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_flags_le, __HEAD_FLAGS);
66
67#endif /* __ARM64_KERNEL_IMAGE_H */