usr/src/lib/libc/mips/sys/Ovfork.s

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * %sccs.include.redist.c%
 */

#include "SYS.h"

#if defined(LIBC_SCCS) && !defined(lint)
        ASMSTR("@(#)Ovfork.s    5.1 (Berkeley) %G%")
#endif /* LIBC_SCCS and not lint */

/*
 * pid = vfork();
 *
 * v1 == 0 in parent process, v1 == 1 in child process.
 * v0 == pid of child in parent, v0 == pid of parent in child.
 */

LEAF(vfork)
        li      v0, SYS_vfork           # system call number for vfork
        syscall
        beq     a3, zero, 1f            # jump if no errors
        j       _cerror
1:
        beq     v1, zero, 2f            # parent process ?
        move    v0, zero                # return zero in child
2:
        j       ra
END(vfork)