164,7 @@ you just need to generate the filesystem once. If you change a `program` you nee
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 6. Running MentOS
+## Running MentOS
 
 Boot MentOS with qemu:
 
@@ -188,7 +176,7 @@ To login, use one of the usernames listed in `files/etc/passwd`.
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 7. Running MentOS from GRUB
+## Running MentOS from GRUB
 
 For booting MentOS from GRUB in QEMU we need the following tools:
 
@@ -211,11 +199,11 @@ make qemu-grub
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 8. Running and adding new programs to MentOS
+## Running and adding new programs to MentOS
 
 This section explains how to add a new program to MentOS, and also how to run programs in mentos. It also explains how to add new tests, which are located in the `programs/tests` folder.
 
-### 8.1. Create a new program
+### Create a new program
 
 Head to the `programs` (or the `programs/tests`) folder. Create and open a new program, for instance a file called `hello_world.c`, with your preferred editor, and add this content to the file:
 ```C
@@ -228,7 +216,7 @@ int main(int argc, char *argv[])
 }
 ```
 
-### 8.2. Add the new program to the list of compiled sources
+### Add the new program to the list of compiled sources
 Now we can add the program to the list of files which are compiled and placed inside MentOS filesystem.
 The following procedure is the same for both `programs` and `programs/tests`, what changes is which `CMakeLists.txt` file we modify.
 
@@ -253,7 +241,7 @@ set(TESTS
 
 That's it, the `hello_world.c` file will be compiled and will appear inside the `/bin` or `/bin/tests` folder of MentOS.
 
-### 8.3. Running a program or a test
+### Running a program or a test
 Once you login into MentOS, if you placed your source code in `programs`, you can execute the program by simply typing:
 ```bash
 hello_world
@@ -268,7 +256,7 @@ However, the `/bin/tests` folder is not listed in `PATH`, so, if you want to exe
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 9. Kernel logging
+## 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:
@@ -322,7 +310,7 @@ This example sets the `__DEBUG_LEVEL__`, so that all the messages from `INFO` an
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 10. Change the scheduling algorithm
+## Change the scheduling algorithm
 
 MentOS supports scheduling algorithms for aperiodic:
 
@@ -390,7 +378,7 @@ make qemu
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 11. Debugging the kernel
+## Debugging the kernel
 
 If you want to use GDB to debug MentOS, first you need to compile everything:
 
@@ -450,7 +438,7 @@ to connect to the running process.
 
 *[Back to the Table of Contents](#table-of-contents)*
 
-## 12. Contributors
+## Contributors
 
 Project Manager:
 
@@ -472,5 +460,9 @@ Developers:
     - Soft IRQs
     - Timer
     - Signals
+* And many other valuable contributors
+  * [rouseabout](https://github.com/rouseabout)
+  * [seekbytes](https://github.com/seekbytes)
+  * [fischerling](https://github.com/fischerling)
 
 *[Back to the Table of Contents](#table-of-contents)*

libc/CMakeLists.txt

@@ -1,146 +1,70 @@
-# =============================================================================
+# Add the libc library.
-# Author: Enrico Fraccaroli
+add_library(libc
-# =============================================================================
+    ${PROJECT_SOURCE_DIR}/libc/src/stdio.c
-# Set the minimum required version of cmake.
+    ${PROJECT_SOURCE_DIR}/libc/src/ctype.c
-cmake_minimum_required(VERSION 3.1...3.22)
+    ${PROJECT_SOURCE_DIR}/libc/src/string.c
-# Initialize the project.
+    ${PROJECT_SOURCE_DIR}/libc/src/stdlib.c
-project(libc C ASM)
+    ${PROJECT_SOURCE_DIR}/libc/src/math.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/fcvt.c
-# =============================================================================
+    ${PROJECT_SOURCE_DIR}/libc/src/time.c
-# ASSEMBLY
+    ${PROJECT_SOURCE_DIR}/libc/src/strerror.c
-# =============================================================================
+    ${PROJECT_SOURCE_DIR}/libc/src/termios.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/libgen.c
-# Enable the assembly language.
+    ${PROJECT_SOURCE_DIR}/libc/src/vsprintf.c
-enable_language(ASM)
+    ${PROJECT_SOURCE_DIR}/libc/src/vscanf.c
-# Find the NASM compiler.
+    ${PROJECT_SOURCE_DIR}/libc/src/pwd.c
-find_program(ASM_COMPILER NAMES nasm HINTS /usr/bin/ /usr/local/bin/)
+    ${PROJECT_SOURCE_DIR}/libc/src/grp.c
-# Mark the variable ASM_COMPILER as advanced.
+    ${PROJECT_SOURCE_DIR}/libc/src/sched.c
-mark_as_advanced(ASM_COMPILER)
+    ${PROJECT_SOURCE_DIR}/libc/src/readline.c
-# Check that we have found the compiler.
+    ${PROJECT_SOURCE_DIR}/libc/src/setenv.c
-if(NOT ASM_COMPILER)
+    ${PROJECT_SOURCE_DIR}/libc/src/assert.c
-    message(FATAL_ERROR "ASM compiler not found!")
+    ${PROJECT_SOURCE_DIR}/libc/src/abort.c
-endif(NOT ASM_COMPILER)
+    ${PROJECT_SOURCE_DIR}/libc/src/io/mm_io.c
-# Set the asm compiler.
+    ${PROJECT_SOURCE_DIR}/libc/src/io/debug.c
-set(CMAKE_ASM_COMPILER ${ASM_COMPILER})
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/ipc.c
-# Set the assembly compiler flags.
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/unistd.c
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/errno.c
-    set(CMAKE_ASM_COMPILE_OBJECT "<CMAKE_ASM_COMPILER> -f elf -g -O0 -F dwarf -o <OBJECT> <SOURCE>")
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/utsname.c
-else()
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/mman.c
-    set(CMAKE_ASM_COMPILE_OBJECT "<CMAKE_ASM_COMPILER> -f elf -g -O3 -o <OBJECT> <SOURCE>")
+    ${PROJECT_SOURCE_DIR}/libc/src/sys/ioctl.c
-endif()
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/creat.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getppid.c
-# =============================================================================
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getpid.c
-# C WARNINGs
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/exit.c
-# =============================================================================
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setsid.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getsid.c
-# Warning flags.
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setpgid.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getpgid.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setgid.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getgid.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/setuid.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getuid.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/fork.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/read.c
-# Disable some specific warnings.
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/write.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/exec.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/nice.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/open.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-braces")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/reboot.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/waitpid.c
-# Set the compiler options.
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/chdir.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getcwd.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/close.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/stat.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/rmdir.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/mkdir.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/unlink.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/getdents.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/lseek.c
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/kill.c
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/signal.c
-endif()
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/interval.c
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/symlink.c
-
+    ${PROJECT_SOURCE_DIR}/libc/src/unistd/readlink.c
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    ${PROJECT_SOURCE_DIR}/libc/src/libc_start.c
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
+    ${PROJECT_SOURCE_DIR}/libc/src/crt0.s
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
-elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
-endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-
-# =============================================================================
-# Add the library.
-add_library(
-    ${PROJECT_NAME}
-
-    ${PROJECT_SOURCE_DIR}/src/stdio.c
-    ${PROJECT_SOURCE_DIR}/src/ctype.c
-    ${PROJECT_SOURCE_DIR}/src/string.c
-    ${PROJECT_SOURCE_DIR}/src/stdlib.c
-    ${PROJECT_SOURCE_DIR}/src/math.c
-    ${PROJECT_SOURCE_DIR}/src/fcvt.c
-    ${PROJECT_SOURCE_DIR}/src/time.c
-    ${PROJECT_SOURCE_DIR}/src/strerror.c
-    ${PROJECT_SOURCE_DIR}/src/termios.c
-    ${PROJECT_SOURCE_DIR}/src/libgen.c
-    ${PROJECT_SOURCE_DIR}/src/vsprintf.c
-    ${PROJECT_SOURCE_DIR}/src/vscanf.c
-    ${PROJECT_SOURCE_DIR}/src/pwd.c
-    ${PROJECT_SOURCE_DIR}/src/grp.c
-    ${PROJECT_SOURCE_DIR}/src/sched.c
-    ${PROJECT_SOURCE_DIR}/src/readline.c
-    ${PROJECT_SOURCE_DIR}/src/setenv.c
-    ${PROJECT_SOURCE_DIR}/src/assert.c
-    ${PROJECT_SOURCE_DIR}/src/abort.c
-    ${PROJECT_SOURCE_DIR}/src/io/mm_io.c
-    ${PROJECT_SOURCE_DIR}/src/io/debug.c
-    ${PROJECT_SOURCE_DIR}/src/sys/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/mman.c
-    ${PROJECT_SOURCE_DIR}/src/sys/ioctl.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/creat.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getppid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getpid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/exit.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setsid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getsid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setpgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getpgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getgid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/setuid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getuid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/fork.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/read.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/write.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/exec.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/nice.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/open.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/reboot.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/waitpid.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/chdir.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getcwd.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/close.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/stat.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/rmdir.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/mkdir.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/unlink.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/getdents.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/lseek.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/kill.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/signal.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/interval.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/symlink.c
-    ${PROJECT_SOURCE_DIR}/src/unistd/readlink.c
-    ${PROJECT_SOURCE_DIR}/src/libc_start.c
-    ${PROJECT_SOURCE_DIR}/src/crt0.S
 )
-
 # Add the includes.
-target_include_directories(${PROJECT_NAME} PUBLIC inc)
+target_include_directories(libc PRIVATE ${PROJECT_SOURCE_DIR}/libc/inc)
-
 # Remove the 'lib' prefix.
-set_target_properties(${PROJECT_NAME} PROPERTIES PREFIX "")
+set_target_properties(libc PROPERTIES PREFIX "")

libc/src/crt0.s

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

libc/src/unistd/waitpid.c

@@ -1,6 +1,6 @@
 /// @file waitpid.c
 /// @brief
-/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// @copyright (c) 2014-2024 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
 #include "sys/unistd.h"
@@ -18,19 +18,17 @@ pid_t waitpid(pid_t pid, int *status, int options)
     int __status = 0;
     do {
         __inline_syscall3(__res, waitpid, pid, &__status, options);
-        if (__res < 0) {
+        if (__res != 0) {
             break;
-}
+        }
-        if (__status == EXIT_ZOMBIE) {
-            break;
-}
         if (options && WNOHANG) {
             break;
-}
+        }
     } while (1);
+
     if (status) {
         *status = __status;
-}
+    }
     __syscall_return(pid_t, __res);
 }
 

mentos/CMakeLists.txt

@@ -1,15 +1,9 @@
-# =============================================================================
-# Set the minimum required version of cmake.
-cmake_minimum_required(VERSION 3.1...3.22)
-# Initialize the project.
-project(kernel C ASM)
-
 # =============================================================================
 # Set the main file names.
 set(KERNEL_NAME       kernel)
 set(BOOTLOADER_NAME   kernel_bootloader)
 set(BUDDY_SYSTEM_NAME kernel_memory)
-set(BUDDY_SYSTEM_FILE ${PROJECT_SOURCE_DIR}/src/mem/libbuddysystem.a)
+set(BUDDY_SYSTEM_FILE ${CMAKE_CURRENT_SOURCE_DIR}/src/mem/libbuddysystem.a)
 
 # =============================================================================
 # OPTIONS
@@ -24,166 +18,103 @@ option(ENABLE_ALLOC_TRACE "Enables memory allocation tracing." OFF)
 # Enables scheduling feedback on terminal.
 option(ENABLE_SCHEDULER_FEEDBACK "Enables scheduling feedback on terminal." OFF)
 
-# =============================================================================
-# ASSEMBLY
-# =============================================================================
-
-# Enable the assembly language.
-enable_language(ASM)
-# Find the NASM compiler.
-find_program(ASM_COMPILER NAMES nasm HINTS /usr/bin/ /usr/local/bin/)
-# Mark the variable ASM_COMPILER as advanced.
-mark_as_advanced(ASM_COMPILER)
-# Check that we have found the compiler.
-if(NOT ASM_COMPILER)
-    message(FATAL_ERROR "ASM compiler not found!")
-endif(NOT ASM_COMPILER)
-# Set the asm compiler.
