1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: 2025 The Ebitengine Authors
3
4//go:build linux
5
6#include "textflag.h"
7#include "go_asm.h"
8#include "funcdata.h"
9
10#define STACK_SIZE 64
11#define PTR_ADDRESS (STACK_SIZE - 8)
12
13// syscall15X calls a function in libc on behalf of the syscall package.
14// syscall15X takes a pointer to a struct like:
15// struct {
16// fn uintptr
17// a1 uintptr
18// a2 uintptr
19// a3 uintptr
20// a4 uintptr
21// a5 uintptr
22// a6 uintptr
23// a7 uintptr
24// a8 uintptr
25// a9 uintptr
26// a10 uintptr
27// a11 uintptr
28// a12 uintptr
29// a13 uintptr
30// a14 uintptr
31// a15 uintptr
32// r1 uintptr
33// r2 uintptr
34// err uintptr
35// }
36// syscall15X must be called on the g0 stack with the
37// C calling convention (use libcCall).
38GLOBL ·syscall15XABI0(SB), NOPTR|RODATA, $8
39DATA ·syscall15XABI0(SB)/8, $syscall15X(SB)
40TEXT syscall15X(SB), NOSPLIT, $0
41 // push structure pointer
42 SUBV $STACK_SIZE, R3
43 MOVV R4, PTR_ADDRESS(R3)
44 MOVV R4, R13
45
46 MOVD syscall15Args_f1(R13), F0 // f1
47 MOVD syscall15Args_f2(R13), F1 // f2
48 MOVD syscall15Args_f3(R13), F2 // f3
49 MOVD syscall15Args_f4(R13), F3 // f4
50 MOVD syscall15Args_f5(R13), F4 // f5
51 MOVD syscall15Args_f6(R13), F5 // f6
52 MOVD syscall15Args_f7(R13), F6 // f7
53 MOVD syscall15Args_f8(R13), F7 // f8
54
55 MOVV syscall15Args_a1(R13), R4 // a1
56 MOVV syscall15Args_a2(R13), R5 // a2
57 MOVV syscall15Args_a3(R13), R6 // a3
58 MOVV syscall15Args_a4(R13), R7 // a4
59 MOVV syscall15Args_a5(R13), R8 // a5
60 MOVV syscall15Args_a6(R13), R9 // a6
61 MOVV syscall15Args_a7(R13), R10 // a7
62 MOVV syscall15Args_a8(R13), R11 // a8
63
64 // push a9-a15 onto stack
65 MOVV syscall15Args_a9(R13), R12
66 MOVV R12, 0(R3)
67 MOVV syscall15Args_a10(R13), R12
68 MOVV R12, 8(R3)
69 MOVV syscall15Args_a11(R13), R12
70 MOVV R12, 16(R3)
71 MOVV syscall15Args_a12(R13), R12
72 MOVV R12, 24(R3)
73 MOVV syscall15Args_a13(R13), R12
74 MOVV R12, 32(R3)
75 MOVV syscall15Args_a14(R13), R12
76 MOVV R12, 40(R3)
77 MOVV syscall15Args_a15(R13), R12
78 MOVV R12, 48(R3)
79
80 MOVV syscall15Args_fn(R13), R12
81 JAL (R12)
82
83 // pop structure pointer
84 MOVV PTR_ADDRESS(R3), R13
85 ADDV $STACK_SIZE, R3
86
87 // save R4, R5
88 MOVV R4, syscall15Args_a1(R13)
89 MOVV R5, syscall15Args_a2(R13)
90
91 // save f0-f3
92 MOVD F0, syscall15Args_f1(R13)
93 MOVD F1, syscall15Args_f2(R13)
94 MOVD F2, syscall15Args_f3(R13)
95 MOVD F3, syscall15Args_f4(R13)
96 RET