1// Copyright 2012 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5/*
6 * Apple still insists on underscore prefixes for C function names.
7 */
8#if defined(__APPLE__)
9#define EXT(s) _##s
10#else
11#define EXT(s) s
12#endif
13
14// Apple's ld64 wants 4-byte alignment for ARM code sections.
15// .align in both Apple as and GNU as treat n as aligning to 2**n bytes.
16.align	2
17
18/*
19 * void crosscall_arm1(void (*fn)(void), void (*setg_gcc)(void *g), void *g)
20 *
21 * Calling into the 5c tool chain, where all registers are caller save.
22 * Called from standard ARM EABI, where r4-r11 are callee-save, so they
23 * must be saved explicitly.
24 */
25.globl EXT(crosscall_arm1)
26EXT(crosscall_arm1):
27	push {r4, r5, r6, r7, r8, r9, r10, r11, ip, lr}
28	mov r4, r0
29	mov r5, r1
30	mov r0, r2
31
32	// Because the assembler might target an earlier revision of the ISA
33	// by default, we encode BLX as a .word.
34	.word 0xe12fff35 // blx r5 // setg(g)
35	.word 0xe12fff34 // blx r4 // fn()
36
37	pop {r4, r5, r6, r7, r8, r9, r10, r11, ip, pc}
38
39
40#ifdef __ELF__
41.section .note.GNU-stack,"",%progbits
42#endif
43