memcpy((char *)gdtp.base, (char *)gdt, gdtp.limit+1);

# Default make target
all: os.img


# Build the os image
os.img: boot.bin kernel.bin
        cat boot.bin kernel.bin > os.img

# Build the kernel binary
kernel.bin: kernel_entry.o kernel.o  scrn.o gdt.o
        ld -nostdlib --file-alignment 0 --section-alignment 32 -o kernel.tmp -Ttext 0x1000 kernel_entry.o kernel.o  scrn.o gdt.o
        objcopy -O binary  kernel.tmp kernel.bin

# Build the kernel object file
kernel.o: kernel.c
        gcc -mno-ms-bitfields -ffreestanding -c kernel.c -o kernel.o

# Build the scrn object file
scrn.o: scrn.c
        gcc -mno-ms-bitfields -ffreestanding -c scrn.c -o scrn.o

# Build the gdt object file
gdt.o: gdt.c
        gcc -mno-ms-bitfields -ffreestanding -c gdt.c -o gdt.o


# Build the kernel entry object file
kernel_entry.o: kernel_entry.asm
        nasm kernel_entry.asm -f win32 -o kernel_entry.o


# Build the boot binary
boot.bin: boot.asm
        nasm -f bin -o boot.bin boot.asm

clean:
        rm -f *.o *.tmp *.bin

[bits 32]
section .text
extern _kmain

call _kmain
jmp $

global _load_gdtr
extern _gdtp
_load_gdtr:
    lgdt [_gdtp]
    mov ax, 0x10
    mov ds, ax
    mov es, ax
    mov fs, ax
    mov gs, ax
    mov ss, ax
    jmp 0x08:next
next:
    ret