-set(CMAKE_ASM_COMPILER ${ASM_COMPILER})
-# Set the assembly compiler flags.
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_ASM_COMPILE_OBJECT "<CMAKE_ASM_COMPILER> -f elf -g -O0 -F dwarf -o <OBJECT> <SOURCE>")
-else()
-    set(CMAKE_ASM_COMPILE_OBJECT "<CMAKE_ASM_COMPILER> -f elf -g -O3 -o <OBJECT> <SOURCE>")
-endif()
-
-# =============================================================================
-# C WARNINGs
-# =============================================================================
-
-# Warning flags.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
-
-# Disable some specific warnings.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-braces")
-
-# Set the compiler options.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
-endif()
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
-elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
-endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-
 # =============================================================================
 # SOURCES
 # =============================================================================
 
 # Define the list of files.
 set(KERNEL_SOURCES
-    ${PROJECT_SOURCE_DIR}/src/kernel.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/kernel.c
-    ${PROJECT_SOURCE_DIR}/src/multiboot.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/multiboot.c
-    ${PROJECT_SOURCE_DIR}/src/devices/pci.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/devices/pci.c
-    ${PROJECT_SOURCE_DIR}/src/devices/fpu.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/devices/fpu.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/ata.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/ata.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/rtc.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/rtc.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/fdc.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/fdc.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/mouse.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/mouse.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/ps2.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/ps2.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/keyboard/keyboard.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/keyboard/keyboard.c
-    ${PROJECT_SOURCE_DIR}/src/drivers/keyboard/keymap.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/drivers/keyboard/keymap.c
-    ${PROJECT_SOURCE_DIR}/src/fs/vfs.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/vfs.c
-    ${PROJECT_SOURCE_DIR}/src/fs/read_write.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/read_write.c
-    ${PROJECT_SOURCE_DIR}/src/fs/open.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/open.c
-    ${PROJECT_SOURCE_DIR}/src/fs/stat.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/stat.c
-    ${PROJECT_SOURCE_DIR}/src/fs/readdir.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/readdir.c
-    ${PROJECT_SOURCE_DIR}/src/fs/procfs.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/procfs.c
-    ${PROJECT_SOURCE_DIR}/src/fs/ioctl.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/ioctl.c
-    ${PROJECT_SOURCE_DIR}/src/fs/namei.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/namei.c
-    ${PROJECT_SOURCE_DIR}/src/fs/ext2.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/fs/ext2.c
-    ${PROJECT_SOURCE_DIR}/src/hardware/timer.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/hardware/timer.c
-    ${PROJECT_SOURCE_DIR}/src/hardware/cpuid.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/hardware/cpuid.c
-    ${PROJECT_SOURCE_DIR}/src/hardware/pic8259.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/hardware/pic8259.c
-    ${PROJECT_SOURCE_DIR}/src/io/debug.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/debug.c
-    ${PROJECT_SOURCE_DIR}/src/io/mm_io.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/mm_io.c
-    ${PROJECT_SOURCE_DIR}/src/io/video.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/video.c
-    ${PROJECT_SOURCE_DIR}/src/io/stdio.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/stdio.c
-    ${PROJECT_SOURCE_DIR}/src/io/proc_video.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_video.c
-    ${PROJECT_SOURCE_DIR}/src/io/proc_running.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_running.c
-    ${PROJECT_SOURCE_DIR}/src/io/proc_feedback.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_feedback.c
-    ${PROJECT_SOURCE_DIR}/src/io/proc_system.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_system.c
-    ${PROJECT_SOURCE_DIR}/src/io/proc_ipc.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/proc_ipc.c
-    ${PROJECT_SOURCE_DIR}/src/io/vga/vga.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/io/vga/vga.c
-    ${PROJECT_SOURCE_DIR}/src/ipc/ipc.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/ipc/ipc.c
-    ${PROJECT_SOURCE_DIR}/src/ipc/msg.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/ipc/msg.c
-    ${PROJECT_SOURCE_DIR}/src/ipc/sem.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/ipc/sem.c
-    ${PROJECT_SOURCE_DIR}/src/ipc/shm.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/ipc/shm.c
-    ${PROJECT_SOURCE_DIR}/src/kernel/sys.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/kernel/sys.c
-    ${PROJECT_SOURCE_DIR}/src/klib/assert.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/assert.c
-    ${PROJECT_SOURCE_DIR}/src/klib/ctype.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/ctype.c
-    ${PROJECT_SOURCE_DIR}/src/klib/mutex.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/mutex.c
-    ${PROJECT_SOURCE_DIR}/src/klib/string.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/string.c
-    ${PROJECT_SOURCE_DIR}/src/klib/vsprintf.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/vsprintf.c
-    ${PROJECT_SOURCE_DIR}/src/klib/vscanf.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/vscanf.c
-    ${PROJECT_SOURCE_DIR}/src/klib/time.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/time.c
-    ${PROJECT_SOURCE_DIR}/src/klib/libgen.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/libgen.c
-    ${PROJECT_SOURCE_DIR}/src/klib/strerror.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/strerror.c
-    ${PROJECT_SOURCE_DIR}/src/klib/math.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/math.c
-    ${PROJECT_SOURCE_DIR}/src/klib/fcvt.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/fcvt.c
-    ${PROJECT_SOURCE_DIR}/src/klib/spinlock.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/spinlock.c
-    ${PROJECT_SOURCE_DIR}/src/klib/stdlib.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/stdlib.c
-    ${PROJECT_SOURCE_DIR}/src/klib/rbtree.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/rbtree.c
-    ${PROJECT_SOURCE_DIR}/src/klib/ndtree.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/ndtree.c
-    ${PROJECT_SOURCE_DIR}/src/klib/hashmap.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/hashmap.c
-    ${PROJECT_SOURCE_DIR}/src/klib/list.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/klib/list.c
-    ${PROJECT_SOURCE_DIR}/src/mem/kheap.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/mem/kheap.c
-    ${PROJECT_SOURCE_DIR}/src/mem/paging.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/mem/paging.c
-    ${PROJECT_SOURCE_DIR}/src/mem/slab.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/mem/slab.c
-    ${PROJECT_SOURCE_DIR}/src/mem/vmem_map.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/mem/vmem_map.c
-    ${PROJECT_SOURCE_DIR}/src/mem/zone_allocator.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/mem/zone_allocator.c
-    ${PROJECT_SOURCE_DIR}/src/elf/elf.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/elf/elf.c
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/gdt.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/gdt.c
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/gdt.S
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/gdt.s
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/interrupt.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/interrupt.c
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/exception.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/exception.c
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/interrupt.S
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/interrupt.s
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/exception.S
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/exception.s
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/idt.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/idt.c
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/idt.S
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/idt.s
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/tss.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/tss.c
-    ${PROJECT_SOURCE_DIR}/src/descriptor_tables/tss.S
+    ${PROJECT_SOURCE_DIR}/mentos/src/descriptor_tables/tss.s
-    ${PROJECT_SOURCE_DIR}/src/process/scheduler_algorithm.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/process/scheduler_algorithm.c
-    ${PROJECT_SOURCE_DIR}/src/process/scheduler_feedback.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/process/scheduler_feedback.c
-    ${PROJECT_SOURCE_DIR}/src/process/scheduler.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/process/scheduler.c
-    ${PROJECT_SOURCE_DIR}/src/process/process.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/process/process.c
-    ${PROJECT_SOURCE_DIR}/src/process/wait.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/process/wait.c
-    ${PROJECT_SOURCE_DIR}/src/process/user.S
+    ${PROJECT_SOURCE_DIR}/mentos/src/process/user.s
-    ${PROJECT_SOURCE_DIR}/src/sys/utsname.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/sys/utsname.c
-    ${PROJECT_SOURCE_DIR}/src/sys/module.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/sys/module.c
-    ${PROJECT_SOURCE_DIR}/src/system/errno.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/system/errno.c
-    ${PROJECT_SOURCE_DIR}/src/system/panic.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/system/panic.c
-    ${PROJECT_SOURCE_DIR}/src/system/printk.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/system/printk.c
-    ${PROJECT_SOURCE_DIR}/src/system/signal.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/system/signal.c
-    ${PROJECT_SOURCE_DIR}/src/system/syscall.c
+    ${PROJECT_SOURCE_DIR}/mentos/src/system/syscall.c
 )
 
 # =============================================================================
 # Add kernel library.
 if(USE_BUDDY_SYSTEM)
     # Add the library with `buddysystem.c`.
-    add_library(${KERNEL_NAME} ${KERNEL_SOURCES} src/mem/buddysystem.c)
+    add_library(${KERNEL_NAME} ${KERNEL_SOURCES} ${CMAKE_CURRENT_SOURCE_DIR}/src/mem/buddysystem.c)
 else(USE_BUDDY_SYSTEM)
     # Add the library without `buddysystem.c`.
     add_library(${KERNEL_NAME} ${KERNEL_SOURCES})
@@ -201,6 +132,17 @@ target_compile_definitions(
     ${KERNEL_NAME} PUBLIC
     __KERNEL__
 )
+# Link the kernel.
+add_custom_target(
+    ${KERNEL_NAME}.bin
+    COMMAND ${CMAKE_LINKER} -melf_i386 -static --oformat elf32-i386 --output ${KERNEL_NAME}.bin --script ${CMAKE_CURRENT_SOURCE_DIR}/kernel.lds -Map ${KERNEL_NAME}.map -u kmain
+            $<TARGET_FILE_NAME:${KERNEL_NAME}> ${BUDDY_SYSTEM_FILE}
+    COMMAND objcopy -I binary -O elf32-i386 -B i386 ${KERNEL_NAME}.bin ${KERNEL_NAME}.bin.o
+    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/kernel.lds
+    DEPENDS ${KERNEL_NAME}
+    BYPRODUCTS ${KERNEL_NAME}.bin ${KERNEL_NAME}.bin.o
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+)
 
 # =============================================================================
 # Enables cache tracing.
@@ -278,8 +220,8 @@ endif()
 # Add bootloader library.
 add_library(
     ${BOOTLOADER_NAME}
-    src/boot.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/boot.c
-    src/boot.S
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/boot.s
 )
 # Add the includes.
 target_include_directories(
@@ -292,16 +234,21 @@ target_compile_definitions(
     ${BOOTLOADER_NAME} PUBLIC
     __KERNEL__
 )
-
+add_dependencies(
-# =============================================================================
+    ${BOOTLOADER_NAME}
-# Build the kernel.
+    ${KERNEL_NAME}
-add_custom_target(
+)
-    kernel-bootloader.bin ALL
+target_link_libraries(
-    COMMAND ${CMAKE_LINKER} -melf_i386 -static --oformat elf32-i386 --output kernel.bin --script ${CMAKE_CURRENT_SOURCE_DIR}/kernel.lds -Map kernel.map -u kmain
+    ${BOOTLOADER_NAME} PUBLIC
-            $<TARGET_FILE_NAME:${KERNEL_NAME}> ${BUDDY_SYSTEM_FILE}
+    ${KERNEL_NAME}
-    COMMAND objcopy -I binary -O elf32-i386 -B i386 kernel.bin kernel.bin.o
+)
-    COMMAND ${CMAKE_LINKER} -melf_i386 -static --oformat elf32-i386 --output kernel-bootloader.bin --script ${CMAKE_CURRENT_SOURCE_DIR}/boot.lds -Map kernel-bootloader.map
+# Link the bootloader.
