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const char* greeting_msg = "Hello, world!";

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#include <stddef.h>
#include <stdint.h>

uint8_t* video;

void cls(){
    video = 0xb8000;
    for(size_t i = 0; i < 25*80; ++i){
        *(video++) = ' ';
        *(video++) = 0x1F;
    }
    video = 0xb8000;
}

void write(const char* data){
    for(size_t i = 0; data[i] != '\0'; ++i){
        *(video++) = data[i];
        *(video++) = 0x1F;
    }
}

void kmain(void){
    cls();
    const char* greeting_msg = "Hello, world!";
    write(greeting_msg);
}

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osname = AltOS

init:
	rm -rf $(osname).iso
	rm -rf obj
	rm -rf bin
	rm -rf iso
	mkdir obj
	mkdir bin
	mkdir iso
	mkdir iso/boot
	mkdir iso/boot/grub
compile:
	x86_64-elf-gcc src/c/kmain.c -o obj/kmain.o -std=gnu99 -ffreestanding -O2 -Wall -Wextra -nostdlib
assembly:
	nasm -f elf64 src/asm/multiboot_header.asm -o obj/multiboot_header.o
	nasm -f elf64 src/asm/boot.asm -o obj/boot.o
	nasm -f elf64 src/asm/long.asm -o obj/long.o
link:
	x86_64-elf-ld -n -o bin/kernel.bin -T src/ld/linker.ld obj/kmain.o obj/multiboot_header.o obj/boot.o obj/long.o 

grubprepare:
	cp bin/kernel.bin iso/boot
	echo 'set timeout=0' >> iso/boot/grub/grub.cfg
	echo 'set default=0' >> iso/boot/grub/grub.cfg
	echo 'menuentry "AltOS" {' >> iso/boot/grub/grub.cfg
	echo '	multiboot2 /boot/kernel.bin' >> iso/boot/grub/grub.cfg
	echo '	boot'  >> iso/boot/grub/grub.cfg
	echo '}' >> iso/boot/grub/grub.cfg

image:
	grub-mkrescue -o $(osname).iso iso

vm:
	qemu-system-x86_64 -cdrom $(osname).iso

run: init compile assembly link grubprepare image vm

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x86_64-elf-gcc -c src/c/kmain.c src/c/vgacolor.c -o obj/kmain.o -std=gnu99 -ffreestanding -O2 -Wall -Wextra -nostdlib
x86_64-elf-gcc: fatal error: cannot specify -o with -c, -S or -E with multiple files
compilation terminated.