Simplified boot script.
This commit is contained in:
parent
eee9b56f86
commit
c05bcbec88
68
boot.s
68
boot.s
@ -1,58 +1,32 @@
|
||||
global start
|
||||
extern kernel_main ; Allow main() to be called from the assembly code
|
||||
extern start_ctors, end_ctors, start_dtors, end_dtors
|
||||
|
||||
MODULEALIGN equ 1<<0
|
||||
MEMINFO equ 1<<1
|
||||
FLAGS equ MODULEALIGN | MEMINFO
|
||||
MAGIC equ 0x1BADB002
|
||||
CHECKSUM equ -(MAGIC + FLAGS)
|
||||
|
||||
section .text ; Next is the Grub Multiboot Header
|
||||
; http://wiki.osdev.org/Bare_Bones_with_NASM
|
||||
MBALIGN equ 1<<0 ; align loaded modules on page boundaries
|
||||
MEMINFO equ 1<<1 ; provide memory map
|
||||
FLAGS equ MBALIGN | MEMINFO ; this is the Multiboot 'flag' field
|
||||
MAGIC equ 0x1BADB002 ; 'magic number' lets bootloader find the header
|
||||
CHECKSUM equ -(MAGIC + FLAGS) ; checksum of above, to prove we are multiboot
|
||||
|
||||
section .multiboot
|
||||
align 4
|
||||
MultiBootHeader:
|
||||
dd MAGIC
|
||||
dd FLAGS
|
||||
dd CHECKSUM
|
||||
|
||||
STACKSIZE equ 0x4000 ; 16 KiB if you're wondering
|
||||
section .bss
|
||||
align 16
|
||||
stack_bottom:
|
||||
resb 16384 ; 16 KiB
|
||||
stack_top:
|
||||
|
||||
static_ctors_loop:
|
||||
mov ebx, start_ctors
|
||||
jmp .test
|
||||
.body:
|
||||
call [ebx]
|
||||
add ebx,4
|
||||
.test:
|
||||
cmp ebx, end_ctors
|
||||
jb .body
|
||||
section .text
|
||||
global _start:function (_start.end - _start)
|
||||
_start:
|
||||
|
||||
start:
|
||||
mov esp, STACKSIZE+stack
|
||||
|
||||
push eax
|
||||
push ebx
|
||||
mov esp, stack_top
|
||||
|
||||
extern kernel_main
|
||||
call kernel_main
|
||||
|
||||
static_dtors_loop:
|
||||
mov ebx, start_dtors
|
||||
jmp .test
|
||||
.body:
|
||||
call [ebx]
|
||||
add ebx,4
|
||||
.test:
|
||||
cmp ebx, end_dtors
|
||||
jb .body
|
||||
|
||||
|
||||
cpuhalt:
|
||||
hlt
|
||||
jmp cpuhalt
|
||||
|
||||
section .bss
|
||||
align 32
|
||||
|
||||
stack:
|
||||
resb STACKSIZE
|
||||
cli
|
||||
.hang: hlt
|
||||
jmp .hang
|
||||
.end:
|
||||
|
Loading…
Reference in New Issue
Block a user