2 * Linker script macros to generate Image header fields.
4 * Copyright (C) 2014 ARM Ltd.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #error This file should only be included in vmlinux.lds.S
26 * There aren't any ELF relocations we can use to endian-swap values known only
27 * at link time (e.g. the subtraction of two symbol addresses), so we must get
28 * the linker to endian-swap certain values before emitting them.
30 #ifdef CONFIG_CPU_BIG_ENDIAN
31 #define DATA_LE64(data) \
32 ((((data) & 0x00000000000000ff) << 56) | \
33 (((data) & 0x000000000000ff00) << 40) | \
34 (((data) & 0x0000000000ff0000) << 24) | \
35 (((data) & 0x00000000ff000000) << 8) | \
36 (((data) & 0x000000ff00000000) >> 8) | \
37 (((data) & 0x0000ff0000000000) >> 24) | \
38 (((data) & 0x00ff000000000000) >> 40) | \
39 (((data) & 0xff00000000000000) >> 56))
41 #define DATA_LE64(data) ((data) & 0xffffffffffffffff)
44 #ifdef CONFIG_CPU_BIG_ENDIAN
45 #define __HEAD_FLAG_BE 1
47 #define __HEAD_FLAG_BE 0
50 #define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
52 #define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \
53 (__HEAD_FLAG_PAGE_SIZE << 1))
56 * These will output as part of the Image header, which should be little-endian
57 * regardless of the endianness of the kernel. While constant values could be
58 * endian swapped in head.S, all are done here for consistency.
60 #define HEAD_SYMBOLS \
61 _kernel_size_le = DATA_LE64(_end - _text); \
62 _kernel_offset_le = DATA_LE64(TEXT_OFFSET); \
63 _kernel_flags_le = DATA_LE64(__HEAD_FLAGS);
68 * Prevent the symbol aliases below from being emitted into the kallsyms
69 * table, by forcing them to be absolute symbols (which are conveniently
70 * ignored by scripts/kallsyms) rather than section relative symbols.
71 * The distinction is only relevant for partial linking, and only for symbols
72 * that are defined within a section declaration (which is not the case for
73 * the definitions below) so the resulting values will be identical.
75 #define KALLSYMS_HIDE(sym) ABSOLUTE(sym)
78 * The EFI stub has its own symbol namespace prefixed by __efistub_, to
79 * isolate it from the kernel proper. The following symbols are legally
80 * accessed by the stub, so provide some aliases to make them accessible.
81 * Only include data symbols here, or text symbols of functions that are
82 * guaranteed to be safe when executed at another offset than they were
83 * linked at. The routines below are all implemented in assembler in a
84 * position independent manner
86 __efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp);
87 __efistub_memchr = KALLSYMS_HIDE(__pi_memchr);
88 __efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy);
89 __efistub_memmove = KALLSYMS_HIDE(__pi_memmove);
90 __efistub_memset = KALLSYMS_HIDE(__pi_memset);
91 __efistub_strlen = KALLSYMS_HIDE(__pi_strlen);
92 __efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp);
93 __efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp);
94 __efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area);
97 __efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy);
98 __efistub___memmove = KALLSYMS_HIDE(__pi_memmove);
99 __efistub___memset = KALLSYMS_HIDE(__pi_memset);
102 __efistub__text = KALLSYMS_HIDE(_text);
103 __efistub__end = KALLSYMS_HIDE(_end);
104 __efistub__edata = KALLSYMS_HIDE(_edata);
108 #endif /* __ASM_IMAGE_H */