1// Copyright 2020 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#include "textflag.h" 6 7// Set the x_crosscall2_ptr C function pointer variable point to crosscall2. 8// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2 9// Use a local trampoline, to avoid taking the address of a dynamically exported 10// function. 11TEXT ·set_crosscall2(SB),NOSPLIT,$0-0 12 MOV _crosscall2_ptr(SB), X7 13 MOV $crosscall2_trampoline<>(SB), X8 14 MOV X8, (X7) 15 RET 16 17TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0 18 JMP crosscall2(SB) 19 20// Called by C code generated by cmd/cgo. 21// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr) 22// Saves C callee-saved registers and calls cgocallback with three arguments. 23// fn is the PC of a func(a unsafe.Pointer) function. 24TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0 25 /* 26 * Push arguments for fn (X10, X11, X13), along with all callee-save 27 * registers. Note that at procedure entry the first argument is at 28 * 8(X2). 29 */ 30 ADD $(-8*29), X2 31 MOV X10, (8*1)(X2) // fn unsafe.Pointer 32 MOV X11, (8*2)(X2) // a unsafe.Pointer 33 MOV X13, (8*3)(X2) // ctxt uintptr 34 MOV X8, (8*4)(X2) 35 MOV X9, (8*5)(X2) 36 MOV X18, (8*6)(X2) 37 MOV X19, (8*7)(X2) 38 MOV X20, (8*8)(X2) 39 MOV X21, (8*9)(X2) 40 MOV X22, (8*10)(X2) 41 MOV X23, (8*11)(X2) 42 MOV X24, (8*12)(X2) 43 MOV X25, (8*13)(X2) 44 MOV X26, (8*14)(X2) 45 MOV g, (8*15)(X2) 46 MOV X1, (8*16)(X2) 47 MOVD F8, (8*17)(X2) 48 MOVD F9, (8*18)(X2) 49 MOVD F18, (8*19)(X2) 50 MOVD F19, (8*20)(X2) 51 MOVD F20, (8*21)(X2) 52 MOVD F21, (8*22)(X2) 53 MOVD F22, (8*23)(X2) 54 MOVD F23, (8*24)(X2) 55 MOVD F24, (8*25)(X2) 56 MOVD F25, (8*26)(X2) 57 MOVD F26, (8*27)(X2) 58 MOVD F27, (8*28)(X2) 59 60 // Initialize Go ABI environment 61 CALL runtime·load_g(SB) 62 CALL runtime·cgocallback(SB) 63 64 MOV (8*4)(X2), X8 65 MOV (8*5)(X2), X9 66 MOV (8*6)(X2), X18 67 MOV (8*7)(X2), X19 68 MOV (8*8)(X2), X20 69 MOV (8*9)(X2), X21 70 MOV (8*10)(X2), X22 71 MOV (8*11)(X2), X23 72 MOV (8*12)(X2), X24 73 MOV (8*13)(X2), X25 74 MOV (8*14)(X2), X26 75 MOV (8*15)(X2), g 76 MOV (8*16)(X2), X1 77 MOVD (8*17)(X2), F8 78 MOVD (8*18)(X2), F9 79 MOVD (8*19)(X2), F18 80 MOVD (8*20)(X2), F19 81 MOVD (8*21)(X2), F20 82 MOVD (8*22)(X2), F21 83 MOVD (8*23)(X2), F22 84 MOVD (8*24)(X2), F23 85 MOVD (8*25)(X2), F24 86 MOVD (8*26)(X2), F25 87 MOVD (8*27)(X2), F26 88 MOVD (8*28)(X2), F27 89 ADD $(8*29), X2 90 91 RET 92