1 /* LoongArch ABI-specified defaults for DWARF CFI.
2 Copyright (C) 2023 OpenAnolis community LoongArch SIG.
3 Copyright (C) 2023 Loongson Technology Corporation Limted.
4 This file is part of elfutils.
5
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
8
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
12
13 or
14
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
18
19 or both in parallel, as here.
20
21 elfutils is distributed in the hope that it will be useful, but
22 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
25
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
29
30 #ifdef HAVE_CONFIG_H
31 # include <config.h>
32 #endif
33
34 #include <dwarf.h>
35
36 #define BACKEND loongarch_
37 #include "libebl_CPU.h"
38
39 /* LoongArch ELF ABI specification:
40 https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html#_register_convention
41 */
42 int
loongarch_abi_cfi(Ebl * ebl,Dwarf_CIE * abi_info)43 loongarch_abi_cfi (Ebl *ebl __attribute__ ((unused)), Dwarf_CIE *abi_info)
44 {
45 static const uint8_t abi_cfi[] =
46 {
47 /* The initial Canonical Frame Address is the value of the
48 Stack Pointer ($r3) as setup in the previous frame. */
49 DW_CFA_def_cfa, ULEB128_7 (3), ULEB128_7 (0),
50
51 /* The Stack Pointer ($r3) is restored from CFA address by default. */
52 DW_CFA_val_offset, ULEB128_7 (3), ULEB128_7 (0),
53
54 #define SV(n) DW_CFA_same_value, ULEB128_7 (n)
55 /* The return address register contains the return address setup by
56 caller. */
57 SV (1),
58
59 /* Callee-saved registers $s0-$s7. */
60 SV (23), SV (24), SV (25), SV (26), SV (27), SV (28),
61 SV (29), SV (30), SV (31),
62
63 /* The Frame Pointer ($fp, $r22) */
64 SV(22),
65
66 /* Callee-saved registers $fs0-$fs7. */
67 SV (56), SV (57), SV (58), SV (59), SV (60), SV (61),
68 SV (62), SV (63),
69 #undef SV
70
71 /* XXX Note: registers intentionally unused by the program,
72 for example as a consequence of the procedure call standard
73 should be initialized as if by DW_CFA_same_value. */
74 };
75
76 abi_info->initial_instructions = abi_cfi;
77 abi_info->initial_instructions_end = &abi_cfi[sizeof abi_cfi];
78 abi_info->data_alignment_factor = -4;
79
80 abi_info->return_address_register = 1; /* ra. */
81
82 return 0;
83 }
84