-            kernel.bin.o $<TARGET_FILE_NAME:${BOOTLOADER_NAME}>
+add_custom_target(
-    DEPENDS ${KERNEL_NAME}
+    ${BOOTLOADER_NAME}.bin
-    DEPENDS ${BOOTLOADER_NAME}
+    COMMAND ${CMAKE_LINKER} -melf_i386 -static --output ${BOOTLOADER_NAME}.bin --script ${CMAKE_CURRENT_SOURCE_DIR}/boot.lds -Map ${BOOTLOADER_NAME}.map ${KERNEL_NAME}.bin.o $<TARGET_FILE_NAME:${BOOTLOADER_NAME}>
+    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/boot.lds
+    DEPENDS ${BOOTLOADER_NAME}
+    DEPENDS ${KERNEL_NAME}.bin
+    BYPRODUCTS ${BOOTLOADER_NAME}.bin
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
 )

mentos/boot.lds

@@ -9,45 +9,37 @@ MEMORY {
 SECTIONS
 {
 	. = 0x00100000;
-	_bootloader_start = .;
+	
+    _bootloader_start = .;
+
 	.multiboot . : AT(ADDR(.multiboot))
 	{
 		. = ALIGN(4);
-		_multiboot_header_start = .;
 		*(.multiboot_header)
-		_multiboot_header_end   = .;
 	} > BOOTLOADER_MEM
 
     /* Put the .text section. */
     .text . : AT(ADDR(.text))
     {
-        _text_start = .;
         *(.text)
-        _text_end   = .;
     } > BOOTLOADER_MEM
 
     /* Read-only data. */
     .rodata ALIGN(4K) : AT(ADDR(.rodata))
     {
-        _rodata_start = .;
         *(.rodata)
-        _rodata_end   = .;
     } > BOOTLOADER_MEM
 
     /* Read-write data (initialized) */
-    .data   ALIGN(4K) : AT(ADDR(.data))
+    .data ALIGN(4K) : AT(ADDR(.data))
     {
-        _data_start = .;
         *(.data)
-        _data_end   = .;
     } > BOOTLOADER_MEM
 
     /* Read-write data (uninitialized) and stack */
-    .bss    ALIGN(4K) : AT(ADDR(.bss))
+    .bss ALIGN(4K) : AT(ADDR(.bss))
     {
-        _bss_start = .;
         *(.bss*)
-        _bss_end   = .;
     } > BOOTLOADER_MEM
 
     /* Put a symbol end here, it tells us where all the kernel code/data ends,

mentos/inc/process/scheduler.h

@@ -112,3 +112,7 @@ int sys_waitperiod(void);
 /// @param gid ID of the group
 /// @return 1 if the group is orphan, 0 otherwise.
 int is_orphaned_pgrp(pid_t gid);
+
+/// @brief Exit the current process with status
+/// @param status The exit status of the current process
+void do_exit(int status);

mentos/kernel.lds

@@ -15,33 +15,25 @@ SECTIONS
     /* Put the .text section. */
     .text . : AT(ADDR(.text))
     {
-        _text_start = .;
         EXCLUDE_FILE(*boot.*.o) *(.text)
-        _text_end   = .;
     } > KERNEL_LOWMEM
 
     /* Read-only data. */
     .rodata ALIGN(4K) : AT(ADDR(.rodata))
     {
-        _rodata_start = .;
         EXCLUDE_FILE(*boot.*.o) *(.rodata)
-        _rodata_end   = .;
     } > KERNEL_LOWMEM
 
     /* Read-write data (initialized) */
     .data   ALIGN(4K) : AT(ADDR(.data))
     {
-        _data_start = .;
         EXCLUDE_FILE(*boot.*.o) *(.data)
-        _data_end   = .;
     } > KERNEL_LOWMEM
 
     /* Read-write data (uninitialized) and stack */
     .bss    ALIGN(4K) : AT(ADDR(.bss))
     {
-        _bss_start = .;
         *(.bss*)
-        _bss_end   = .;
     } > KERNEL_LOWMEM
 
     /* Put a symbol end here, it tells us where all the kernel code/data ends,

mentos/src/boot.S

@@ -1,103 +0,0 @@
-;                MentOS, The Mentoring Operating system project
-; @file boot.asm
-; @brief Kernel start location, multiboot header
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
-
-bits 32             ; All instructions should be 32-bit.
-extern boot_main    ; The start point of our C code
-
-; The magic field should contain this.
-MULTIBOOT_HEADER_MAGIC     equ 0x1BADB002
-; This should be in %eax.
-MULTIBOOT_BOOTLOADER_MAGIC equ 0x2BADB002
-
-; = Specify what GRUB should PROVIDE =========================================
-; Align the kernel and kernel modules on i386 page (4KB) boundaries.
-MULTIBOOT_PAGE_ALIGN  equ 0x00000001
-; Provide the kernel with memory information.
-MULTIBOOT_MEMORY_INFO equ 0x00000002
-; Must pass video information to OS.
-MULTIBOOT_VIDEO_MODE  equ 0x00000004
-; -----------------------------------------------------------------------------
-
-; This is the flag combination that we prepare for Grub
-; to read at kernel load time.
-MULTIBOOT_HEADER_FLAGS  equ (MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO)
-; Grub reads this value to make sure it loads a kernel
-; and not just garbage.
-MULTIBOOT_CHECKSUM      equ -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
-
-LOAD_MEMORY_ADDRESS equ 0x00000000
-; reserve (1024*1024) for the stack on a doubleword boundary
-KERNEL_STACK_SIZE   equ 0x100000
-
-; -----------------------------------------------------------------------------
-; SECTION (multiboot_header)
-; -----------------------------------------------------------------------------
-section .multiboot_header
-align 4
-; This is the GRUB Multiboot header.
-multiboot_header:
-    ; magic
-    dd MULTIBOOT_HEADER_MAGIC
-    ; flags
-    dd MULTIBOOT_HEADER_FLAGS
-    ; checksum
-    dd MULTIBOOT_CHECKSUM
-
-; -----------------------------------------------------------------------------
-; SECTION (data)
-; -----------------------------------------------------------------------------
-; section .data nobits
-; align 4096
-
-; -----------------------------------------------------------------------------
-; SECTION (text)
-; -----------------------------------------------------------------------------
-section .text
-global boot_entry
-boot_entry:
-    ; Clear interrupt flag [IF = 0]; 0xFA
-    cli
-    ; To set up a stack, we simply set the esp register to point to the top of
-    ; our stack (as it grows downwards).
-    mov esp, stack_top
-    ; pass the initial ESP
-    push esp
-    ; pass Multiboot info structure
-    push ebx
-    ; pass Multiboot magic number
-    push eax
-    ; Call the boot_main() function inside boot.c
-    call boot_main
-    ; Set interrupt flag [IF = 1]; 0xFA
-    ; Clear interrupts and hang if we return from boot_main
-    cli
-hang:
-    hlt
-    jmp hang
-
-global boot_kernel
-boot_kernel:
-    mov edx, [esp + 4] ; stack_pointer
-    mov ebx, [esp + 8] ; entry
-    mov eax, [esp + 12] ; boot info
-    mov esp, edx ; set stack pointer
-    push eax ; push the boot info
-    call ebx ; call the kernel main
-
-
-; -----------------------------------------------------------------------------
-; SECTION (bss)
-; -----------------------------------------------------------------------------
-section .bss
-align 16
-
-global stack_bottom
-stack_bottom:
-    resb KERNEL_STACK_SIZE
-
-global stack_top
-stack_top:
-    ; the top of the stack is the bottom because the stack counts down

mentos/src/boot.s

@@ -0,0 +1,115 @@
+#                MentOS, The Mentoring Operating system project
+# @file boot.asm
+# @brief Kernel start location, multiboot header
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+                    # All instructions should be 32-bit.
+.extern boot_main   # The start point of our C code
+
+# The magic field should contain this.
+.equ                       MULTIBOOT_HEADER_MAGIC, 0x1BADB002
+# This should be in %eax.
+.equ                       MULTIBOOT_BOOTLOADER_MAGIC, 0x2BADB002
+
+# = Specify what GRUB should PROVIDE =========================================
+# Align the kernel and kernel modules on i386 page (4KB) boundaries.
+.equ                  MULTIBOOT_PAGE_ALIGN, 0x00000001
+# Provide the kernel with memory information.
+.equ                  MULTIBOOT_MEMORY_INFO, 0x00000002
+# Must pass video information to OS.
+.equ                  MULTIBOOT_VIDEO_MODE, 0x00000004
+# -----------------------------------------------------------------------------
+
+# This is the flag combination that we prepare for Grub
+# to read at kernel load time.
+.equ MULTIBOOT_HEADER_FLAGS, (MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO)
+# Grub reads this value to make sure it loads a kernel
+# and not just garbage.
+.equ MULTIBOOT_CHECKSUM, -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
+
+.equ                LOAD_MEMORY_ADDRESS, 0x00000000
+# reserve (1024*1024) for the stack on a doubleword boundary
+.equ                KERNEL_STACK_SIZE, 0x100000
+
+# -----------------------------------------------------------------------------
+# -----------------------------------------------------------------------------
+.pushsection .note.name, "a", @note           
+    .align 4
+    .long 2f - 1f         /* namesz */
+    .long 4f - 3f         /* descsz */
+    .long 18              /* type   */
+1:.asciz "MentOS"         /* name   */
+2:.align 4
+3:.long boot_entry        /* desc   */
+4:.align 4
+.popsection
+
+# -----------------------------------------------------------------------------
+# SECTION (multiboot_header)
+# -----------------------------------------------------------------------------
+.globl multiboot_header
+.align 4
+# This is the GRUB Multiboot header.
+multiboot_header: 
+    # magic
+    .long MULTIBOOT_HEADER_MAGIC
+    # flags
+    .long MULTIBOOT_HEADER_FLAGS
+    # checksum
+    .long MULTIBOOT_CHECKSUM
+
+# -----------------------------------------------------------------------------
+# SECTION (data)
+# -----------------------------------------------------------------------------
+# section .data nobits
+# align 4096
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+.global boot_entry
+boot_entry: 
+    # Clear interrupt flag [IF = 0]; 0xFA
+    cli
+    # To set up a stack, we simply set the esp register to point to the top of
+    # our stack (as it grows downwards).
+    mov $stack_top, %esp
+    # pass the initial ESP
+    push %esp
+    # pass Multiboot info structure
+    push %ebx
+    # pass Multiboot magic number
+    push %eax
+    # Call the boot_main() function inside boot.c
+    call boot_main
+    # Set interrupt flag [IF = 1]; 0xFA
+    # Clear interrupts and hang if we return from boot_main
+    cli
+hang: 
+    hlt
+    jmp hang
+
+.global boot_kernel
+boot_kernel: 
+    mov 4(%esp),%edx  # stack_pointer
+    mov 8(%esp),%ebx  # entry
+    mov 12(%esp),%eax  # boot info
+    mov %edx,%esp # set stack pointer
+    push %eax # push the boot info
+    call *%ebx # call the kernel main
+
+
+# -----------------------------------------------------------------------------
+# SECTION (bss)
+# -----------------------------------------------------------------------------
+.global stack_bottom
+.global stack_top
+.bss
+.align 16
+stack_bottom: 
+    .skip KERNEL_STACK_SIZE
+stack_top: 
+    # the top of the stack is the bottom because the stack counts down
+

mentos/src/descriptor_tables/exception.S

@@ -1,116 +0,0 @@
-;                MentOS, The Mentoring Operating system project
-; @file   exception.asm
-; @brief
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
-
-extern isr_handler
-
-; Macro used to define a ISR which does not push an error code.
-%macro ISR_NOERR 1
-    global INT_%1
-    INT_%1:
-        cli
-        ; A normal ISR stub that pops a dummy error code to keep a
-        ; uniform stack frame
-        push 0
-        push %1
-        jmp isr_common
-%endmacro
-
-; Macro used to define a ISR which pushes an error code.
-%macro ISR_ERR 1
-    global INT_%1
-    INT_%1:
-        cli
-        push %1
-        jmp isr_common
-%endmacro
-
-; -----------------------------------------------------------------------------
-; SECTION (text)
-; -----------------------------------------------------------------------------
-section .text
-
-; Standard X86 interrupt service routines
-ISR_NOERR 0
-ISR_NOERR 1
-ISR_NOERR 2
-ISR_NOERR 3
-ISR_NOERR 4
-ISR_NOERR 5
-ISR_NOERR 6
-ISR_NOERR 7
-ISR_ERR   8
-ISR_NOERR 9
-ISR_ERR   10
-ISR_ERR   11
-ISR_ERR   12
-ISR_ERR   13
-ISR_ERR   14
-ISR_NOERR 15
-ISR_NOERR 16
-ISR_NOERR 17
-ISR_NOERR 18
-ISR_NOERR 19
-ISR_NOERR 20
-ISR_NOERR 21
-ISR_NOERR 22
-ISR_NOERR 23
-ISR_NOERR 24
-ISR_NOERR 25
-ISR_NOERR 26
-ISR_NOERR 27
-ISR_NOERR 28
-ISR_NOERR 29
-ISR_NOERR 30
-ISR_NOERR 31
-
-ISR_NOERR 80
-
-isr_common:
-    ; Save all registers (eax, ecx, edx, ebx, esp, ebp, esi, edi)
-    pusha
-
-    ; Save segment registers
-    push ds
-    push es
-    push fs
-    push gs
-
-    mov ax, 0x10
-    mov ds, ax
-    mov es, ax
-    mov fs, ax
-    mov gs, ax
-    ; CLD - Azzera la flag di Direzione
-    ; Questa istruzione forza semplicemente a zero la flag di Direzione.
