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 #define DEFINE_IMAGE_LE64(sym, data) \ 28 sym##_lo32 = (data) & 0xffffffff; \ 29 sym##_hi32 = (data) >> 32 30 31 #define __HEAD_FLAG(field) (__HEAD_FLAG_##field << \ 32 ARM64_IMAGE_FLAG_##field##_SHIFT) 33 34 #define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_LE 35 36 #define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) 37 38 #define __HEAD_FLAG_PHYS_BASE 1 39 40 #define __HEAD_FLAGS (__HEAD_FLAG(BE) | \ 41 __HEAD_FLAG(PAGE_SIZE) | \ 42 __HEAD_FLAG(PHYS_BASE)) 43 44 /* 45 * These will output as part of the Image header, which should be little-endian 46 * regardless of the endianness of the kernel. While constant values could be 47 * endian swapped in head.S, all are done here for consistency. 48 */ 49 #define HEAD_SYMBOLS \ 50 DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \ 51 DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS); 52 53 #endif /* __ARM64_KERNEL_IMAGE_H */ 54