blob: 5e360ce88f10ba4110697552a47ea8c42053a02f [file] [log] [blame]
* Linker script macros to generate Image header fields.
* Copyright (C) 2014 ARM Ltd.
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <>.
#ifndef __ASM_IMAGE_H
#define __ASM_IMAGE_H
#error This file should only be included in
* 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.
#define DATA_LE32(data) \
((((data) & 0x000000ff) << 24) | \
(((data) & 0x0000ff00) << 8) | \
(((data) & 0x00ff0000) >> 8) | \
(((data) & 0xff000000) >> 24))
#define DATA_LE32(data) ((data) & 0xffffffff)
#define DEFINE_IMAGE_LE64(sym, data) \
sym##_lo32 = DATA_LE32((data) & 0xffffffff); \
sym##_hi32 = DATA_LE32((data) >> 32)
#define __HEAD_FLAG_BE 1
#define __HEAD_FLAG_BE 0
#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \
(__HEAD_FLAG_PAGE_SIZE << 1) | \
* 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);
* Prevent the symbol aliases below from being emitted into the kallsyms
* table, by forcing them to be absolute symbols (which are conveniently
* ignored by scripts/kallsyms) rather than section relative symbols.
* The distinction is only relevant for partial linking, and only for symbols
* that are defined within a section declaration (which is not the case for
* the definitions below) so the resulting values will be identical.
#define KALLSYMS_HIDE(sym) ABSOLUTE(sym)
* The EFI stub has its own symbol namespace prefixed by __efistub_, to
* isolate it from the kernel proper. The following symbols are legally
* accessed by the stub, so provide some aliases to make them accessible.
* Only include data symbols here, or text symbols of functions that are
* guaranteed to be safe when executed at another offset than they were
* linked at. The routines below are all implemented in assembler in a
* position independent manner
__efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp);
__efistub_memchr = KALLSYMS_HIDE(__pi_memchr);
__efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy);
__efistub_memmove = KALLSYMS_HIDE(__pi_memmove);
__efistub_memset = KALLSYMS_HIDE(__pi_memset);
__efistub_strlen = KALLSYMS_HIDE(__pi_strlen);
__efistub_strnlen = KALLSYMS_HIDE(__pi_strnlen);
__efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp);
__efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp);
__efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area);
__efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy);
__efistub___memmove = KALLSYMS_HIDE(__pi_memmove);
__efistub___memset = KALLSYMS_HIDE(__pi_memset);
__efistub__text = KALLSYMS_HIDE(_text);
__efistub__end = KALLSYMS_HIDE(_end);
__efistub__edata = KALLSYMS_HIDE(_edata);
#endif /* __ASM_IMAGE_H */