53 lines
1.6 KiB
ArmAsm
53 lines
1.6 KiB
ArmAsm
/* $NetBSD: Ovfork.S,v 1.4 1998/12/02 19:29:57 thorpej Exp $ */
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/*
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* Copyright (c) 1992 Helsinki University of Technology
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* All Rights Reserved.
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* HELSINKI UNIVERSITY OF TECHNOLOGY ALLOWS FREE USE OF THIS SOFTWARE IN
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* ITS "AS IS" CONDITION. HELSINKI UNIVERSITY OF TECHNOLOGY DISCLAIMS ANY
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* LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE
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* USE OF THIS SOFTWARE.
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*/
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/*
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* HISTORY
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* 29-Apr-92 Johannes Helander (jvh) at Helsinki University of Technology
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* Created.
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*/
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#include "SYS.h"
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#if defined(LIBC_SCCS)
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RCSID("$NetBSD: Ovfork.S,v 1.4 1998/12/02 19:29:57 thorpej Exp $")
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#endif
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WARN_REFERENCES(vfork, \
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"warning: reference to compatibility vfork(); include <unistd.h> for correct reference")
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/*
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* r0 = pid of child in parent / pid of parent in child
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* r1 = 0 in parent, 1 in child
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*
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* trickery here, due to keith sklower, uses ret to clear the stack,
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* and then returns with a jump indirect, since only one person can return
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* with a ret off this stack... we do the ret before we vfork!
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* (This is not really true for NetBSD. NetBSD's vfork creates a new
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* vm context for the child).
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*/
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ENTRY(vfork)
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movd tos,r2
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SYSTRAP(vfork)
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bcc 0f
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movd r2,tos
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br _ASM_LABEL(cerror)
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0: cmpqd 0,r1
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beq 0f
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movqd 0,r0
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0: jump 0(r2)
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