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Diffstat (limited to 'src/runtime/cgo/gcc_arm.S')
-rw-r--r-- | src/runtime/cgo/gcc_arm.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/runtime/cgo/gcc_arm.S b/src/runtime/cgo/gcc_arm.S new file mode 100644 index 0000000..6e8c14a --- /dev/null +++ b/src/runtime/cgo/gcc_arm.S @@ -0,0 +1,44 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +.file "gcc_arm.S" + +/* + * Apple still insists on underscore prefixes for C function names. + */ +#if defined(__APPLE__) +#define EXT(s) _##s +#else +#define EXT(s) s +#endif + +// Apple's ld64 wants 4-byte alignment for ARM code sections. +// .align in both Apple as and GNU as treat n as aligning to 2**n bytes. +.align 2 + +/* + * void crosscall_arm1(void (*fn)(void), void (*setg_gcc)(void *g), void *g) + * + * Calling into the 5c tool chain, where all registers are caller save. + * Called from standard ARM EABI, where r4-r11 are callee-save, so they + * must be saved explicitly. + */ +.globl EXT(crosscall_arm1) +EXT(crosscall_arm1): + push {r4, r5, r6, r7, r8, r9, r10, r11, ip, lr} + mov r4, r0 + mov r5, r1 + mov r0, r2 + + // Because the assembler might target an earlier revision of the ISA + // by default, we encode BLX as a .word. + .word 0xe12fff35 // blx r5 // setg(g) + .word 0xe12fff34 // blx r4 // fn() + + pop {r4, r5, r6, r7, r8, r9, r10, r11, ip, pc} + + +#ifdef __ELF__ +.section .note.GNU-stack,"",%progbits +#endif |