build.bat

@echo off
setlocal enabledelayedexpansion

REM Kill any existing QEMU instances to prevent file locking issues
taskkill /f /im qemu-system-x86_64.exe >nul 2>&1

set NASM=tools\nasm\nasm-2.16.03\nasm.exe
set GCC=tools\i686-elf-tools\bin\i686-elf-gcc.exe
set LD=tools\i686-elf-tools\bin\i686-elf-ld.exe
set QEMU="C:\Program Files\qemu\qemu-system-x86_64.exe"
set QEMU_IMG="C:\Program Files\qemu\qemu-img.exe"

set CFLAGS=-O2 -ffreestanding -fno-pie -fno-stack-protector

echo Compiling C Kernel Entry...
%NASM% -f elf src\kernel_entry.asm -o kernel_entry.o
if %errorlevel% neq 0 ( 
    echo [ERROR] Failed to compile kernel entry.
    pause
    exit /b
)

echo Compiling Interrupts ASM...
%NASM% -f elf src\interrupt.asm -o interrupt.o
%NASM% -f elf src\gdt_flush.asm -o gdt_flush.o
if %errorlevel% neq 0 (
    echo [ERROR] Failed to compile Interrupt ASM.
    pause
    exit /b
)

echo Compiling C Kernel ^& Drivers...
%GCC% %CFLAGS% -c src\kernel.c -o kernel.o
%GCC% %CFLAGS% -c src\screen.c -o screen.o
%GCC% %CFLAGS% -c src\ports.c -o ports.o
%GCC% %CFLAGS% -c src\idt.c -o idt.o
%GCC% %CFLAGS% -c src\isr.c -o isr.o
%GCC% %CFLAGS% -c src\keyboard.c -o keyboard.o
%GCC% %CFLAGS% -c src\mouse.c -o mouse.o
%GCC% %CFLAGS% -c src\window.c -o window.o
%GCC% %CFLAGS% -c src\font.c -o font.o
%GCC% %CFLAGS% -c src\string.c -o string.o
%GCC% %CFLAGS% -c src\serial.c -o serial.o
%GCC% %CFLAGS% -c src\system_calls.c -o system_calls.o
%GCC% %CFLAGS% -c src\syscall_handler.c -o syscall_handler.o
%GCC% %CFLAGS% -c src\shell.c -o shell.o
%GCC% %CFLAGS% -c src\panic.c -o panic.o
%GCC% %CFLAGS% -c src\pmm.c -o pmm.o
%GCC% %CFLAGS% -c src\vmm.c -o vmm.o
%GCC% %CFLAGS% -c src\gdt.c -o gdt.o
%GCC% %CFLAGS% -c src\ata.c -o ata.o
%GCC% %CFLAGS% -c src\timer.c -o timer.o
%GCC% %CFLAGS% -c src\process.c -o process.o
%GCC% %CFLAGS% -c src\fat16.c -o fat16.o
%GCC% %CFLAGS% -c src\elf.c -o elf.o
%GCC% %CFLAGS% -c src\kmalloc.c -o kmalloc.o
if %errorlevel% neq 0 (
    echo [ERROR] Failed to compile C kernel/drivers.
    pause
    exit /b
)

echo Compiling User Space C Library (libc)...
%GCC% %CFLAGS% -Iapps/libc -c apps\libc\string.c -o apps\libc\string.o
%GCC% %CFLAGS% -Iapps/libc -c apps\libc\stdlib.c -o apps\libc\stdlib.o
%GCC% %CFLAGS% -Iapps/libc -c apps\libc\stdio.c -o apps\libc\stdio.o
%GCC% %CFLAGS% -Iapps/libc -c apps\libc\errno.c -o apps\libc\errno.o
%GCC% %CFLAGS% -Iapps/libc -c apps\libc\math.c -o apps\libc\math.o
%GCC% %CFLAGS% -Iapps/libc -c apps\libc\unistd.c -o apps\libc\unistd.o
if %errorlevel% neq 0 (
    echo [ERROR] Failed to compile libc!
    pause
    exit /b
)

echo Compiling User Space Apps...
%NASM% -f elf apps\crt0.asm -o apps\crt0.o
%GCC% %CFLAGS% -Iapps/libc -c apps\hello.c -o apps\hello.o
%LD% -T apps\linker.ld -o tools\hello.elf apps\crt0.o apps\hello.o apps\libc\string.o apps\libc\stdlib.o apps\libc\stdio.o apps\libc\errno.o
if %errorlevel% neq 0 (
    echo [ERROR] Failed to build hello.elf!
    pause
    exit /b
)

echo Compiling Doom...
cd apps\doom
call doom_build.bat
if %errorlevel% neq 0 (
    echo [ERROR] Failed to compile Doom!
    cd ..\..
    exit /b
)
cd ..\..
call link_doom.bat
if %errorlevel% neq 0 (
    echo [ERROR] Failed to link DOOM.ELF!
    pause
    exit /b
)
copy /Y tools\DOOM.ELF apps\doom\tools\DOOM.ELF >nul 2>&1
echo DOOM.ELF successfully built!

echo Linking Kernel...
%LD% -T linker.ld -o kernel.bin kernel_entry.o interrupt.o gdt_flush.o gdt.o ata.o kernel.o screen.o ports.o idt.o isr.o keyboard.o mouse.o window.o font.o string.o serial.o system_calls.o syscall_handler.o shell.o panic.o pmm.o vmm.o timer.o process.o fat16.o elf.o kmalloc.o --oformat binary
if %errorlevel% neq 0 (
    echo [ERROR] Failed to link kernel.
    pause
    exit /b
)

REM Auto-calculate the number of 512-byte sectors needed to load kernel.bin
for %%A in (kernel.bin) do set KSIZE=%%~zA
set /a SECTORS=(%KSIZE% + 511) / 512
echo Kernel is %KSIZE% bytes = %SECTORS% sectors

echo Compiling Bootloader (with KERNEL_SECTORS=%SECTORS%)...
%NASM% -i src\ -f bin -dKERNEL_SECTORS=%SECTORS% src\bootsect.asm -o bootsect.bin
if %errorlevel% neq 0 (
    echo [ERROR] Failed to compile bootloader.
    pause
    exit /b
)

echo Building OS Image...
copy /b /Y bootsect.bin + kernel.bin os-image.bin
if %errorlevel% neq 0 (
    echo [ERROR] Failed to build OS image.
    pause
    exit /b
)

REM Pad os-image.bin to exactly 1.44MB so QEMU uses correct floppy geometry (18 sectors/track)
REM Without this, QEMU may pick a smaller geometry where sectors > 9 don't exist.
powershell -Command "$f=[System.IO.File]::OpenWrite('os-image.bin'); $f.SetLength(1474560); $f.Close()"

echo.
if exist disk.img del /Q disk.img
echo Creating 16MB FAT16 virtual hard drive with ELF binaries...
python tools\make_fat16.py

%QEMU% -m 32 -drive file=os-image.bin,format=raw,index=0,if=floppy -drive file=disk.img,format=raw,index=0,if=ide -boot a -display gtk,zoom-to-fit=on -serial stdio