minix/lib/nbsd_libc/arch/powerpc64/gen/makecontext.c
Gianluca Guida b6cbf7203b Import unmodified NetBSD libc in trunk
This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is 
split between lib/nbsd_libc and common/lib/libc.
2011-02-14 19:36:03 +00:00

82 lines
2.8 KiB
C

/* $NetBSD: makecontext.c,v 1.3 2008/04/28 20:22:57 martin Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: makecontext.c,v 1.3 2008/04/28 20:22:57 martin Exp $");
#endif
#include <inttypes.h>
#include <stddef.h>
#include <ucontext.h>
#include "extern.h"
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
void
makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
{
__greg_t *gr = ucp->uc_mcontext.__gregs;
__greg_t sp, *spp;
int i;
va_list ap;
sp = (__greg_t) ((uintptr_t)ucp->uc_stack.ss_sp
+ ucp->uc_stack.ss_size);
sp -= 2 + (argc > 8 ? argc - 8: 0); /* Make room for call frame. */
sp = (__greg_t) ((uintptr_t)sp & ~0xf);
/*
* Start executing at <func> -- when <func> completes, return to
* <_resumecontext>.
*/
gr[_REG_R1] = sp;
gr[_REG_LR] = (__greg_t)_resumecontext;
gr[_REG_PC] = (__greg_t)func; // XXX -- this is the descriptor address!
/* Wipe out stack frame backchain pointer. */
spp = (__greg_t *)sp;
*spp = 0;
/* Construct argument list. */
va_start(ap, argc);
/* Up to the first eight arguments are passed in r3-10. */
for (i = 0; i < argc && i < 8; i++)
gr[_REG_R3 + i] = va_arg(ap, long);
/* Pass remaining arguments on the stack above the backchain/lr gap. */
for (spp += 2; i < argc; i++)
*spp++ = va_arg(ap, long);
va_end(ap);
}