vulcanos/kernel/cpu/kernel_loader.asm
2021-01-02 17:49:15 +01:00

44 lines
1.2 KiB
NASM

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; vulcanOS Kernel ;
; Developed by Marco 'icebit' Cetica ;
; (c) 2019-2021 ;
; Released under GPLv3 ;
; https://github.com/ice-bit/iceOS ;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
[BITS 32] ; We should be in protected mode
section .multiboot
head_s:
dd 0xE85250D6 ; Multiboot header magic number
dd 0 ; Protected mode flag
dd head_e - head_s ; Header length
dd 0x100000000 - (0xE85250D6 + 0 + (head_e - head_s)) ; Checksum of above
; Other flags
dw 0 ; type
dw 0 ; flags
dd 0 ; size
head_e:
GLOBAL kernel_loader
EXTERN kernel_main
section .text
kernel_loader:
mov esp, kernel_stack + KERNEL_STACK_SZ ; Define stack pointer
push ebx ; Set multiboot header
call kernel_main ; Jump into kernel's main function
.loop:
jmp .loop ; If the kernel returns, go into an infinite loop.
; This will prevent the CPU to run non-kernel instructions
; from the memory
KERNEL_STACK_SZ equ 4096 ; Stack size(4KiB)
section .bss
align 4
kernel_stack:
resb KERNEL_STACK_SZ ; Reserve 4 KiB