xref: /minix3/lib/libc/arch/or1k/sys/fork.S (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc/*	$NetBSD: fork.S,v 1.1 2014/09/03 19:34:26 matt Exp $	*/
2*0a6a1f1dSLionel Sambuc
3*0a6a1f1dSLionel Sambuc/*
4*0a6a1f1dSLionel Sambuc * pid = fork();
5*0a6a1f1dSLionel Sambuc *
6*0a6a1f1dSLionel Sambuc * r12 == 0 in parent process, 1 in child process.
7*0a6a1f1dSLionel Sambuc * r11 == pid of child in parent, pid of parent in child.
8*0a6a1f1dSLionel Sambuc */
9*0a6a1f1dSLionel Sambuc
10*0a6a1f1dSLionel Sambuc#include "SYS.h"
11*0a6a1f1dSLionel Sambuc
12*0a6a1f1dSLionel Sambuc_SYSCALL(__fork,fork)
13*0a6a1f1dSLionel Sambuc	l.addi	r12,r12,-1	# from 1 to 0 in child, 0 to -1 in parent
14*0a6a1f1dSLionel Sambuc	l.and	r11,r11,r12	# return 0 in child, pid in parent
15*0a6a1f1dSLionel Sambuc	l.jr	lr
16*0a6a1f1dSLionel Sambuc	l.nop
17*0a6a1f1dSLionel SambucEND(__fork)
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