src/main.zig


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const debug = @import("debugcon.zig");

const ALIGN = 1 << 0;
const MEMINFO = 1 << 1;
const MAGIC = 0x1BADB002;
const FLAGS = ALIGN | MEMINFO;

const MultibootHeader = extern struct {
    magic: i32,
    flags: i32,
    checksum: i32,
};

export const multiboot align(4) linksection(".multiboot") = MultibootHeader{
    .magic = MAGIC,
    .flags = FLAGS,
    .checksum = -(MAGIC + FLAGS),
};

export var stack: [16 * 1024]u8 align(16) linksection(".bss") = undefined;

export fn _start() callconv(.Naked) noreturn {
    asm volatile (
        \\ mov %[stk], %rsp
        \\ mov %rsp, %rbp
        :
        : [stk] "{rcx}" (@intFromPtr(&stack) + @sizeOf(@TypeOf(stack))),
    );
    asm volatile ("jmp kmain");
}

export fn kmain() void {
    debug.outb(0xe9, 'H');
    debug.outb(0xe9, 'i');
    debug.outb(0xe9, '!');
    debug.outb(0xe9, '\n');

    while (true) {}
}