xref: /freebsd/lib/libc/powerpc/gen/_ctx_start.S (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1/*
2 * Copyright (c) 2004 Suleiman Souhlal
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
27 #include <machine/asm.h>
28
29 __FBSDID("$FreeBSD$");
30
31	.globl  CNAME(_ctx_done)
32	.globl  CNAME(abort)
33
34 ENTRY(_ctx_start)
35	mtlr	%r14
36	blrl			/* branch to start function */
37	mr	%r3,%r15	/* pass pointer to ucontext as argument */
38	bl	CNAME(_ctx_done) /* branch to ctxt completion func */
39
40	/*
41	 * we should never return from the
42	 * above branch.
43	 */
44	/* Don't bother saving off %r30, we're already in a bad state. */
45	bcl	20,31,1f
461:	mflr	%r30
47	mr	%r3,%r30		# save for _DYNAMIC
48	addis	%r30,%r30,_GLOBAL_OFFSET_TABLE_-1b@ha
49	addi	%r30,%r30,_GLOBAL_OFFSET_TABLE_-1b@l
50	bl	PIC_PLT(CNAME(abort))	/* abort */
51 END(_ctx_start)
52
53	.section .note.GNU-stack,"",%progbits
54