-    ; Quando la flag di direzione vale 0 tutte le istruzioni per la
-    ;  manipolazione delle stringhe agiscono in avanti, cioè dagli indirizzi più
-    ;  bassi a quelli più alti.
-    ; L'istruzione agisce dunque sui puntatori SI e DI producendo su essi un
-    ;  autoincremento proporzionale alla dimensione degli operandi trattati.
-    ; Le sue caratteristiche sono riassunte nella seguente tabella (leggi le
-    ;  istruzioni  Legenda della Tabella):
-    cld
-
-    ; Call the interrupt handler.
-    push    esp
-    call    isr_handler
-    add     esp, 0x4
-
-    ; Restore segment registers.
-    pop gs
-    pop fs
-    pop es
-    pop ds
-
-    ; Restore all registers  (eax, ecx, edx, ebx, esp, ebp, esi, edi).
-    popa
-
-    ; Cleanup error code and IRQ #
-    add esp, 0x8
-
-
-    iret                        ; pops 5 things at once:
-                                ;   CS, EIP, EFLAGS, SS, and ESP

mentos/src/descriptor_tables/exception.s

@@ -0,0 +1,116 @@
+#                MentOS, The Mentoring Operating system project
+# @file   exception.asm
+# @brief
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+.extern isr_handler
+
+# Macro used to define a ISR which does not push an error code.
+.macro ISR_NOERR ARG1
+   .globl INT_&ARG1
+    INT_&ARG1:
+        cli
+        # A normal ISR stub that pops a dummy error code to keep a
+        # uniform stack frame
+        push $0
+        push &ARG1
+        jmp isr_common
+.endm
+
+# Macro used to define a ISR which pushes an error code.
+.macro ISR_ERR ARG1
+   .globl INT_&ARG1
+    INT_&ARG1:
+        cli
+        push &ARG1
+        jmp isr_common
+.endm
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+
+# Standard X86 interrupt service routines
+ISR_NOERR 0
+ISR_NOERR 1
+ISR_NOERR 2
+ISR_NOERR 3
+ISR_NOERR 4
+ISR_NOERR 5
+ISR_NOERR 6
+ISR_NOERR 7
+ISR_ERR   8
+ISR_NOERR 9
+ISR_ERR   10
+ISR_ERR   11
+ISR_ERR   12
+ISR_ERR   13
+ISR_ERR   14
+ISR_NOERR 15
+ISR_NOERR 16
+ISR_NOERR 17
+ISR_NOERR 18
+ISR_NOERR 19
+ISR_NOERR 20
+ISR_NOERR 21
+ISR_NOERR 22
+ISR_NOERR 23
+ISR_NOERR 24
+ISR_NOERR 25
+ISR_NOERR 26
+ISR_NOERR 27
+ISR_NOERR 28
+ISR_NOERR 29
+ISR_NOERR 30
+ISR_NOERR 31
+ISR_NOERR 80
+
+isr_common: 
+    # Save all registers (eax, ecx, edx, ebx, esp, ebp, esi, edi)
+    pusha
+
+    # Save segment registers
+    push %ds
+    push %es
+    push %fs
+    push %gs
+
+    mov $0x10,%ax
+    mov %ax,%ds
+    mov %ax,%es
+    mov %ax,%fs
+    mov %ax,%gs
+    # CLD - Azzera la flag di Direzione
+    # Questa istruzione forza semplicemente a zero la flag di Direzione.
+    # Quando la flag di direzione vale 0 tutte le istruzioni per la
+    #  manipolazione delle stringhe agiscono in avanti, cioè dagli indirizzi più
+    #  bassi a quelli più alti.
+    # L'istruzione agisce dunque sui puntatori SI e DI producendo su essi un
+    #  autoincremento proporzionale alla dimensione degli operandi trattati.
+    # Le sue caratteristiche sono riassunte nella seguente tabella (leggi le
+    #  istruzioni  Legenda della Tabella):
+    cld
+
+    # Call the interrupt handler.
+    push   %esp
+    call    isr_handler
+    add    $0x4,%esp
+
+    # Restore segment registers.
+    pop %gs
+    pop %fs
+    pop %es
+    pop %ds
+
+    # Restore all registers  (eax, ecx, edx, ebx, esp, ebp, esi, edi).
+    popa
+
+    # Cleanup error code and IRQ #
+    add $0x8,%esp
+
+
+    iret                        # pops 5 things at once:
+                                #   CS, EIP, EFLAGS, SS, and ESP
+

mentos/src/descriptor_tables/gdt.S

@@ -1,30 +0,0 @@
-;                MentOS, The Mentoring Operating system project
-; @file   gdt.asm
-; @brief
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
-
-global gdt_flush        ; Allows the C code to call gdt_flush().
-
-; -----------------------------------------------------------------------------
-; SECTION (text)
-; -----------------------------------------------------------------------------
-section .text
-
-gdt_flush:
-    mov eax, [esp+4] ; Get the pointer to the GDT, passed as a parameter.
-    lgdt [eax]       ; Load the new GDT pointer
-
-    ; The data segments selectors (registers), can be easily modified using
-    ; simple mov instruction, but the cs can't be used with mov, so you use:
-    jmp 0x08:flush
-    ; to load the segment configurations into the the code segment selector.
-
-flush:
-    mov ax, 0x10     ; 0x10 is the offset in the GDT to our data segment
-    mov ds, ax       ; Load all data segment selectors
-    mov es, ax
-    mov fs, ax
-    mov gs, ax
-    mov ss, ax
-    ret

mentos/src/descriptor_tables/gdt.s

@@ -0,0 +1,28 @@
+#                MentOS, The Mentoring Operating system project
+# @file   gdt.asm
+# @brief
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+.global gdt_flush       # Allows the C code to call gdt_flush().
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+
+gdt_flush: 
+    mov 4(%esp),%eax # Get the pointer to the GDT, passed as a parameter.
+    lgdt (%eax)
+
+    # The data segments selectors (registers), can be easily modified using
+    # simple mov instruction, but the cs can't be used with mov, so you use:
+    mov $0x10,%ax   # 0x10 is the offset in the GDT to our data segment
+    mov %ax,%ds     # Load all data segment selectors
+    mov %ax,%es
+    mov %ax,%fs
+    mov %ax,%gs
+    mov %ax,%ss
+    
+    # to load the segment configurations into the the code segment selector.
+    ret

mentos/src/descriptor_tables/idt.S

@@ -1,17 +0,0 @@
-;                MentOS, The Mentoring Operating system project
-; @file   idt.asm
-; @brief
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
-
-global idt_flush        ; Allows the C code to call idt_flush().
-
-; -----------------------------------------------------------------------------
-; SECTION (text)
-; -----------------------------------------------------------------------------
-section .text
-
-idt_flush:
-    mov  eax, [esp+4]   ; Get the pointer to the IDT, passed as a parameter.
-    lidt [eax]          ; Load the IDT pointer.
-    ret

mentos/src/descriptor_tables/idt.s

@@ -0,0 +1,17 @@
+#                MentOS, The Mentoring Operating system project
+# @file   idt.asm
+# @brief
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+.global idt_flush       # Allows the C code to call idt_flush().
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+
+idt_flush: 
+    mov 4(%esp),%eax   # Get the pointer to the IDT, passed as a parameter.
+    lidt (%eax)
+    ret

mentos/src/descriptor_tables/interrupt.S

@@ -1,28 +1,26 @@
-;                MentOS, The Mentoring Operating system project
+#                MentOS, The Mentoring Operating system project
-; @file   interrupt.asm
+# @file   interrupt.asm
-; @brief
+# @brief
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
+# See LICENSE.md for details.
 
-extern irq_handler
+.extern irq_handler
 
-%macro IRQ 2
+.macro IRQ ARG1, ARG2
-    global IRQ_%1
+    .globl IRQ_&ARG1
-    IRQ_%1:
+    IRQ_&ARG1:
-        cli               ; disable interrupt line
+        cli # disable interrupt line
-        ; A normal ISR stub that pops a dummy error code to keep a
+        push $0
-        ; uniform stack frame
+        push &ARG2
-        push 0
-        push %2           ; irq number
         jmp irq_common
-%endmacro
+.endm
 
-; -----------------------------------------------------------------------------
+# -----------------------------------------------------------------------------
-; SECTION (text)
+# SECTION (text)
-; -----------------------------------------------------------------------------
+# -----------------------------------------------------------------------------
-section .text
+.text
 
-; 32 is the first irq, 47 is the last one. DO NOT CHANGE THESE NUMBERS. 
+# 32 is the first irq, 47 is the last one. DO NOT CHANGE THESE NUMBERS. 
 IRQ 0, 32
 IRQ 1, 33
 IRQ 2, 34
@@ -41,51 +39,51 @@ IRQ 14, 46
 IRQ 15, 47
 
 irq_common: 
-    ;==== Save CPU registers ===================================================
+    # ==== Save CPU registers ===================================================
-    ; when an irq occurs, the following registers are already pushed on stack:
+    # when an irq occurs, the following registers are already pushed on stack:
-    ; eip, cs, eflags, useresp, ss
+    # eip, cs, eflags, useresp, ss
 
-    ; Save registers: eax, ecx, edx, ebx, esp, ebp, esi, edi
+    # Save registers: eax, ecx, edx, ebx, esp, ebp, esi, edi
     pusha
 
-    ; Save segment registers
+    # Save segment registers
-    push ds
+    push %ds
-    push es
+    push %es
-    push fs
+    push %fs
-    push gs
+    push %gs
-    ;---------------------------------------------------------------------------
+    # ---------------------------------------------------------------------------
 
-    ;==== ensure we are using kernel data segment ==============================
+    # ==== ensure we are using kernel data segment ==============================
-    mov ax, 0x10
+    mov $0x10,%ax
-    mov ds, ax
+    mov %ax,%ds
-    mov es, ax
+    mov %ax,%es
-    mov fs, ax
+    mov %ax,%fs
-    mov gs, ax
+    mov %ax,%gs
     cld
-    ;---------------------------------------------------------------------------
+    # ---------------------------------------------------------------------------
 
-    ;==== Call the interrupt handler ===========================================
+    # ==== Call the interrupt handler ===========================================
-    ; The argument passed is a pointer to an Interrupt_State struct,
+    # The argument passed is a pointer to an Interrupt_State struct,
-    ; which describes the stack layout for all interrupts.
+    # which describes the stack layout for all interrupts.
-    push    esp
+    push   %esp
     call    irq_handler
-    add     esp, $4          ; remove esp from stack
+    add    $0x04, %esp        # remove esp from stack
-    ;---------------------------------------------------------------------------
+    # ---------------------------------------------------------------------------
 
-    ;==== Restore registers ====================================================
+    # ==== Restore registers ====================================================
-    ; restore segment registers
+    # restore segment registers
-    pop gs
+    pop %gs
-    pop fs
+    pop %fs
-    pop es
+    pop %es
-    pop ds
+    pop %ds
 
-    ; restore registers: eax, ecx, edx, ebx, esp, ebp, esi, edi
+    # restore registers: eax, ecx, edx, ebx, esp, ebp, esi, edi
     popa
-    ;---------------------------------------------------------------------------
+    # ---------------------------------------------------------------------------
 
-    ; Cleanup error code and IRQ #
+    # Cleanup error code and IRQ #
-    add esp, $8
+    add $0x08, %esp
 
-    ; return to process
+    # return to process
-    iret                        ; pops 5 things at once:
+    iret                        # pops 5 things at once:
-                                ;   CS, EIP, EFLAGS, SS, and ESP
+                                #   CS, EIP, EFLAGS, SS, and ESP

mentos/src/descriptor_tables/interrupt.s

@@ -0,0 +1,89 @@
+#                MentOS, The Mentoring Operating system project
+# @file   interrupt.asm
+# @brief
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+.extern irq_handler
+
+.macro IRQ ARG1, ARG2
+    .globl IRQ_&ARG1
+    IRQ_&ARG1:
+        cli # disable interrupt line
+        push $0
+        push &ARG2
+        jmp irq_common
+.endm
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+
+# 32 is the first irq, 47 is the last one. DO NOT CHANGE THESE NUMBERS. 
