Merge branch 'develop' into feature/remove_nasm

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
-    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

libc/CMakeLists.txt

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

mentos/CMakeLists.txt

@@ -1,19 +1,9 @@
-# =============================================================================
-# Author: Enrico Fraccaroli
-# =============================================================================
-
-# 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
@@ -28,164 +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
-# =============================================================================
-
-# 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 "${CMAKE_C_FLAGS} -m32")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-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")
-
 # =============================================================================
 # 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})
@@ -203,6 +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.
@@ -280,8 +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(
@@ -294,16 +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/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
@@ -40,52 +38,52 @@ IRQ 13, 45
 IRQ 14, 46
 IRQ 15, 47
 
-irq_common:
+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/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

programs/CMakeLists.txt

@@ -1,57 +1,3 @@
-# =============================================================================
-# Author: Enrico Fraccaroli
-# =============================================================================
-
-# Set the minimum required version of cmake.
-cmake_minimum_required(VERSION 3.1...3.22)
-
-# Initialize the project.
-project(programs C)
-
-# =============================================================================
-# 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")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
-    set(CMAKE_C_FLAGS "${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")
-
 # =============================================================================
 # BUILD
 # =============================================================================
@@ -88,11 +34,44 @@ set(PROGRAMS
 )
 # 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
+    clear.c
+    date.c
+    ls.c
+    logo.c
+    nice.c
+    poweroff.c
+    rm.c
+    shell.c
+    uname.c
+    cat.c
+    echo.c
+    login.c
+    mkdir.c
+    pwd.c
+    rmdir.c
+    showpid.c
+    touch.c
+    env.c
+    ps.c
+    kill.c
+    ipcrm.c
+    ipcs.c
+    sleep.c
+    man.c
+    edit.c
+    uptime.c
+)
 
 foreach(FILE_NAME ${PROGRAMS})
     # Prepare the program name.
     string(REPLACE ".c" "" EXECUTABLE_NAME ${FILE_NAME})
-
+    
     # Set the name of the target.
     set(TARGET_NAME prog_${EXECUTABLE_NAME})
 
@@ -108,11 +87,28 @@ foreach(FILE_NAME ${PROGRAMS})
     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} ${CMAKE_SOURCE_DIR}/programs/${FILE_NAME})
+    add_executable(${TARGET_NAME} ${FILE_NAME})
     # Add the dependency to libc.
     add_dependencies(${TARGET_NAME} libc)
     # Add the includes.
@@ -128,6 +124,16 @@ foreach(FILE_NAME ${PROGRAMS})
     # Set the output name.
     set_target_properties(${TARGET_NAME} PROPERTIES OUTPUT_NAME "${EXECUTABLE_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

@@ -1,95 +1,40 @@
-# =============================================================================
-# Author: Enrico Fraccaroli
-# =============================================================================
-
-# Set the minimum required version of cmake.
-cmake_minimum_required(VERSION 3.1...3.22)
-
-# Initialize the project.
-project(tests C)
-
-# =============================================================================
-# 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")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=i686")
-if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10)
-    set(CMAKE_C_FLAGS "${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")
-
 # =============================================================================
 # BUILD
 # =============================================================================
-# Add your file in this list.
-set(TESTS
-    t_gid.c
-    t_alarm.c
-    t_periodic3.c
-    t_setenv.c
-    t_itimer.c
-    t_fork.c
-    t_semget.c
-    t_exec.c
-    t_sleep.c
-    t_periodic2.c
-    t_sigfpe.c
-    t_sigmask.c
-    t_getenv.c
-    t_sigusr.c
-    t_exec_callee.c
-    t_shmget.c
-    t_stopcont.c
-    t_semop.c
-    t_sigaction.c
-    t_schedfb.c
-    t_siginfo.c
-    t_groups.c
-    t_semflg.c
-    t_abort.c
-    t_msgget.c
-    t_periodic1.c
-    t_kill.c
-    t_shm_write.c
-    t_mem.c
-    t_shm_read.c
-)
 # Set the directory where the compiled binaries will be placed.
 set(MENTOS_TESTS_DIR ${CMAKE_SOURCE_DIR}/files/bin/tests)
+# Create the directory.
+execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${MENTOS_TESTS_DIR})
+
+# Add the executables (manually).
+set(TESTS
+    t_mem.c
+    t_fork.c
+    # Real-time programs
+    t_periodic1.c
+    t_periodic2.c
+    t_periodic3.c
+    # Exec
+    t_exec.c
+    t_exec_callee.c
+    # Test environmental variables.
+    t_setenv.c
+    t_getenv.c
+    # Test: signals.
+    t_stopcont.c
+    t_sigusr.c
+    t_abort.c
+    t_sigfpe.c
+    t_siginfo.c
+    t_sleep.c
+    t_sigaction.c
+    t_sigmask.c
+    t_groups.c
+    t_alarm.c
+    t_kill.c
+    t_itimer.c
+    t_gid.c
+)
 
 foreach(FILE_NAME ${TESTS})
     # Prepare the program name.

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;
 }