xref: /freebsd/lib/libc/powerpc/gen/setjmp.S (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1/*-
2 * Copyright (c) 2002 Peter Grehan.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26/*      $NetBSD: setjmp.S,v 1.3 1998/10/03 12:30:38 tsubai Exp $        */
27
28#include <machine/asm.h>
29__FBSDID("$FreeBSD$");
30
31#include <sys/syscall.h>
32
33/*
34 * C library -- setjmp, longjmp
35 *
36 *      longjmp(a,v)
37 * will generate a "return(v?v:1)" from the last call to
38 *      setjmp(a)
39 * by restoring registers from the stack.
40 * The previous signal state is restored.
41 *
42 * jmpbuf layout:
43 *     +------------+
44 *     |   unused   |
45 *     +------------+
46 *     | sig state  |
47 *     |            |
48 *     | (4 words)  |
49 *     |            |
50 *     +------------+
51 *     | saved regs |
52 *     |    ...     |
53 */
54
55ENTRY(setjmp)
56	mr	%r6,%r3
57	li	%r3,1			/* SIG_BLOCK, but doesn't matter */
58					/*            since set == NULL  */
59	li	%r4,0			/* set = NULL */
60	mr	%r5,%r6			/* &oset */
61	addi	%r5,%r5,4
62	li	%r0, SYS_sigprocmask	/*sigprocmask(SIG_BLOCK, NULL, &oset)*/
63	sc				/*assume no error       XXX */
64	mflr	%r11			/* r11 <- link reg */
65	mfcr	%r12			/* r12 <- condition reg */
66	mr	%r10,%r1		/* r10 <- stackptr */
67	mr	%r9,%r2			/*  r9 <- global ptr */
68	stmw	%r9,20(%r6)
69	li	%r3,0			/* return (0) */
70	blr
71
72	WEAK_REFERENCE(CNAME(__longjmp), longjmp)
73ENTRY(__longjmp)
74	lmw	%r9,20(%r3)		/* restore regs */
75	mr	%r6,%r4			/* save val param */
76	mtlr	%r11			/* r11 -> link reg */
77	mtcr	%r12			/* r12 -> condition reg */
78	mr	%r1,%r10		/* r10 -> stackptr */
79	mr	%r4,%r3
80	li	%r3,3			/* SIG_SETMASK */
81	addi	%r4,%r4,4		/* &set */
82	li	%r5,0			/* oset = NULL */
83	li	%r0,SYS_sigprocmask	/* sigprocmask(SIG_SET, &set, NULL) */
84	sc                              /* assume no error       XXX */
85	or.	%r3,%r6,%r6
86	bnelr
87	li	%r3,1
88	blr
89
90	.section .note.GNU-stack,"",%progbits
91