1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Linker script macros to generate Image header fields. 4 * 5 * Copyright (C) 2014 ARM Ltd. 6 */ 7 #ifndef __ARM64_KERNEL_IMAGE_H 8 #define __ARM64_KERNEL_IMAGE_H 9 10 #ifndef LINKER_SCRIPT 11 #error This file should only be included in vmlinux.lds.S 12 #endif 13 14 #include <asm/image.h> 15 16 /* 17 * There aren't any ELF relocations we can use to endian-swap values known only 18 * at link time (e.g. the subtraction of two symbol addresses), so we must get 19 * the linker to endian-swap certain values before emitting them. 20 * 21 * Note that, in order for this to work when building the ELF64 PIE executable 22 * (for KASLR), these values should not be referenced via R_AARCH64_ABS64 23 * relocations, since these are fixed up at runtime rather than at build time 24 * when PIE is in effect. So we need to split them up in 32-bit high and low 25 * words. 26 */ 27 #ifdef CONFIG_CPU_BIG_ENDIAN 28 #define DATA_LE32(data) \ 29 ((((data) & 0x000000ff) << 24) | \ 30 (((data) & 0x0000ff00) << 8) | \ 31 (((data) & 0x00ff0000) >> 8) | \ 32 (((data) & 0xff000000) >> 24)) 33 #else 34 #define DATA_LE32(data) ((data) & 0xffffffff) 35 #endif 36 37 #define DEFINE_IMAGE_LE64(sym, data) \ 38 sym##_lo32 = DATA_LE32((data) & 0xffffffff); \ 39 sym##_hi32 = DATA_LE32((data) >> 32) 40 41 #define __HEAD_FLAG(field) (__HEAD_FLAG_##field << \ 42 ARM64_IMAGE_FLAG_##field##_SHIFT) 43 44 #ifdef CONFIG_CPU_BIG_ENDIAN 45 #define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_BE 46 #else 47 #define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_LE 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) | \ 55 __HEAD_FLAG(PAGE_SIZE) | \ 56 __HEAD_FLAG(PHYS_BASE)) 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 DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \ 65 DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \ 66 DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS); 67 68 #ifdef CONFIG_EFI 69 70 /* 71 * Use ABSOLUTE() to avoid ld.lld treating this as a relative symbol: 72 * https://github.com/ClangBuiltLinux/linux/issues/561 73 */ 74 __efistub_stext_offset = ABSOLUTE(stext - _text); 75 76 /* 77 * The EFI stub has its own symbol namespace prefixed by __efistub_, to 78 * isolate it from the kernel proper. The following symbols are legally 79 * accessed by the stub, so provide some aliases to make them accessible. 80 * Only include data symbols here, or text symbols of functions that are 81 * guaranteed to be safe when executed at another offset than they were 82 * linked at. The routines below are all implemented in assembler in a 83 * position independent manner 84 */ 85 __efistub_memcmp = __pi_memcmp; 86 __efistub_memchr = __pi_memchr; 87 __efistub_memcpy = __pi_memcpy; 88 __efistub_memmove = __pi_memmove; 89 __efistub_memset = __pi_memset; 90 __efistub_strlen = __pi_strlen; 91 __efistub_strnlen = __pi_strnlen; 92 __efistub_strcmp = __pi_strcmp; 93 __efistub_strncmp = __pi_strncmp; 94 __efistub_strrchr = __pi_strrchr; 95 __efistub___flush_dcache_area = __pi___flush_dcache_area; 96 97 #ifdef CONFIG_KASAN 98 __efistub___memcpy = __pi_memcpy; 99 __efistub___memmove = __pi_memmove; 100 __efistub___memset = __pi_memset; 101 #endif 102 103 __efistub__text = _text; 104 __efistub__end = _end; 105 __efistub__edata = _edata; 106 __efistub_screen_info = screen_info; 107 108 #endif 109 110 #endif /* __ARM64_KERNEL_IMAGE_H */ 111