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 */ 112