1 /*
2  * (C) Copyright 2017 NVIDIA Corporation <www.nvidia.com>
3  *
4  * Derived from Linux kernel v4.14 files:
5  *
6  * arch/arm64/include/asm/assembler.h:
7  * Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S
8  * Copyright (C) 1996-2000 Russell King
9  * Copyright (C) 2012 ARM Ltd.
10  *
11  * arch/arm64/kernel/head.S:
12  * Based on arch/arm/kernel/head.S
13  * Copyright (C) 1994-2002 Russell King
14  * Copyright (C) 2003-2012 ARM Ltd.
15  * Authors:	Catalin Marinas <catalin.marinas@arm.com>
16  *		Will Deacon <will.deacon@arm.com>
17  *
18  * arch/arm64/kernel/image.h:
19  * Copyright (C) 2014 ARM Ltd.
20  *
21  * SPDX-License-Identifier:     GPL-2.0
22  */
23 
24 /*
25  * There aren't any ELF relocations we can use to endian-swap values known only
26  * at link time (e.g. the subtraction of two symbol addresses), so we must get
27  * the linker to endian-swap certain values before emitting them.
28  *
29  * Note that, in order for this to work when building the ELF64 PIE executable
30  * (for KASLR), these values should not be referenced via R_AARCH64_ABS64
31  * relocations, since these are fixed up at runtime rather than at build time
32  * when PIE is in effect. So we need to split them up in 32-bit high and low
33  * words.
34  */
35 #ifdef CONFIG_CPU_BIG_ENDIAN
36 #define DATA_LE32(data)				\
37 	((((data) & 0x000000ff) << 24) |	\
38 	 (((data) & 0x0000ff00) << 8)  |	\
39 	 (((data) & 0x00ff0000) >> 8)  |	\
40 	 (((data) & 0xff000000) >> 24))
41 #else
42 #define DATA_LE32(data) ((data) & 0xffffffff)
43 #endif
44 
45 #define DEFINE_IMAGE_LE64(sym, data)				\
46 	sym##_lo32 = DATA_LE32((data) & 0xffffffff);		\
47 	sym##_hi32 = DATA_LE32((data) >> 32)
48 
49 #define __MAX(a, b)		(((a) > (b)) ? (a) : (b))
50 #define __CODE_DATA_SIZE	(__bss_start - _start)
51 #define __BSS_SIZE		(__bss_end - __bss_start)
52 #ifdef CONFIG_SYS_INIT_SP_BSS_OFFSET
53 #define __MAX_EXTRA_RAM_USAGE	__MAX(__BSS_SIZE, CONFIG_SYS_INIT_SP_BSS_OFFSET)
54 #else
55 #define __MAX_EXTRA_RAM_USAGE	__BSS_SIZE
56 #endif
57 #define __MEM_USAGE		(__CODE_DATA_SIZE + __MAX_EXTRA_RAM_USAGE)
58 
59 #ifdef CONFIG_CPU_BIG_ENDIAN
60 #define __HEAD_FLAG_BE		1
61 #else
62 #define __HEAD_FLAG_BE		0
63 #endif
64 
65 #define __HEAD_FLAG_PAGE_SIZE	1 /* 4K hard-coded */
66 
67 #define __HEAD_FLAG_PHYS_BASE	1
68 
69 #define __HEAD_FLAGS		((__HEAD_FLAG_BE << 0) |	\
70 				 (__HEAD_FLAG_PAGE_SIZE << 1) |	\
71 				 (__HEAD_FLAG_PHYS_BASE << 3))
72 
73 #define TEXT_OFFSET (CONFIG_SYS_TEXT_BASE - \
74 			CONFIG_LNX_KRNL_IMG_TEXT_OFFSET_BASE)
75 
76 /*
77  * These will output as part of the Image header, which should be little-endian
78  * regardless of the endianness of the kernel. While constant values could be
79  * endian swapped in head.S, all are done here for consistency.
80  */
81 #define HEAD_SYMBOLS						\
82 	DEFINE_IMAGE_LE64(_kernel_size_le, __MEM_USAGE);	\
83 	DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET);	\
84 	DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
85 
86 	HEAD_SYMBOLS
87