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a2c1d73b MR |
1 | /* |
2 | * Linker script macros to generate Image header fields. | |
3 | * | |
4 | * Copyright (C) 2014 ARM Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | #ifndef __ASM_IMAGE_H | |
19 | #define __ASM_IMAGE_H | |
20 | ||
21 | #ifndef LINKER_SCRIPT | |
22 | #error This file should only be included in vmlinux.lds.S | |
23 | #endif | |
24 | ||
25 | /* | |
26 | * There aren't any ELF relocations we can use to endian-swap values known only | |
27 | * at link time (e.g. the subtraction of two symbol addresses), so we must get | |
28 | * the linker to endian-swap certain values before emitting them. | |
6ad1fe5d AB |
29 | * |
30 | * Note that, in order for this to work when building the ELF64 PIE executable | |
31 | * (for KASLR), these values should not be referenced via R_AARCH64_ABS64 | |
32 | * relocations, since these are fixed up at runtime rather than at build time | |
33 | * when PIE is in effect. So we need to split them up in 32-bit high and low | |
34 | * words. | |
a2c1d73b MR |
35 | */ |
36 | #ifdef CONFIG_CPU_BIG_ENDIAN | |
6ad1fe5d AB |
37 | #define DATA_LE32(data) \ |
38 | ((((data) & 0x000000ff) << 24) | \ | |
39 | (((data) & 0x0000ff00) << 8) | \ | |
40 | (((data) & 0x00ff0000) >> 8) | \ | |
41 | (((data) & 0xff000000) >> 24)) | |
a2c1d73b | 42 | #else |
6ad1fe5d | 43 | #define DATA_LE32(data) ((data) & 0xffffffff) |
a2c1d73b MR |
44 | #endif |
45 | ||
6ad1fe5d AB |
46 | #define DEFINE_IMAGE_LE64(sym, data) \ |
47 | sym##_lo32 = DATA_LE32((data) & 0xffffffff); \ | |
48 | sym##_hi32 = DATA_LE32((data) >> 32) | |
49 | ||
a2c1d73b | 50 | #ifdef CONFIG_CPU_BIG_ENDIAN |
a7f8de16 | 51 | #define __HEAD_FLAG_BE 1 |
a2c1d73b | 52 | #else |
a7f8de16 | 53 | #define __HEAD_FLAG_BE 0 |
a2c1d73b MR |
54 | #endif |
55 | ||
a7f8de16 | 56 | #define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) |
9d372c9f | 57 | |
a7f8de16 | 58 | #define __HEAD_FLAG_PHYS_BASE 1 |
9d372c9f | 59 | |
a7f8de16 AB |
60 | #define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \ |
61 | (__HEAD_FLAG_PAGE_SIZE << 1) | \ | |
62 | (__HEAD_FLAG_PHYS_BASE << 3)) | |
a2c1d73b MR |
63 | |
64 | /* | |
65 | * These will output as part of the Image header, which should be little-endian | |
66 | * regardless of the endianness of the kernel. While constant values could be | |
67 | * endian swapped in head.S, all are done here for consistency. | |
68 | */ | |
69 | #define HEAD_SYMBOLS \ | |
6ad1fe5d AB |
70 | DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \ |
71 | DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \ | |
72 | DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS); | |
a2c1d73b | 73 | |
e8f3010f AB |
74 | #ifdef CONFIG_EFI |
75 | ||
75feee3d AB |
76 | /* |
77 | * Prevent the symbol aliases below from being emitted into the kallsyms | |
78 | * table, by forcing them to be absolute symbols (which are conveniently | |
79 | * ignored by scripts/kallsyms) rather than section relative symbols. | |
80 | * The distinction is only relevant for partial linking, and only for symbols | |
81 | * that are defined within a section declaration (which is not the case for | |
82 | * the definitions below) so the resulting values will be identical. | |
83 | */ | |
84 | #define KALLSYMS_HIDE(sym) ABSOLUTE(sym) | |
85 | ||
e8f3010f AB |
86 | /* |
87 | * The EFI stub has its own symbol namespace prefixed by __efistub_, to | |
88 | * isolate it from the kernel proper. The following symbols are legally | |
89 | * accessed by the stub, so provide some aliases to make them accessible. | |
90 | * Only include data symbols here, or text symbols of functions that are | |
91 | * guaranteed to be safe when executed at another offset than they were | |
92 | * linked at. The routines below are all implemented in assembler in a | |
93 | * position independent manner | |
94 | */ | |
75feee3d AB |
95 | __efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp); |
96 | __efistub_memchr = KALLSYMS_HIDE(__pi_memchr); | |
97 | __efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy); | |
98 | __efistub_memmove = KALLSYMS_HIDE(__pi_memmove); | |
99 | __efistub_memset = KALLSYMS_HIDE(__pi_memset); | |
100 | __efistub_strlen = KALLSYMS_HIDE(__pi_strlen); | |
7f4e3462 | 101 | __efistub_strnlen = KALLSYMS_HIDE(__pi_strnlen); |
75feee3d AB |
102 | __efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp); |
103 | __efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp); | |
104 | __efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area); | |
e8f3010f | 105 | |
39d114dd | 106 | #ifdef CONFIG_KASAN |
75feee3d AB |
107 | __efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy); |
108 | __efistub___memmove = KALLSYMS_HIDE(__pi_memmove); | |
109 | __efistub___memset = KALLSYMS_HIDE(__pi_memset); | |
39d114dd AR |
110 | #endif |
111 | ||
75feee3d AB |
112 | __efistub__text = KALLSYMS_HIDE(_text); |
113 | __efistub__end = KALLSYMS_HIDE(_end); | |
114 | __efistub__edata = KALLSYMS_HIDE(_edata); | |
e8f3010f AB |
115 | |
116 | #endif | |
117 | ||
a2c1d73b | 118 | #endif /* __ASM_IMAGE_H */ |