+IRQ 0, 32
+IRQ 1, 33
+IRQ 2, 34
+IRQ 3, 35
+IRQ 4, 36
+IRQ 5, 37
+IRQ 6, 38
+IRQ 7, 39
+IRQ 8, 40
+IRQ 9, 41
+IRQ 10, 42
+IRQ 11, 43
+IRQ 12, 44
+IRQ 13, 45
+IRQ 14, 46
+IRQ 15, 47
+
+irq_common: 
+    # ==== Save CPU registers ===================================================
+    # when an irq occurs, the following registers are already pushed on stack:
+    # eip, cs, eflags, useresp, ss
+
+    # Save registers: eax, ecx, edx, ebx, esp, ebp, esi, edi
+    pusha
+
+    # Save segment registers
+    push %ds
+    push %es
+    push %fs
+    push %gs
+    # ---------------------------------------------------------------------------
+
+    # ==== ensure we are using kernel data segment ==============================
+    mov $0x10,%ax
+    mov %ax,%ds
+    mov %ax,%es
+    mov %ax,%fs
+    mov %ax,%gs
+    cld
+    # ---------------------------------------------------------------------------
+
+    # ==== Call the interrupt handler ===========================================
+    # The argument passed is a pointer to an Interrupt_State struct,
+    # which describes the stack layout for all interrupts.
+    push   %esp
+    call    irq_handler
+    add    $0x04, %esp        # remove esp from stack
+    # ---------------------------------------------------------------------------
+
+    # ==== Restore registers ====================================================
+    # restore segment registers
+    pop %gs
+    pop %fs
+    pop %es
+    pop %ds
+
+    # restore registers: eax, ecx, edx, ebx, esp, ebp, esi, edi
+    popa
+    # ---------------------------------------------------------------------------
+
+    # Cleanup error code and IRQ #
+    add $0x08, %esp
+
+    # return to process
+    iret                        # pops 5 things at once:
+                                #   CS, EIP, EFLAGS, SS, and ESP

mentos/src/descriptor_tables/tss.S

@@ -1,17 +0,0 @@
-;                MentOS, The Mentoring Operating system project
-; @file   tss.asm
-; @brief
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
-
-global tss_flush
-
-; -----------------------------------------------------------------------------
-; SECTION (text)
-; -----------------------------------------------------------------------------
-section .text
-
-tss_flush:
-    mov ax, 0x28
-    ltr ax
-    ret

mentos/src/descriptor_tables/tss.s

@@ -0,0 +1,18 @@
+#                MentOS, The Mentoring Operating system project
+# @file   tss.asm
+# @brief
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+.global tss_flush
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+
+tss_flush: 
+    mov $0x28,%ax
+    ltr %ax
+    ret
+

mentos/src/elf/elf.c

@@ -6,7 +6,7 @@
 // Setup the logging for this file (do this before any other include).
 #include "sys/kernel_levels.h"           // Include kernel log levels.
 #define __DEBUG_HEADER__ "[ELF   ]"      ///< Change header.
-#define __DEBUG_LEVEL__  LOGLEVEL_NOTICE ///< Set log level.
+#define __DEBUG_LEVEL__  LOGLEVEL_DEBUG ///< Set log level.
 #include "io/debug.h"                    // Include debugging functions.
 
 #include "assert.h"

mentos/src/kernel.c

@@ -43,28 +43,6 @@ char *module_start[MAX_MODULES];
 /// Describe end address of grub multiboot modules.
 char *module_end[MAX_MODULES];
 
-// Everything is defined in kernel.ld.
-
-/// Points at the multiheader grub info, starting address.
-extern uint32_t _multiboot_header_start;
-/// Points at the multiheader grub info, ending address.
-extern uint32_t _multiboot_header_end;
-/// Points at the kernel code, starting address.
-extern uint32_t _text_start;
-/// Points at the kernel code, ending address.
-extern uint32_t _text_end;
-/// Points at the read-only kernel data, starting address.
-extern uint32_t _rodata_start;
-/// Points at the read-only kernel data, ending address.
-extern uint32_t _rodata_end;
-/// Points at the read-write kernel data initialized, starting address.
-extern uint32_t _data_start;
-/// Points at the read-write kernel data initialized, ending address.
-extern uint32_t _data_end;
-/// Points at the read-write kernel data uninitialized an kernel stack, starting address.
-extern uint32_t _bss_start;
-/// Points at the read-write kernel data uninitialized an kernel stack, ending address.
-extern uint32_t _bss_end;
 /// Points at the top of the kernel stack.
 extern uint32_t stack_top;
 /// Points at the bottom of the kernel stack.
@@ -107,8 +85,8 @@ int kmain(boot_info_t *boot_informations)
     boot_info = *boot_informations;
     // Am I booted by a Multiboot-compliant boot loader?
     if (boot_info.magic != MULTIBOOT_BOOTLOADER_MAGIC) {
-        printf("Invalid magic number: 0x%x\n", boot_info.magic);
+        pr_emerg("Invalid magic number: 0x%x\n", boot_info.magic);
-        return 1;
+        while (1) {}
     }
     // Set the initial esp.
     initial_esp = boot_info.stack_base;
@@ -131,7 +109,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize modules...");
     if (!init_modules(boot_info.multiboot_header)) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -140,7 +118,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize physical memory manager...");
     if (!pmmngr_init(&boot_info)) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -216,7 +194,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize ATA devices...");
     if (ata_initialize()) {
         pr_emerg("Failed to initialize ATA devices!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -225,7 +203,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize EXT2 filesystem...");
     if (ext2_initialize()) {
         pr_emerg("Failed to initialize EXT2 filesystem!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -234,7 +212,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Mount EXT2 filesystem...");
     if (do_mount("ext2", "/", "/dev/hda")) {
         pr_emerg("Failed to mount EXT2 filesystem...\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -244,7 +222,7 @@ int kmain(boot_info_t *boot_informations)
     if (procfs_module_init()) {
         print_fail();
         pr_emerg("Failed to register `procfs`!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -253,7 +231,7 @@ int kmain(boot_info_t *boot_informations)
     printf("    Mounting 'procfs'...");
     if (do_mount("procfs", "/proc", NULL)) {
         pr_emerg("Failed to mount procfs at `/proc`!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -263,7 +241,7 @@ int kmain(boot_info_t *boot_informations)
     if (procv_module_init()) {
         print_fail();
         pr_emerg("Failed to initialize `/proc/video`!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -273,7 +251,7 @@ int kmain(boot_info_t *boot_informations)
     if (procs_module_init()) {
         print_fail();
         pr_emerg("Failed to initialize proc system entries!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -283,7 +261,7 @@ int kmain(boot_info_t *boot_informations)
     if (procipc_module_init()) {
         print_fail();
         pr_emerg("Failed to initialize the IPC information system!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -293,7 +271,7 @@ int kmain(boot_info_t *boot_informations)
     if (sem_init()) {
         print_fail();
         pr_emerg("Failed to initialize the IPC/SEM system!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -303,7 +281,7 @@ int kmain(boot_info_t *boot_informations)
     if (msq_init()) {
         print_fail();
         pr_emerg("Failed to initialize the IPC/MSQ system!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -313,7 +291,7 @@ int kmain(boot_info_t *boot_informations)
     if (shm_init()) {
         print_fail();
         pr_emerg("Failed to initialize the IPC/SHM system!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -328,7 +306,7 @@ int kmain(boot_info_t *boot_informations)
     if (ps2_initialize()) {
         print_fail();
         pr_emerg("Failed to initialize proc system entries!\n");
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -365,7 +343,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Init process management...");
     if (!init_tasking()) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -375,7 +353,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize scheduler feedback system...");
     if (!scheduler_feedback_init()) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 #endif
@@ -385,7 +363,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize scheduler feedback system (2)...");
     if (procfb_module_init()) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -395,7 +373,7 @@ int kmain(boot_info_t *boot_informations)
     task_struct *init_p = process_create_init("/bin/init");
     if (!init_p) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -404,7 +382,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize floating point unit...");
     if (!fpu_install()) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -413,7 +391,7 @@ int kmain(boot_info_t *boot_informations)
     printf("Initialize signals...");
     if (!signals_init()) {
         print_fail();
-        return 1;
+        while (1) {}
     }
     print_ok();
 
@@ -432,5 +410,5 @@ int kmain(boot_info_t *boot_informations)
     for (;;) {}
     // We should not be here.
     pr_emerg("Dear developer, we have to talk...\n");
-    return 1;
+    while (1) {}
 }

mentos/src/process/process.c

@@ -4,10 +4,10 @@
 /// See LICENSE.md for details.
 
 // Setup the logging for this file (do this before any other include).
-#include "sys/kernel_levels.h"           // Include kernel log levels.
+#include "sys/kernel_levels.h"          // Include kernel log levels.
-#define __DEBUG_HEADER__ "[PROC  ]"      ///< Change header.
+#define __DEBUG_HEADER__ "[PROC  ]"     ///< Change header.
-#define __DEBUG_LEVEL__  LOGLEVEL_NOTICE ///< Set log level.
+#define __DEBUG_LEVEL__  LOGLEVEL_DEBUG ///< Set log level.
-#include "io/debug.h"                    // Include debugging functions.
+#include "io/debug.h"                   // Include debugging functions.
 
 #include "assert.h"
 #include "elf/elf.h"
@@ -91,11 +91,15 @@ static int __reset_process(task_struct *task)
         return 0;
     }
 
+    pr_debug("Switching to task page directory.\n");
+
     // Save the current page directory.
     page_directory_t *crtdir = paging_get_current_directory();
     // FIXME: Now to clear the stack a pgdir switch is made, it should be a kernel mmapping.
     paging_switch_directory_va(task->mm->pgd);
 
+    pr_debug("Clean stack (%p).\n", task->mm->start_stack);
+
     // Clean stack space.
     memset((char *)task->mm->start_stack, 0, DEFAULT_STACK_SIZE);
     // Set the base address of the stack.
@@ -105,6 +109,8 @@ static int __reset_process(task_struct *task)
     // Enable the interrupts.
     task->thread.regs.eflags = task->thread.regs.eflags | EFLAG_IF;
 
+    pr_debug("Switching to previous page directory.\n");
+
     // Restore previous pgdir
     paging_switch_directory(crtdir);
 

mentos/src/process/scheduler.c

@@ -517,7 +517,7 @@ pid_t sys_waitpid(pid_t pid, int *status, int options)
     return 0;
 }
 
-void sys_exit(int exit_code)
+void do_exit(int exit_code)
 {
     // Get the current task.
     if (runqueue.curr == NULL) {
@@ -573,6 +573,11 @@ void sys_exit(int exit_code)
     pr_debug("Process %d exited with value %d\n", runqueue.curr->pid, exit_code);
 }
 
+void sys_exit(int exit_code)
+{
+    do_exit(exit_code << 8);
+}
+
 int sys_sched_setparam(pid_t pid, const sched_param_t *param)
 {
     list_head *it;

mentos/src/process/user.S

@@ -1,87 +0,0 @@
-;                MentOS, The Mentoring Operating system project
-; @file   user.asm
-; @brief
-; @copyright (c) 2014-2021 This file is distributed under the MIT License.
-; See LICENSE.md for details.
-
-; Enter userspace (ring3) (from Ring 0, namely Kernel)
-; Usage:  enter_userspace(uintptr_t location, uintptr_t stack);
-; On stack
-; |     stack      | [ebp + 0x0C] ARG1
-; |    location    | [ebp + 0x08] ARG0
-; | return address | [ebp + 0x04]
-; |      EBP       | [ebp + 0x00]
-; |      SS        |
-; |      ESP       |
-; |    EFLAGS      |
-; |      CS        |
-; |      EIP       |
-
-; We can use the following macros to access the arguments ONLY AFTER 0x23 is
-; pushed onto the stack, in fact, the first argument is after 0x08 because
-; we just pushed first `ebp` and then `0x23`.
