1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: 2026 The Ebitengine Authors
3
4//go:build linux
5
6#include "textflag.h"
7#include "go_asm.h"
8#include "funcdata.h"
9
10TEXT callbackasm1(SB), NOSPLIT|NOFRAME, $0
11 NO_LOCAL_POINTERS
12
13 // Allocate stack frame: 48 + 16 + 64 + 16 = 144 bytes
14 SUB $144, R13
15
16 // Save callee-saved registers at SP+0
17 MOVW R4, 0(R13)
18 MOVW R5, 4(R13)
19 MOVW R6, 8(R13)
20 MOVW R7, 12(R13)
21 MOVW R8, 16(R13)
22 MOVW R9, 20(R13)
23 MOVW g, 24(R13)
24 MOVW R11, 28(R13)
25 MOVW R14, 32(R13)
26
27 // Save callback index (passed in R12) at SP+36
28 MOVW R12, 36(R13)
29
30 // Save integer arguments R0-R3 at SP+128 (frame[16..19])
31 MOVW R0, 128(R13)
32 MOVW R1, 132(R13)
33 MOVW R2, 136(R13)
34 MOVW R3, 140(R13)
35
36 // Save floating point registers F0-F7 at SP+64 (frame[0..15])
37 // Note: We always save these since we target hard-float ABI.
38 MOVD F0, 64(R13)
39 MOVD F1, 72(R13)
40 MOVD F2, 80(R13)
41 MOVD F3, 88(R13)
42 MOVD F4, 96(R13)
43 MOVD F5, 104(R13)
44 MOVD F6, 112(R13)
45 MOVD F7, 120(R13)
46
47 // Set up callbackArgs at SP+48
48 MOVW 36(R13), R4
49 MOVW R4, 48(R13)
50 ADD $64, R13, R4
51 MOVW R4, 52(R13)
52 MOVW $0, R4
53 MOVW R4, 56(R13)
54
55 // Call crosscall2(fn, frame, 0, ctxt)
56 MOVW ·callbackWrap_call(SB), R0
57 MOVW (R0), R0
58 ADD $48, R13, R1
59 MOVW $0, R2
60 MOVW $0, R3
61
62 BL crosscall2(SB)
63
64 // Get result
65 MOVW 56(R13), R0
66
67 // Restore float registers
68 MOVD 64(R13), F0
69 MOVD 72(R13), F1
70 MOVD 80(R13), F2
71 MOVD 88(R13), F3
72 MOVD 96(R13), F4
73 MOVD 104(R13), F5
74 MOVD 112(R13), F6
75 MOVD 120(R13), F7
76
77 // Restore callee-saved registers
78 MOVW 0(R13), R4
79 MOVW 4(R13), R5
80 MOVW 8(R13), R6
81 MOVW 12(R13), R7
82 MOVW 16(R13), R8
83 MOVW 20(R13), R9
84 MOVW 24(R13), g
85 MOVW 28(R13), R11
86 MOVW 32(R13), R14
87
88 ADD $144, R13
89 RET