1 /* arm ABI-specified defaults for DWARF CFI.
2 Copyright (C) 2013 Red Hat, Inc.
3 This file is part of elfutils.
4
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
7
8 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
11
12 or
13
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
17
18 or both in parallel, as here.
19
20 elfutils is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
24
25 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
28
29 #ifdef HAVE_CONFIG_H
30 # include <config.h>
31 #endif
32
33 #include <dwarf.h>
34
35 #define BACKEND arm_
36 #include "libebl_CPU.h"
37
38
39 /* ABI-specified state of DWARF CFI based on:
40
41 "DWARF for the ARM Architecture ABI r2.09"
42 http://infocenter.arm.com/help/topic/com.arm.doc.ihi0040b/IHI0040B_aadwarf.pdf
43
44 "Procedure Call Standard for the ARM Architecture ABI r2.09"
45 http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042e/IHI0042E_aapcs.pdf
46 */
47
48 int
arm_abi_cfi(Ebl * ebl,Dwarf_CIE * abi_info)49 arm_abi_cfi (Ebl *ebl __attribute__ ((unused)), Dwarf_CIE *abi_info)
50 {
51 static const uint8_t abi_cfi[] =
52 {
53 /* The initial Canonical Frame Address is the value of the
54 Stack Pointer (r13) as setup in the previous frame. */
55 DW_CFA_def_cfa, ULEB128_7 (13), ULEB128_7 (0),
56
57 /* The Stack Pointer (r13) is restored from CFA address by default. */
58 DW_CFA_val_offset, ULEB128_7 (13), ULEB128_7 (0),
59
60 #define SV(n) DW_CFA_same_value, ULEB128_7 (n)
61 /* Callee-saved regs r4-r8, r10, r11. */
62 SV (4), SV (5), SV (6), SV (7), SV (8), SV (10), SV (11),
63
64 /* The link register contains the return address setup by caller. */
65 SV (14),
66 DW_CFA_register, ULEB128_7 (15), ULEB128_7 (14), /* pc = lr */
67 #undef SV
68
69 /* VFP S16-S31/D8-D15/Q4-Q7 are callee saved.
70 And uleb128 encoded with two bytes. */
71 #define ULEB128_8_2(x) ((x & 0x7f) | 0x80), 0x02
72 #define SV(n) DW_CFA_same_value, ULEB128_8_2 (n)
73 SV (264), SV (265), SV (266), SV (267),
74 SV (268), SV (269), SV (270), SV (271),
75
76 /* XXX Note: registers intentionally unused by the program,
77 for example as a consequence of the procedure call standard
78 should be initialized as if by DW_CFA_same_value. */
79 };
80 #undef ULEB128_8_2
81 #undef SV
82
83 abi_info->initial_instructions = abi_cfi;
84 abi_info->initial_instructions_end = &abi_cfi[sizeof abi_cfi];
85 abi_info->data_alignment_factor = 4;
86
87 abi_info->return_address_register = 15; /* pc. */
88
89 return 0;
90 }
91