;> The Multiboot header must be contained completely within the first 8192 bytes of the OS 
;> image, and must be longword (32-bit) aligned.
MULTIBOOT_ALIGN_TO_PAGE:   equ 1 << 0
MULTIBOOT_MEMORY_DESCRIBE: equ 1 << 1
MULTIBOOT_VIDEO_MODE:      equ 1 << 2
MULTIBOOT_MAGIC:           equ 0x1BADB002
MULTIBOOT_FLAGS:           equ (MULTIBOOT_ALIGN_TO_PAGE | MULTIBOOT_MEMORY_DESCRIBE | MULTIBOOT_VIDEO_MODE)
MULTIBOOT_CHECKSUM:        equ -(MULTIBOOT_MAGIC + MULTIBOOT_FLAGS)
MULTIBOOT_VIDEO_TYPE:      equ 0
MULTIBOOT_GODS_WIDTH:      equ 640
MULTIBOOT_GODS_HEIGHT:     equ 480
MULTIBOOT_VIDEO_BPP:       equ 16

; We don't set flags[16] because we assemble to ELF32 so header_addr, etc is useless to us
; (at least at the moment).
UNUSED_BYTES_COUNT: equ 5*4
section .multiboot_header:
; I guess multiboot 2 requires a length field and we might migrate to that in the future.
multiboot_header_start:
align 4
    dd MULTIBOOT_MAGIC
    dd MULTIBOOT_FLAGS
    dd MULTIBOOT_CHECKSUM
    times UNUSED_BYTES_COUNT db 0
    dd MULTIBOOT_VIDEO_TYPE
    dd MULTIBOOT_GODS_WIDTH
    dd MULTIBOOT_GODS_HEIGHT
    dd MULTIBOOT_VIDEO_BPP
multiboot_header_end:

STACK_SIZE: equ (1 << 14)
section .bss
align 16
stack_bottom: ; ("haha bottom" somewhere in there??)
    resb STACK_SIZE
stack_top:

section .text
global _start:function (_start.end - _start)
_start:
    mov esp, stack_top
    extern cmain
    call cmain
    cli

jmp $

.end: