linux/arch/arm64/kernel/image.h

69 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Linker script macros to generate Image header fields.
*
* Copyright (C) 2014 ARM Ltd.
*/
#ifndef __ARM64_KERNEL_IMAGE_H
#define __ARM64_KERNEL_IMAGE_H
#ifndef LINKER_SCRIPT
#error This file should only be included in vmlinux.lds.S
#endif
#include <asm/image.h>
/*
* There aren't any ELF relocations we can use to endian-swap values known only
* at link time (e.g. the subtraction of two symbol addresses), so we must get
* the linker to endian-swap certain values before emitting them.
*
* Note that, in order for this to work when building the ELF64 PIE executable
* (for KASLR), these values should not be referenced via R_AARCH64_ABS64
* relocations, since these are fixed up at runtime rather than at build time
* when PIE is in effect. So we need to split them up in 32-bit high and low
* words.
*/
#ifdef CONFIG_CPU_BIG_ENDIAN
#define DATA_LE32(data) \
((((data) & 0x000000ff) << 24) | \
(((data) & 0x0000ff00) << 8) | \
(((data) & 0x00ff0000) >> 8) | \
(((data) & 0xff000000) >> 24))
#else
#define DATA_LE32(data) ((data) & 0xffffffff)
#endif
#define DEFINE_IMAGE_LE64(sym, data) \
sym##_lo32 = DATA_LE32((data) & 0xffffffff); \
sym##_hi32 = DATA_LE32((data) >> 32)
#define __HEAD_FLAG(field) (__HEAD_FLAG_##field << \
ARM64_IMAGE_FLAG_##field##_SHIFT)
#ifdef CONFIG_CPU_BIG_ENDIAN
#define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_BE
#else
#define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_LE
#endif
#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
#define __HEAD_FLAG_PHYS_BASE 1
#define __HEAD_FLAGS (__HEAD_FLAG(BE) | \
__HEAD_FLAG(PAGE_SIZE) | \
__HEAD_FLAG(PHYS_BASE))
/*
* These will output as part of the Image header, which should be little-endian
* regardless of the endianness of the kernel. While constant values could be
* endian swapped in head.S, all are done here for consistency.
*/
#define HEAD_SYMBOLS \
DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \
DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \
DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
#endif /* __ARM64_KERNEL_IMAGE_H */