| 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. |
| 29 | */ |
| 30 | #ifdef CONFIG_CPU_BIG_ENDIAN |
| 31 | #define DATA_LE64(data) \ |
| 32 | ((((data) & 0x00000000000000ff) << 56) | \ |
| 33 | (((data) & 0x000000000000ff00) << 40) | \ |
| 34 | (((data) & 0x0000000000ff0000) << 24) | \ |
| 35 | (((data) & 0x00000000ff000000) << 8) | \ |
| 36 | (((data) & 0x000000ff00000000) >> 8) | \ |
| 37 | (((data) & 0x0000ff0000000000) >> 24) | \ |
| 38 | (((data) & 0x00ff000000000000) >> 40) | \ |
| 39 | (((data) & 0xff00000000000000) >> 56)) |
| 40 | #else |
| 41 | #define DATA_LE64(data) ((data) & 0xffffffffffffffff) |
| 42 | #endif |
| 43 | |
| 44 | #ifdef CONFIG_CPU_BIG_ENDIAN |
| 45 | #define __HEAD_FLAG_BE 1 |
| 46 | #else |
| 47 | #define __HEAD_FLAG_BE 0 |
| 48 | #endif |
| 49 | |
| 50 | #define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) |
| 51 | |
| 52 | #define __HEAD_FLAG_PHYS_BASE 1 |
| 53 | |
| 54 | #define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \ |
| 55 | (__HEAD_FLAG_PAGE_SIZE << 1) | \ |
| 56 | (__HEAD_FLAG_PHYS_BASE << 3)) |
| 57 | |
| 58 | /* |
| 59 | * These will output as part of the Image header, which should be little-endian |
| 60 | * regardless of the endianness of the kernel. While constant values could be |
| 61 | * endian swapped in head.S, all are done here for consistency. |
| 62 | */ |
| 63 | #define HEAD_SYMBOLS \ |
| 64 | _kernel_size_le = DATA_LE64(_end - _text); \ |
| 65 | _kernel_offset_le = DATA_LE64(TEXT_OFFSET); \ |
| 66 | _kernel_flags_le = DATA_LE64(__HEAD_FLAGS); |
| 67 | |
| 68 | #ifdef CONFIG_EFI |
| 69 | |
| 70 | /* |
| 71 | * Prevent the symbol aliases below from being emitted into the kallsyms |
| 72 | * table, by forcing them to be absolute symbols (which are conveniently |
| 73 | * ignored by scripts/kallsyms) rather than section relative symbols. |
| 74 | * The distinction is only relevant for partial linking, and only for symbols |
| 75 | * that are defined within a section declaration (which is not the case for |
| 76 | * the definitions below) so the resulting values will be identical. |
| 77 | */ |
| 78 | #define KALLSYMS_HIDE(sym) ABSOLUTE(sym) |
| 79 | |
| 80 | /* |
| 81 | * The EFI stub has its own symbol namespace prefixed by __efistub_, to |
| 82 | * isolate it from the kernel proper. The following symbols are legally |
| 83 | * accessed by the stub, so provide some aliases to make them accessible. |
| 84 | * Only include data symbols here, or text symbols of functions that are |
| 85 | * guaranteed to be safe when executed at another offset than they were |
| 86 | * linked at. The routines below are all implemented in assembler in a |
| 87 | * position independent manner |
| 88 | */ |
| 89 | __efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp); |
| 90 | __efistub_memchr = KALLSYMS_HIDE(__pi_memchr); |
| 91 | __efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy); |
| 92 | __efistub_memmove = KALLSYMS_HIDE(__pi_memmove); |
| 93 | __efistub_memset = KALLSYMS_HIDE(__pi_memset); |
| 94 | __efistub_strlen = KALLSYMS_HIDE(__pi_strlen); |
| 95 | __efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp); |
| 96 | __efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp); |
| 97 | __efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area); |
| 98 | |
| 99 | #ifdef CONFIG_KASAN |
| 100 | __efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy); |
| 101 | __efistub___memmove = KALLSYMS_HIDE(__pi_memmove); |
| 102 | __efistub___memset = KALLSYMS_HIDE(__pi_memset); |
| 103 | #endif |
| 104 | |
| 105 | __efistub__text = KALLSYMS_HIDE(_text); |
| 106 | __efistub__end = KALLSYMS_HIDE(_end); |
| 107 | __efistub__edata = KALLSYMS_HIDE(_edata); |
| 108 | |
| 109 | #endif |
| 110 | |
| 111 | #endif /* __ASM_IMAGE_H */ |