43 lines
929 B
NASM
43 lines
929 B
NASM
; since we have no stack we have to create one for the OS
|
|
|
|
global loader
|
|
MAGIC_NUMBER equ 0x1BADB002
|
|
FLAGS equ 0x0
|
|
CHECKSUM equ -MAGIC_NUMBER
|
|
|
|
; example stuff
|
|
A equ 3
|
|
B equ 2
|
|
C equ 1
|
|
|
|
; size in bytes
|
|
KERNEL_STACK_SIZE equ 4096
|
|
|
|
; external labels(cdecl) calling convention
|
|
extern colors
|
|
|
|
section .bss
|
|
align 4 ; aligning to bytes for x86(32-bit) reasons
|
|
; because this is the first thing we actually do (virual)address 0x00000000 will
|
|
; contain 4KB of memory for our stack
|
|
kernel_stack:
|
|
resb KERNEL_STACK_SIZE ; reserver bytes instruction
|
|
; point to what will be bottom of stack
|
|
; which will grow down towards (virtual)address 0x00000000
|
|
mov esp, kernel_stack + KERNEL_STACK_SIZE
|
|
|
|
section .text
|
|
; align all instructions to 4 byte boundary by the x86 instruction set law
|
|
align 4
|
|
; dropping our magic and other things into memory
|
|
dd MAGIC_NUMBER
|
|
dd FLAGS
|
|
dd CHECKSUM
|
|
|
|
loader:
|
|
; pls
|
|
call colors
|
|
|
|
.loop:
|
|
jmp .loop
|