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;> 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 24
; 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
push ebx
push eax
extern cmain
call cmain
cli
jmp $
.end:
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