-%define ARG0 [ebp + 0x08] ; Argument 0
-%define ARG1 [ebp + 0x0C] ; Argument 1
-%define ARG2 [ebp + 0x10] ; Argument 2
-%define ARG3 [ebp + 0x14] ; Argument 3
-%define ARG4 [ebp + 0x18] ; Argument 4
-
-; -----------------------------------------------------------------------------
-; SECTION (text)
-; -----------------------------------------------------------------------------
-section .text
-
-global enter_userspace      ; Allows the C code to call enter_userspace(...).
-
-enter_userspace:
-
-    push ebp                ; Save current ebp
-    mov ebp, esp            ; open a new stack frame
-
-    ;==== Segment selector =====================================================
-    mov ax, 0x23
-    mov ds, ax
-    mov es, ax
-    mov fs, ax
-    mov gs, ax
-    ; we don't need to worry about SS. it's handled by iret
-    ;---------------------------------------------------------------------------
-
-    ; We have to prepare the following stack before executing iret
-    ;    SS           --> Segment selector
-    ;    ESP          --> Stack address
-    ;    EFLAGS       --> CPU state flgas
-    ;    CS           --> Code segment
-    ;    EIP          --> Entry point
-    ;
-
-    ;==== User data segmenet with bottom 2 bits set for ring3 ?=================
-    push 0x23               ; push SS on Kernel's stack
-    ;---------------------------------------------------------------------------
-
-    ;==== (ESP) Stack address ==================================================
-    mov eax, ARG1           ; get uintptr_t stack
-    push eax                ; push process's stack address on Kernel's stack
-    ;---------------------------------------------------------------------------
-
-    ;==== (EFLAGS) =============================================================
-    pushf                   ; push EFLAGS into Kernel's stack
-    pop eax                 ; pop EFLAGS into eax
-    or eax, 0x200           ; enable interrupt
-    push eax                ; push new EFLAGS on Kernel's stack
-    ;---------------------------------------------------------------------------
-
-    ;==== (CS) Code Segment ====================================================
-    push 0x1b               ;
-    ;---------------------------------------------------------------------------
-
-    ;==== (EIP) Entry point ====================================================
-    mov eax, ARG0           ; get uintptr_t location
-    push eax                ; push uintptr_t location on Kernel's stack
-    ;---------------------------------------------------------------------------
-
-    iret                   ; interrupt return
-    pop ebp
-    ret
-
-    ; WE SHOULD NOT STILL BE HERE! :(p

mentos/src/process/user.s

@@ -0,0 +1,78 @@
+#                MentOS, The Mentoring Operating system project
+# @file   user.asm
+# @brief
+# @copyright (c) 2014-2021 This file is distributed under the MIT License.
+# See LICENSE.md for details.
+
+# Enter userspace (ring3) (from Ring 0, namely Kernel)
+# Usage:  enter_userspace(uintptr_t location, uintptr_t stack);
+# On stack
+# |     stack      | [ebp + 0x0C] ARG1
+# |    location    | [ebp + 0x08] ARG0
+# | return address | [ebp + 0x04]
+# |      EBP       | [ebp + 0x00]
+# |      SS        |
+# |      ESP       |
+# |    EFLAGS      |
+# |      CS        |
+# |      EIP       |
+
+# -----------------------------------------------------------------------------
+# SECTION (text)
+# -----------------------------------------------------------------------------
+.text
+
+.global enter_userspace     # Allows the C code to call enter_userspace(...).
+
+enter_userspace: 
+
+    push %ebp              # Save current ebp
+    mov %esp,%ebp          # open a new stack frame
+
+    # ==== Segment selector =====================================================
+    mov $0x23,%ax
+    mov %ax,%ds
+    mov %ax,%es
+    mov %ax,%fs
+    mov %ax,%gs
+    # we don't need to worry about SS. it's handled by iret
+    # ---------------------------------------------------------------------------
+
+    # We have to prepare the following stack before executing iret
+    #    SS           --> Segment selector
+    #    ESP          --> Stack address
+    #    EFLAGS       --> CPU state flgas
+    #    CS           --> Code segment
+    #    EIP          --> Entry point
+    #
+
+    # ==== User data segmenet with bottom 2 bits set for ring3 ?=================
+    push $0x23             # push SS on Kernel's stack
+    # ---------------------------------------------------------------------------
+
+    # ==== (ESP) Stack address ==================================================
+    mov 0x0C(%ebp),%eax            # get uintptr_t stack
+    push %eax              # push process's stack address on Kernel's stack
+    # ---------------------------------------------------------------------------
+
+    # ==== (EFLAGS) =============================================================
+    pushf                   # push EFLAGS into Kernel's stack
+    pop %eax               # pop EFLAGS into eax
+    or $0x200,%eax         # enable interrupt
+    push %eax              # push new EFLAGS on Kernel's stack
+    # ---------------------------------------------------------------------------
+
+    # ==== (CS) Code Segment ====================================================
+    push $0x1b             #
+    # ---------------------------------------------------------------------------
+
+    # ==== (EIP) Entry point ====================================================
+    mov 0x08(%ebp),%eax            # get uintptr_t location
+    push %eax              # push uintptr_t location on Kernel's stack
+    # ---------------------------------------------------------------------------
+
+    iret                   # interrupt return
+    pop %ebp
+    ret
+
+    # WE SHOULD NOT STILL BE HERE! :(p

mentos/src/system/signal.c

@@ -495,38 +495,38 @@ int do_signal(struct pt_regs *f)
 
                 continue;
             case SIGQUIT:
-                sys_exit(GET_EXIT_STATUS(1));
+                do_exit(GET_EXIT_STATUS(1));
                 continue;
             case SIGILL:
-                sys_exit(GET_EXIT_STATUS(132));
+                do_exit(GET_EXIT_STATUS(132));
                 continue;
             case SIGTRAP:
-                sys_exit(GET_EXIT_STATUS(133));
+                do_exit(GET_EXIT_STATUS(133));
                 continue;
             case SIGABRT:
-                sys_exit(GET_EXIT_STATUS(134));
+                do_exit(GET_EXIT_STATUS(134));
                 continue;
             case SIGFPE:
-                sys_exit(GET_EXIT_STATUS(136) | signr);
+                do_exit(GET_EXIT_STATUS(136) | signr);
                 __unlock_task_sighand(current_process);
                 return 1;
             case SIGBUS:
-                sys_exit(GET_EXIT_STATUS(138) | signr);
+                do_exit(GET_EXIT_STATUS(138) | signr);
                 __unlock_task_sighand(current_process);
                 return 1;
             case SIGSEGV:
-                sys_exit(GET_EXIT_STATUS(139) | signr);
+                do_exit(GET_EXIT_STATUS(139) | signr);
                 __unlock_task_sighand(current_process);
                 return 1;
             case SIGXCPU:
-                sys_exit(GET_EXIT_STATUS(158) | signr);
+                do_exit(GET_EXIT_STATUS(158) | signr);
                 __unlock_task_sighand(current_process);
             case SIGXFSZ:
-                sys_exit(GET_EXIT_STATUS(159) | signr);
+                do_exit(GET_EXIT_STATUS(159) | signr);
                 __unlock_task_sighand(current_process);
             case SIGSYS:
             default:
-                sys_exit(GET_EXIT_STATUS(exit_code) | signr);
+                do_exit(GET_EXIT_STATUS(exit_code) | signr);
                 __unlock_task_sighand(current_process);
                 return 1;
             }

programs/CMakeLists.txt

@@ -1,15 +1,42 @@
 # =============================================================================
-# Author: Enrico Fraccaroli
+# BUILD
 # =============================================================================
-# Set the minimum required version of cmake.
+# Add the executables (manually).
-cmake_minimum_required(VERSION 3.1...3.22)
+set(PROGRAMS
-# Initialize the project.
+    nice.c
-project(programs C)
+    ls.c
-
+    mkdir.c
-# =============================================================================
+    ipcrm.c
-# List of programs.
+    login.c
-# =============================================================================
+    man.c
-# Add your file in this list.
+    logo.c
+    shell.c
+    cpuid.c
+    clear.c
+    rmdir.c
+    poweroff.c
+    rm.c
+    cat.c
+    init.c
+    ps.c
+    kill.c
+    edit.c
+    sleep.c
+    date.c
+    echo.c
+    showpid.c
+    uname.c
+    ipcs.c
+    touch.c
+    uptime.c
+    pwd.c
+    env.c
+)
+# Set the directory where the compiled binaries will be placed.
+set(MENTOS_BIN_DIR ${CMAKE_SOURCE_DIR}/files/bin)
+# Create the directory.
+execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${MENTOS_BIN_DIR})
+# Add the executables (manually).
 set(PROGRAMS
     init.c
     cpuid.c
@@ -41,77 +68,72 @@ set(PROGRAMS
     uptime.c
 )
 
-# =============================================================================
+foreach(FILE_NAME ${PROGRAMS})
-# C WARNINGs
-# =============================================================================
-
-# We need to specify the name of the entry function.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -u_start")
-
-# Warning flags.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
-
-# Disable some specific warnings.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-braces")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-command-line-argument")
-
-# Set the compiler options.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
-endif()
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
-elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
-endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-
-# =============================================================================
-# BUILD
-# =============================================================================
-# Set the directory where the compiled binaries will be placed.
-set(MENTOS_BIN_DIR ${CMAKE_SOURCE_DIR}/files/bin)
-
-foreach(PROGRAM ${PROGRAMS})
     # Prepare the program name.
-    string(REPLACE ".c" "" PROGRAM_NAME ${PROGRAM})
+    string(REPLACE ".c" "" EXECUTABLE_NAME ${FILE_NAME})
+    
     # Set the name of the target.
-    set(TARGET_NAME prog_${PROGRAM_NAME})
+    set(TARGET_NAME prog_${EXECUTABLE_NAME})
+
+    # =========================================================================
+    # TEXT ADDRESS
+    # =========================================================================
+    # Randomize .text section address so when debugging symbols don't clash.
+    # The allowed range is from 256MB to 2.75GB
+    # Minimum allowed address: 0x10000000
+    # Max allowed address: 0xB0000000
+    string(MD5 RAND_HASH ${FILE_NAME})
+    string(SUBSTRING ${RAND_HASH} 1 3 TEXADDR_INFIX)
+    string(RANDOM LENGTH 1 ALPHABET 0123456789AB RANDOM_SEED ${RAND_HASH} TEXADDR_FIRST)
+    set(TEXT_ADDR 0x${TEXADDR_FIRST}${TEXADDR_INFIX}0000)
+
+    # =========================================================================
+    # EXECUTABLE
+    # =========================================================================
+    set(TARGET_NAME prog_${EXECUTABLE_NAME})
+
+    # =========================================================================
+    # TEXT ADDRESS
+    # =========================================================================
+    # Randomize .text section address so when debugging symbols don't clash.
+    # The allowed range is from 256MB to 2.75GB
+    # Minimum allowed address: 0x10000000
+    # Max allowed address: 0xB0000000
+    string(MD5 RAND_HASH ${FILE_NAME})
+    string(SUBSTRING ${RAND_HASH} 1 3 TEXADDR_INFIX)
+    string(RANDOM LENGTH 1 ALPHABET 0123456789AB RANDOM_SEED ${RAND_HASH} TEXADDR_FIRST)
+    set(TEXT_ADDR 0x${TEXADDR_FIRST}${TEXADDR_INFIX}0000)
+
+    # =========================================================================
+    # EXECUTABLE
+    # =========================================================================
     # Create the target.
-    add_executable(${TARGET_NAME} ${PROGRAM})
+    add_executable(${TARGET_NAME} ${FILE_NAME})
+    # Add the dependency to libc.
+    add_dependencies(${TARGET_NAME} libc)
     # Add the includes.
     target_include_directories(${TARGET_NAME} PRIVATE ${CMAKE_SOURCE_DIR}/libc/inc)
     # Link the libc library.
-    target_link_libraries(${TARGET_NAME} ${CMAKE_BINARY_DIR}/libc/libc.a)
+    target_link_libraries(${TARGET_NAME} libc)
-    # Add the dependency to libc.
+    # We need to specify the name of the entry function.
-    add_dependencies(${TARGET_NAME} libc)
+    target_compile_options(${TARGET_NAME} PRIVATE -u_start)
-    # Copy the progam to the bin folder.
+    # Add the linking properties.
-    add_custom_command(
+    set_target_properties(${TARGET_NAME} PROPERTIES LINK_FLAGS "-Wl,-Ttext=${TEXT_ADDR},-e_start,-melf_i386")
-        TARGET ${TARGET_NAME}
+    # Set the output directory.
-        BYPRODUCTS ${MENTOS_BIN_DIR}/${PROGRAM_NAME}
+    set_target_properties(${TARGET_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${MENTOS_BIN_DIR}")
-        COMMAND mkdir -p ${MENTOS_BIN_DIR}
+    # Set the output name.
-        COMMAND cp ${PROJECT_BINARY_DIR}/${TARGET_NAME} ${MENTOS_BIN_DIR}/${PROGRAM_NAME}
+    set_target_properties(${TARGET_NAME} PROPERTIES OUTPUT_NAME "${EXECUTABLE_NAME}")
-        DEPENDS ${TARGET_NAME}
+
-    )
+    target_link_libraries(${TARGET_NAME} libc)
+    # We need to specify the name of the entry function.
+    target_compile_options(${TARGET_NAME} PRIVATE -u_start)
+    # Add the linking properties.
+    set_target_properties(${TARGET_NAME} PROPERTIES LINK_FLAGS "-Wl,-Ttext=${TEXT_ADDR},-e_start,-melf_i386")
+    # Set the output directory.
+    set_target_properties(${TARGET_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${MENTOS_BIN_DIR}")
+    # Set the output name.
+    set_target_properties(${TARGET_NAME} PROPERTIES OUTPUT_NAME "${EXECUTABLE_NAME}")
+
     # Append the program name to the list of all the executables.
     list(APPEND ALL_EXECUTABLES ${TARGET_NAME})
 endforeach()

programs/tests/CMakeLists.txt

@@ -1,29 +1,26 @@
 # =============================================================================
-# Author: Enrico Fraccaroli
+# BUILD
 # =============================================================================
-# Set the minimum required version of cmake.
+# Set the directory where the compiled binaries will be placed.
-cmake_minimum_required(VERSION 3.1...3.22)
+set(MENTOS_TESTS_DIR ${CMAKE_SOURCE_DIR}/files/bin/tests)
-# Initialize the project.
+# Create the directory.
-project(tests C)
+execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${MENTOS_TESTS_DIR})
 
-# =============================================================================
+# Add the executables (manually).
-# List of programs.
-# =============================================================================
-# Add your file in this list.
 set(TESTS
     t_mem.c
     t_fork.c
-    # Test real-time programs.
+    # Real-time programs
     t_periodic1.c
     t_periodic2.c
     t_periodic3.c
-    # Testing task execution.
+    # Exec
     t_exec.c
     t_exec_callee.c
     # Test environmental variables.
     t_setenv.c
     t_getenv.c
-    # Test signals.
+    # Test: signals.
     t_stopcont.c
     t_sigusr.c
     t_abort.c
@@ -37,91 +34,47 @@ set(TESTS
     t_kill.c
     t_itimer.c
     t_gid.c
-    # Test semaphores.
-    t_semget.c
-    t_semflg.c
-    t_semop.c
-    # Test message queues.
-    t_msgget.c
-    # Test shared memory.
-    t_shmget.c
-    t_shm_read.c
-    t_shm_write.c
-    # Test scheduling feedback tests.
-    t_schedfb.c
 )
 
-# =============================================================================
+foreach(FILE_NAME ${TESTS})
-# C WARNINGs
-# =============================================================================
-
-# We need to specify the name of the entry function.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -u_start")
-
-# Warning flags.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wshadow")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
-
-# Disable some specific warnings.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-variable")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unknown-pragmas")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-braces")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-command-line-argument")
-
-# Set the compiler options.
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdlib")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostdinc")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-builtin")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-stack-protector")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-pic")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
-endif()
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")
-elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
-endif(CMAKE_BUILD_TYPE STREQUAL "Debug")
-
-# =============================================================================
-# BUILD
-# =============================================================================
-# Set the directory where the compiled binaries will be placed.
-set(MENTOS_TESTS_DIR ${CMAKE_SOURCE_DIR}/files/bin/tests)
-
-foreach(TEST ${TESTS})
     # Prepare the program name.
-    string(REPLACE ".c" "" TEST_NAME ${TEST})
+    string(REPLACE ".c" "" EXECUTABLE_NAME ${FILE_NAME})
+    
     # Set the name of the target.
-    set(TARGET_NAME test_${TEST_NAME})
+    set(TARGET_NAME test_${EXECUTABLE_NAME})
+
+    # =========================================================================
+    # TEXT ADDRESS
+    # =========================================================================
+    # Randomize .text section address so when debugging symbols don't clash.
+    # The allowed range is from 256MB to 2.75GB
+    # Minimum allowed address: 0x10000000
+    # Max allowed address: 0xB0000000
+    string(MD5 RAND_HASH ${FILE_NAME})
+    string(SUBSTRING ${RAND_HASH} 1 3 TEXADDR_INFIX)
+    string(RANDOM LENGTH 1 ALPHABET 0123456789AB RANDOM_SEED ${RAND_HASH} TEXADDR_FIRST)
+    set(TEXT_ADDR 0x${TEXADDR_FIRST}${TEXADDR_INFIX}0000)
+
+    # =========================================================================
+    # EXECUTABLE
+    # =========================================================================
     # Create the target.
-    add_executable(${TARGET_NAME} ${TEST})
+    add_executable(${TARGET_NAME} ${CMAKE_SOURCE_DIR}/programs/tests/${FILE_NAME})
+    # Add the dependency to libc.
+    add_dependencies(${TARGET_NAME} libc)
     # Add the includes.
     target_include_directories(${TARGET_NAME} PRIVATE ${CMAKE_SOURCE_DIR}/libc/inc)
     # Link the libc library.
-    target_link_libraries(${TARGET_NAME} ${CMAKE_BINARY_DIR}/libc/libc.a)
+    target_link_libraries(${TARGET_NAME} libc)
-    # Add the dependency to libc.
+    # We need to specify the name of the entry function.
-    add_dependencies(${TARGET_NAME} libc)
+    target_compile_options(${TARGET_NAME} PRIVATE -u_start)
-    # Copy the progam to the bin folder.
+    # Add the linking properties.
-    add_custom_command(
+    set_target_properties(${TARGET_NAME} PROPERTIES LINK_FLAGS "-Wl,-Ttext=${TEXT_ADDR},-e_start,-melf_i386")
-        TARGET ${TARGET_NAME}
+    # Set the output directory.
-        BYPRODUCTS ${MENTOS_TESTS_DIR}/${TEST_NAME}
+    set_target_properties(${TARGET_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${MENTOS_TESTS_DIR}")
-        COMMAND mkdir -p ${MENTOS_TESTS_DIR}
+    # Set the output name.
-        COMMAND cp ${PROJECT_BINARY_DIR}/${TARGET_NAME} ${MENTOS_TESTS_DIR}/${TEST_NAME}
+    set_target_properties(${TARGET_NAME} PROPERTIES OUTPUT_NAME "${EXECUTABLE_NAME}")
-        DEPENDS ${TARGET_NAME}
+
-    )
     # Append the program name to the list of all the executables.
     list(APPEND ALL_TESTS ${TARGET_NAME})
 endforeach()

programs/tests/t_abort.c

@@ -16,7 +16,6 @@ void sig_handler(int sig)
 {
     printf("handler(%d) : Starting handler.\n", sig);
     if (sig == SIGABRT) {
-
         static int counter = 0;
         counter += 1;
 
@@ -38,8 +37,10 @@ int main(int argc, char *argv[])
 
     if (sigaction(SIGABRT, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGABRT, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     abort();
+
+    return EXIT_SUCCESS;
 }

programs/tests/t_alarm.c

@@ -39,12 +39,11 @@ int main(int argc, char *argv[])
     action.sa_handler = alarm_handler;
     if (sigaction(SIGALRM, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGALRM, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
-
     alarm(5);
-    while(1) { }
+    while (1) {}
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_exec.c

@@ -22,12 +22,12 @@ int main(int argc, char *argv[])
     int status;
     if (argc != 2) {
         __print_usage(argc, argv);
-        return 1;
+        return EXIT_FAILURE;
     }
 
     if (setenv("ENV_VAR", "pwd0", 0) == -1) {
         printf("Failed to set env: `ENV_VAR`\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     char *file        = "echo";
@@ -54,11 +54,11 @@ int main(int argc, char *argv[])
             execvpe(file, exec_argv, exec_envp);
         } else {
             __print_usage(argc, argv);
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("Exec failed.\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     wait(&status);
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_exec_callee.c

@@ -11,8 +11,8 @@ int main(int argc, char *argv[])
     char *ENV_VAR = getenv("ENV_VAR");
     if (ENV_VAR == NULL) {
         printf("Failed to get env: `ENV_VAR`\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ENV_VAR = %s\n", ENV_VAR);
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_fork.c

@@ -12,7 +12,7 @@
 int main(int argc, char *argv[])
 {
     if (argc != 2) {
-        return 1;
+        return EXIT_FAILURE;
     }
     char *ptr;
     int N;
@@ -61,5 +61,5 @@ int main(int argc, char *argv[])
         break;
     }
 #endif
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_getenv.c

@@ -13,8 +13,8 @@ int main(int argc, char *argv[])
     char *ENV_VAR = getenv("ENV_VAR");
     if (ENV_VAR == NULL) {
         printf("Failed to get env: `ENV_VAR`\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ENV_VAR = %s\n", ENV_VAR);
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_gid.c

@@ -39,14 +39,14 @@ int main(int argc, char **argv)
     group_t *root_group = getgrgid(0);
     if (strcmp(root_group->gr_name, "root") != 0) {
         printf("Error in getgrgid function.");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     root_group = getgrnam("root");
     if (root_group->gr_gid != 0) {
         printf("Error in getgrnam function.");
-        return 1;
+        return EXIT_FAILURE;
     }
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_groups.c

@@ -27,12 +27,12 @@ int main(int argc, char **argv)
             printf("%d) pid_child: %d, gid_child: %d, ppid_child: %d, sid_child: %d\n",
                    i, pid_child, gid_child, ppid_child, sid_child);
             sleep(5);
-            exit(0);
+            return EXIT_SUCCESS;
         }
     }
     //int status;
     //while (wait(&status) > 0)
     //    ;
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_itimer.c

@@ -49,7 +49,7 @@ int main(int argc, char *argv[])
     action.sa_handler = alarm_handler;
     if (sigaction(SIGALRM, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGALRM, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     itimerval interval = { 0 };
@@ -57,5 +57,5 @@ int main(int argc, char *argv[])
     setitimer(ITIMER_REAL, &interval, NULL);
 
     while(1) { }
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_kill.c

@@ -48,7 +48,7 @@ int main(int argc, char *argv[])
         action.sa_handler = child_sigusr1_handler;
         if (sigaction(SIGUSR1, &action, NULL) == -1) {
             printf("Failed to set signal handler (%s).\n", SIGUSR1, strerror(errno));
-            return 1;
+            return EXIT_FAILURE;
         }
         child_process();
     } else {
@@ -61,5 +61,5 @@ int main(int argc, char *argv[])
     int status;
     wait(&status);
     printf("main : end (%d)\n", status);
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_mem.c

@@ -14,7 +14,7 @@ int main(int argc, char *argv[])
 {
     if (argc != 3) {
         printf("%s: You must provide 2 dimensions.\n", argv[0]);
-        return 1;
+        return EXIT_FAILURE;
     }
     char *ptr;
     int rows = strtol(argv[1], &ptr, 10);
@@ -48,5 +48,5 @@ int main(int argc, char *argv[])
 
     sleep(5);
     pr_warning("Exiting!\n");
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_msgget.c

@@ -58,7 +58,7 @@ int main(int argc, char *argv[])
     key = ftok("/home/user/test7.txt", 5);
     if (key < 0) {
         perror("Failed to generate key using ftok");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("Generated key using ftok (key = %d)\n", key);
 
@@ -67,7 +67,7 @@ int main(int argc, char *argv[])
     msqid = msgget(key, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
     if (msqid < 0) {
         perror("Failed to create message queue");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("Created message queue (id : %d)\n", msqid);
 
@@ -81,7 +81,7 @@ int main(int argc, char *argv[])
         sleep(3);
         // Send the message.
