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Diffstat (limited to 'arch/arm64/kernel/image.h')
| -rw-r--r-- | arch/arm64/kernel/image.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h new file mode 100644 index 000000000..eff6a564a --- /dev/null +++ b/arch/arm64/kernel/image.h @@ -0,0 +1,116 @@ +/* + * 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 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * 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 <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_IMAGE_H +#define __ASM_IMAGE_H + +#ifndef LINKER_SCRIPT +#error This file should only be included in vmlinux.lds.S +#endif + +/* + * 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) + +#ifdef CONFIG_CPU_BIG_ENDIAN +#define __HEAD_FLAG_BE 1 +#else +#define __HEAD_FLAG_BE 0 +#endif + +#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) + +#define __HEAD_FLAG_PHYS_BASE 1 + +#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \ + (__HEAD_FLAG_PAGE_SIZE << 1) | \ + (__HEAD_FLAG_PHYS_BASE << 3)) + +/* + * 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); + +#ifdef CONFIG_EFI + +/* + * Use ABSOLUTE() to avoid ld.lld treating this as a relative symbol: + * https://github.com/ClangBuiltLinux/linux/issues/561 + */ +__efistub_stext_offset = ABSOLUTE(stext - _text); + +/* + * 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 = __pi_memcmp; +__efistub_memchr = __pi_memchr; +__efistub_memcpy = __pi_memcpy; +__efistub_memmove = __pi_memmove; +__efistub_memset = __pi_memset; +__efistub_strlen = __pi_strlen; +__efistub_strnlen = __pi_strnlen; +__efistub_strcmp = __pi_strcmp; +__efistub_strncmp = __pi_strncmp; +__efistub_strrchr = __pi_strrchr; +__efistub___flush_dcache_area = __pi___flush_dcache_area; + +#ifdef CONFIG_KASAN +__efistub___memcpy = __pi_memcpy; +__efistub___memmove = __pi_memmove; +__efistub___memset = __pi_memset; +#endif + +__efistub__text = _text; +__efistub__end = _end; +__efistub__edata = _edata; +__efistub_screen_info = screen_info; + +#endif + +#endif /* __ASM_IMAGE_H */ |