xref: /openbmc/linux/arch/arm64/kernel/image.h (revision 4f3db074)
1 /*
2  * Linker script macros to generate Image header fields.
3  *
4  * Copyright (C) 2014 ARM Ltd.
5  *
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.
9  *
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.
14  *
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/>.
17  */
18 #ifndef __ASM_IMAGE_H
19 #define __ASM_IMAGE_H
20 
21 #ifndef LINKER_SCRIPT
22 #error This file should only be included in vmlinux.lds.S
23 #endif
24 
25 /*
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.
29  */
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))
40 #else
41 #define DATA_LE64(data) ((data) & 0xffffffffffffffff)
42 #endif
43 
44 #ifdef CONFIG_CPU_BIG_ENDIAN
45 #define __HEAD_FLAG_BE	1
46 #else
47 #define __HEAD_FLAG_BE	0
48 #endif
49 
50 #define __HEAD_FLAGS	(__HEAD_FLAG_BE << 0)
51 
52 /*
53  * These will output as part of the Image header, which should be little-endian
54  * regardless of the endianness of the kernel. While constant values could be
55  * endian swapped in head.S, all are done here for consistency.
56  */
57 #define HEAD_SYMBOLS						\
58 	_kernel_size_le		= DATA_LE64(_end - _text);	\
59 	_kernel_offset_le	= DATA_LE64(TEXT_OFFSET);	\
60 	_kernel_flags_le	= DATA_LE64(__HEAD_FLAGS);
61 
62 #endif /* __ASM_IMAGE_H */
63