1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: 2026 The Ebitengine Authors
3
4//go:build !cgo && (freebsd || linux)
5
6#include "textflag.h"
7#include "go_asm.h"
8
9// These trampolines map the gcc ABI to Go ABI0 and then call into the Go equivalent functions.
10// On ARM32, Go ABI0 uses stack-based calling convention.
11// Arguments are placed on the stack starting at 4(SP) after the prologue.
12
13TEXT x_cgo_init_trampoline(SB), NOSPLIT, $8-0
14 MOVW R0, 4(R13)
15 MOVW R1, 8(R13)
16 MOVW ·x_cgo_init_call(SB), R12
17 MOVW (R12), R12
18 CALL (R12)
19 RET
20
21TEXT x_cgo_thread_start_trampoline(SB), NOSPLIT, $8-0
22 MOVW R0, 4(R13)
23 MOVW ·x_cgo_thread_start_call(SB), R12
24 MOVW (R12), R12
25 CALL (R12)
26 RET
27
28TEXT x_cgo_setenv_trampoline(SB), NOSPLIT, $8-0
29 MOVW R0, 4(R13)
30 MOVW ·x_cgo_setenv_call(SB), R12
31 MOVW (R12), R12
32 CALL (R12)
33 RET
34
35TEXT x_cgo_unsetenv_trampoline(SB), NOSPLIT, $8-0
36 MOVW R0, 4(R13)
37 MOVW ·x_cgo_unsetenv_call(SB), R12
38 MOVW (R12), R12
39 CALL (R12)
40 RET
41
42TEXT x_cgo_notify_runtime_init_done_trampoline(SB), NOSPLIT, $0-0
43 CALL ·x_cgo_notify_runtime_init_done(SB)
44 RET
45
46TEXT x_cgo_bindm_trampoline(SB), NOSPLIT, $0
47 CALL ·x_cgo_bindm(SB)
48 RET
49
50// func setg_trampoline(setg uintptr, g uintptr)
51TEXT ·setg_trampoline(SB), NOSPLIT, $0-8
52 MOVW G+4(FP), R0
53 MOVW setg+0(FP), R12
54 BL (R12)
55 RET
56
57TEXT threadentry_trampoline(SB), NOSPLIT, $104-0
58 // Save C callee-saved registers at C-to-Go boundary.
59 // See crosscall2 in asm_arm.s.
60 // ARM AAPCS callee-saved: R4-R11 (includes g=R10), D8-D15.
61 // LR is saved/restored by the Go-managed frame prologue/epilogue.
62 MOVW R0, 4(R13) // arg for threadentry_call
63
64 MOVW R4, 8(R13)
65 MOVW R5, 12(R13)
66 MOVW R6, 16(R13)
67 MOVW R7, 20(R13)
68 MOVW R8, 24(R13)
69 MOVW R9, 28(R13)
70 MOVW g, 32(R13) // R10
71 MOVW R11, 36(R13)
72
73 MOVD F8, 40(R13)
74 MOVD F9, 48(R13)
75 MOVD F10, 56(R13)
76 MOVD F11, 64(R13)
77 MOVD F12, 72(R13)
78 MOVD F13, 80(R13)
79 MOVD F14, 88(R13)
80 MOVD F15, 96(R13)
81
82 MOVW ·threadentry_call(SB), R12
83 MOVW (R12), R12
84 CALL (R12)
85
86 MOVD 40(R13), F8
87 MOVD 48(R13), F9
88 MOVD 56(R13), F10
89 MOVD 64(R13), F11
90 MOVD 72(R13), F12
91 MOVD 80(R13), F13
92 MOVD 88(R13), F14
93 MOVD 96(R13), F15
94
95 MOVW 8(R13), R4
96 MOVW 12(R13), R5
97 MOVW 16(R13), R6
98 MOVW 20(R13), R7
99 MOVW 24(R13), R8
100 MOVW 28(R13), R9
101 MOVW 32(R13), g
102 MOVW 36(R13), R11
103
104 RET
105
106TEXT ·call5(SB), NOSPLIT, $8-28
107 MOVW fn+0(FP), R12
108 MOVW a1+4(FP), R0
109 MOVW a2+8(FP), R1
110 MOVW a3+12(FP), R2
111 MOVW a4+16(FP), R3
112 MOVW a5+20(FP), R4
113
114 // Store 5th arg below SP (in local frame area)
115 MOVW R4, arg5-8(SP)
116
117 // Align SP to 8 bytes for call (required by ARM AAPCS)
118 SUB $8, R13
119 CALL (R12)
120 ADD $8, R13
121 MOVW R0, r1+24(FP)
122 RET