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)
26 EXT(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
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