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section .multiboot
header_start:
dd 0xe85250d6
dd 0
dd header_end - header_start
dd 0x100000000 - (0xe85250d6 + 0 + (header_end - header_start))
; Information tag (force)
align 8
dw 1
dw 0
dd 20
dd 2
dd 4
dd 6
; Empty tag
align 8
dw 0
dw 0
dd 8
header_end:
section .start_section
dd _start
; Initialize stack
section .bss
align 16
global STACK_BOTTOM
global STACK_TOP
STACK_BOTTOM:
resb 0x4000
STACK_TOP:
section .text
global _start
extern kernel_main
_start:
mov esp, STACK_TOP
push ebx
push eax
cli
call kernel_main
cli
jmp $
global jump_userspace
jump_userspace:
cli
push ebp
mov ebp, esp
mov edx, dword [esp + 0xC]
mov esp, edx
push 0xABCDEF
mov ax, 0x23
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov eax, esp
push 0x23
push eax
pushf
; Enable interrupts
pop eax
or eax, 0x200
push eax
push 0x1B
push dword [ebp + 8]
iret
pop ebp
ret
section .end_section
global ASM_KERNEL_END
ASM_KERNEL_END:
; Kernel size detection
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