         __send_message(msqid, 1, &message, "General Kenobi...");
-        return 0;
+        return EXIT_SUCCESS;
     }
     // Receive the message.
     __receive_message(msqid, 1, &message);
@@ -106,5 +106,5 @@ int main(int argc, char *argv[])
         perror("Failed to remove message queue.");
     }
     printf("Correctly removed message queue.\n");
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_periodic1.c

@@ -3,10 +3,11 @@
 /// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include <stdio.h>
-#include <sched.h>
 #include <sys/unistd.h>
 #include <strerror.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sched.h>
 
 int main(int argc, char *argv[])
 {
@@ -42,5 +43,5 @@ int main(int argc, char *argv[])
             break;
         }
     }
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_periodic2.c

@@ -3,10 +3,11 @@
 /// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include <stdio.h>
-#include <sched.h>
 #include <sys/unistd.h>
 #include <strerror.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sched.h>
 
 int main(int argc, char *argv[])
 {
@@ -30,5 +31,5 @@ int main(int argc, char *argv[])
             break;
         }
     }
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_periodic3.c

@@ -3,10 +3,11 @@
 /// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
 
-#include <stdio.h>
-#include <sched.h>
 #include <sys/unistd.h>
 #include <strerror.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sched.h>
 
 int main(int argc, char *argv[])
 {
@@ -30,5 +31,5 @@ int main(int argc, char *argv[])
             break;
         }
     }
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_schedfb.c

@@ -5,6 +5,7 @@
 
 #include <sys/unistd.h>
 #include <sys/wait.h>
+#include <stdlib.h>
 #include <stdio.h>
 
 int main(int argc, char *argv[])
@@ -14,9 +15,9 @@ int main(int argc, char *argv[])
     for (int i = 0; i < 10; ++i) {
         if ((cpid = fork()) == 0) {
             execl("/bin/tests/t_alarm", "t_alarm", NULL);
-            return 0;
+            return EXIT_SUCCESS;
         }
     }
     while (wait(NULL) != -1) continue;
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_semflg.c

@@ -26,7 +26,7 @@ int main(int argc, char *argv[])
     semid = semget(IPC_PRIVATE, 1, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
     if (semid < 0) {
         perror("Failed to create semaphore set");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Created semaphore set (semid : %d)\n", semid);
 
@@ -37,7 +37,7 @@ int main(int argc, char *argv[])
     ret = semctl(semid, 0, SETVAL, &arg);
     if (ret < 0) {
         perror("Failed to set value of semaphore");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Set semaphore value (id : %d, value : %d == 1)\n", semid, arg.val);
 
@@ -46,7 +46,7 @@ int main(int argc, char *argv[])
     ret = semctl(semid, 0, GETVAL, NULL);
     if (ret < 0) {
         perror("Failed to get the value of semaphore set");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Get semaphore value (id : %d, value : %d == 1)\n", semid, ret);
 
@@ -65,7 +65,7 @@ int main(int argc, char *argv[])
         // Increment semaphore value.
         if (semop(semid, &op_child, 1) < 0) {
             perror("Failed to perform first child operation");
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("[child] Succesfully performed opeation (id : %d)\n", semid);
 
@@ -74,7 +74,7 @@ int main(int argc, char *argv[])
         ret = semctl(semid, 0, GETVAL, NULL);
         if (ret < 0) {
             perror("Failed to get the value of semaphore set");
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("[child] Get semaphore value (id : %d, value : %d == 1)\n", semid, ret);
         printf("[child] Exit, now.\n", semid, ret);
@@ -87,14 +87,14 @@ int main(int argc, char *argv[])
         }
         printf("[child] Correctly removed semaphore set.\n");
 
-        return 0;
+        return EXIT_SUCCESS;
     }
 
     // ========================================================================
     // Perform the operations.
     if (semop(semid, op, 2) < 0) {
         perror("Failed to perform operation");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Performed semaphore operations (id : %d)\n", semid);
 
@@ -103,7 +103,7 @@ int main(int argc, char *argv[])
     ret = semctl(semid, 0, GETVAL, NULL);
     if (ret < 0) {
         perror("Failed to get the value of semaphore set");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Get semaphore value (id : %d, value : %d == 1)\n", semid, ret);
 
@@ -115,5 +115,5 @@ int main(int argc, char *argv[])
     }
     printf("[father] Correctly removed semaphore set.\n");
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_semget.c

@@ -26,7 +26,7 @@ int main(int argc, char *argv[])
     key = ftok("/home/user/test7.txt", 5);
     if (key < 0) {
         perror("Failed to generate key using ftok.");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("Generated key using ftok (key = %d)\n", key);
 
@@ -35,7 +35,7 @@ int main(int argc, char *argv[])
     semid = semget(key, 1, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
     if (semid < 0) {
         perror("Failed to create semaphore set.");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Created semaphore set (id : %d)\n", semid);
 
@@ -46,7 +46,7 @@ int main(int argc, char *argv[])
     ret = semctl(semid, 0, SETVAL, &arg);
     if (ret < 0) {
         perror("Failed to set value of semaphore.");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Set semaphore value (id : %d, value : %d == 1)\n", semid, arg.val);
 
@@ -55,7 +55,7 @@ int main(int argc, char *argv[])
     ret = semctl(semid, 0, GETVAL, NULL);
     if (ret < 0) {
         perror("Failed to get the value of semaphore set.");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Get semaphore value (id : %d, value : %d == 1)\n", semid, ret);
 
@@ -71,7 +71,7 @@ int main(int argc, char *argv[])
         sleep(3);
         if (semop(semid, &op_child, 1) < 0) {
             perror("Failed to perform first child operation.");
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("[child] Succesfully performed opeation (id : %d)\n", semid);
 
@@ -79,7 +79,7 @@ int main(int argc, char *argv[])
         ret = semctl(semid, 0, GETVAL, NULL);
         if (ret < 0) {
             perror("Failed to get the value of semaphore set.");
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("[child] Get semaphore value (id : %d, value : %d == 0)\n", semid, ret);
 
@@ -87,7 +87,7 @@ int main(int argc, char *argv[])
         sleep(3);
         if (semop(semid, &op_child, 1) < 0) {
             perror("Failed to perform second child operation.");
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("[child] Succesfully performed opeation (id : %d)\n", semid);
 
@@ -95,14 +95,14 @@ int main(int argc, char *argv[])
         ret = semctl(semid, 0, GETVAL, NULL);
         if (ret < 0) {
             perror("Failed to get the value of semaphore set.");
-            return 1;
+            return EXIT_FAILURE;
         }
         printf("[child] Get semaphore value (id : %d, value : %d == 0)\n", semid, ret);
 
         printf("[child] Exit, now.\n", semid, ret);
 
         // Exit with the child process.
-        return 0;
+        return EXIT_SUCCESS;
     }
 
     // ========================================================================
@@ -121,7 +121,7 @@ int main(int argc, char *argv[])
     // Perform the operations.
     if (semop(semid, op_father, 3) < 0) {
         perror("Failed to perform father operation.");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     sleep(2);
@@ -132,7 +132,7 @@ int main(int argc, char *argv[])
     ret = semctl(semid, 0, GETVAL, NULL);
     if (ret < 0) {
         perror("Failed to get the value of semaphore set.");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("[father] Get semaphore value (id : %d, value : %d == 0)\n", semid, ret);
 
@@ -143,5 +143,5 @@ int main(int argc, char *argv[])
     }
     printf("[father] Correctly removed semaphore set.\n");
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_semop.c

@@ -52,7 +52,7 @@ int main(int argc, char *argv[])
 
     if (semctl(semid, 0, SETALL, &arg) == -1) {
         perror("Failed to set semaphores");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     if (!fork()) {
@@ -82,7 +82,7 @@ int main(int argc, char *argv[])
     }
     if (semctl(semid, 0, IPC_RMID, 0) == -1) {
         perror("Failed to remove IPC");
-        return 1;
+        return EXIT_FAILURE;
     }
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_setenv.c

@@ -15,7 +15,7 @@ int main(int argc, char *argv[])
 
     if (setenv("ENV_VAR", "pwd0", 0) == -1) {
         printf("Failed to set env: `PWD`\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     if (fork() == 0) {
@@ -24,5 +24,5 @@ int main(int argc, char *argv[])
     }
 
     wait(&status);
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_sigaction.c

@@ -33,7 +33,7 @@ int main(int argc, char *argv[])
     action.sa_handler = sigusr1_handler;
     if (sigaction(SIGUSR1, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGUSR1, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     printf("main : Calling handler (%d).\n", SIGUSR1);
@@ -41,8 +41,9 @@ int main(int argc, char *argv[])
     int ret = kill(getpid(), SIGUSR1);
     printf("main : Returning from handler (%d): %d.\n", SIGUSR1, ret);
     printf("main : value : %d\n", values);
-    for (int i = 0; i < 4; ++i)
+    for (int i = 0; i < 4; ++i) {
         printf("values[%d] : `%d`\n", i, values[i]);
+    }
     free(values);
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_sigfpe.c

@@ -45,7 +45,7 @@ int main(int argc, char *argv[])
 
     if (sigaction(SIGFPE, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGFPE, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     printf("Diving by zero (unrecoverable)...\n");
@@ -57,4 +57,5 @@ int main(int argc, char *argv[])
     d /= e;
     e -= 1;
     printf("d: %d, e: %d\n", d, e);
+    return EXIT_SUCCESS;
 }

programs/tests/t_siginfo.c

@@ -36,7 +36,7 @@ int main(int argc, char *argv[])
 
     if (sigaction(SIGFPE, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGFPE, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     printf("Diving by zero (unrecoverable)...\n");
@@ -48,4 +48,5 @@ int main(int argc, char *argv[])
         e -= 1;
     }
     printf("d: %d, e: %d\n", d, e);
+    return EXIT_SUCCESS;
 }

programs/tests/t_sigmask.c

@@ -25,7 +25,7 @@ int main(int argc, char *argv[])
     action.sa_handler = sigusr1_handler;
     if (sigaction(SIGUSR1, &action, NULL) == -1) {
         printf("Failed to set signal handler (%d, %s).\n", SIGUSR1, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     printf("main : Blocking signal (%d).\n", SIGUSR1);
@@ -45,5 +45,5 @@ int main(int argc, char *argv[])
     ret = kill(getpid(), SIGUSR1);
     printf("main : Returning from handler (%d): %d.\n", SIGUSR1, ret);
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_sigusr.c

@@ -38,12 +38,12 @@ int main(int argc, char *argv[])
 
     if (sigaction(SIGUSR1, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGUSR1, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     if (sigaction(SIGUSR2, &action, NULL) == -1) {
         printf("Failed to set signal handler (%s).\n", SIGUSR2, strerror(errno));
-        return 1;
+        return EXIT_FAILURE;
     }
 
     kill(getpid(), SIGUSR1);
@@ -51,5 +51,6 @@ int main(int argc, char *argv[])
     kill(getpid(), SIGUSR2);
 
     while(1) { };
-    return 0;
+
+    return EXIT_SUCCESS;
 }

programs/tests/t_sleep.c

@@ -17,5 +17,5 @@ int main(int argc, char *argv[])
     sleep(4);
     printf("COMPLETED.\n");
 
-    return 0;
+    return EXIT_SUCCESS;
 }

programs/tests/t_stopcont.c

@@ -31,7 +31,7 @@ int main(int argc, char *argv[])
     action.sa_handler = wait_for_child;
     if (sigaction(SIGCHLD, &action, NULL) == -1) {
         printf("Failed to set signal handler. %d\n", SIGCHLD);
-        return 1;
+        return EXIT_FAILURE;
     }
 
     child_pid = fork();
@@ -55,5 +55,5 @@ int main(int argc, char *argv[])
         }
     }
 
-    return 0;
+    return EXIT_SUCCESS;
 }