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Diffstat (limited to 'src/runtime/cgo/asm_arm64.s')
| -rw-r--r-- | src/runtime/cgo/asm_arm64.s | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/runtime/cgo/asm_arm64.s b/src/runtime/cgo/asm_arm64.s new file mode 100644 index 0000000..5492dc1 --- /dev/null +++ b/src/runtime/cgo/asm_arm64.s @@ -0,0 +1,50 @@ +// Copyright 2015 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. + +#include "textflag.h" +#include "abi_arm64.h" + +// Set the x_crosscall2_ptr C function pointer variable point to crosscall2. +// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2 +// Use a local trampoline, to avoid taking the address of a dynamically exported +// function. +TEXT ·set_crosscall2(SB),NOSPLIT,$0-0 + MOVD _crosscall2_ptr(SB), R1 + MOVD $crosscall2_trampoline<>(SB), R2 + MOVD R2, (R1) + RET + +TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0 + JMP crosscall2(SB) + +// Called by C code generated by cmd/cgo. +// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr) +// Saves C callee-saved registers and calls cgocallback with three arguments. +// fn is the PC of a func(a unsafe.Pointer) function. +TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0 + /* + * We still need to save all callee save register as before, and then + * push 3 args for fn (R0, R1, R3), skipping R2. + * Also note that at procedure entry in gc world, 8(RSP) will be the + * first arg. + */ + SUB $(8*24), RSP + STP (R0, R1), (8*1)(RSP) + MOVD R3, (8*3)(RSP) + + SAVE_R19_TO_R28(8*4) + SAVE_F8_TO_F15(8*14) + STP (R29, R30), (8*22)(RSP) + + + // Initialize Go ABI environment + BL runtime·load_g(SB) + BL runtime·cgocallback(SB) + + RESTORE_R19_TO_R28(8*4) + RESTORE_F8_TO_F15(8*14) + LDP (8*22)(RSP), (R29, R30) + + ADD $(8*24), RSP + RET |