retroforth/vm/nga-c-no-libc/fbsd.s

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; ___ ___ _____ ___ ___ __ ___ ___ ___ ___
; | _ \ __|_ _| _ \/ _ \ / / | __| _ ___ ___| _ ) __| \
; | / _| | | | / (_) | / / | _| '_/ -_) -_) _ \__ \ |) |
; |_|_\___| |_| |_|_\\___/ /_/ |_||_| \___\___|___/___/___/
;
; This is the minimal startup + I/O functionality needed to run
; RETRO on a FreeBSD x86 system.
; =============================================================
bits 32
section .text
global putchar
global getchar
global _start
extern main
align 4
_start:
call main
jmp $
align 4
putchar:
mov eax, [esp+4]
mov [buf], eax
push dword 1
push dword buf
push dword 1
mov eax, 4
call kernel
add esp, 12
ret
align 4
getchar:
push dword 1
push dword buf
push dword 0
mov eax, 3
call kernel
add esp, 12
mov eax, 0
mov eax, [buf]
ret
align 4
kernel:
int 80h
ret
section .data
buf:
dd 0
dd 0
dd 0
dd 0