xref: /openbmc/u-boot/arch/x86/lib/relocate.c (revision ae485b54)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2008-2011
4  * Graeme Russ, <graeme.russ@gmail.com>
5  *
6  * (C) Copyright 2002
7  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
8  *
9  * (C) Copyright 2002
10  * Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
11  *
12  * (C) Copyright 2002
13  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
14  * Marius Groeger <mgroeger@sysgo.de>
15  */
16 
17 #include <common.h>
18 #include <inttypes.h>
19 #include <relocate.h>
20 #include <asm/u-boot-x86.h>
21 #include <asm/sections.h>
22 #include <elf.h>
23 
24 DECLARE_GLOBAL_DATA_PTR;
25 
26 int copy_uboot_to_ram(void)
27 {
28 	size_t len = (uintptr_t)&__data_end - (uintptr_t)&__text_start;
29 
30 	if (gd->flags & GD_FLG_SKIP_RELOC)
31 		return 0;
32 	memcpy((void *)gd->relocaddr, (void *)&__text_start, len);
33 
34 	return 0;
35 }
36 
37 int clear_bss(void)
38 {
39 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
40 	size_t len = (uintptr_t)&__bss_end - (uintptr_t)&__bss_start;
41 
42 	if (gd->flags & GD_FLG_SKIP_RELOC)
43 		return 0;
44 	memset((void *)dst_addr, 0x00, len);
45 
46 	return 0;
47 }
48 
49 #if CONFIG_IS_ENABLED(X86_64)
50 static void do_elf_reloc_fixups64(unsigned int text_base, uintptr_t size,
51 				  Elf64_Rela *re_src, Elf64_Rela *re_end)
52 {
53 	Elf64_Addr *offset_ptr_rom, *last_offset = NULL;
54 	Elf64_Addr *offset_ptr_ram;
55 
56 	do {
57 		/* Get the location from the relocation entry */
58 		offset_ptr_rom = (Elf64_Addr *)(uintptr_t)re_src->r_offset;
59 
60 		/* Check that the location of the relocation is in .text */
61 		if (offset_ptr_rom >= (Elf64_Addr *)(uintptr_t)text_base &&
62 		    offset_ptr_rom > last_offset) {
63 			/* Switch to the in-RAM version */
64 			offset_ptr_ram = (Elf64_Addr *)((ulong)offset_ptr_rom +
65 							gd->reloc_off);
66 
67 			/* Check that the target points into .text */
68 			if (*offset_ptr_ram >= text_base &&
69 			    *offset_ptr_ram <= text_base + size) {
70 				*offset_ptr_ram = gd->reloc_off +
71 							re_src->r_addend;
72 			} else {
73 				debug("   %p: %lx: rom reloc %lx, ram %p, value %lx, limit %"
74 				      PRIXPTR "\n",
75 				      re_src, (ulong)re_src->r_info,
76 				      (ulong)re_src->r_offset, offset_ptr_ram,
77 				      (ulong)*offset_ptr_ram, text_base + size);
78 			}
79 		} else {
80 			debug("   %p: %lx: rom reloc %lx, last %p\n", re_src,
81 			      (ulong)re_src->r_info, (ulong)re_src->r_offset,
82 			      last_offset);
83 		}
84 		last_offset = offset_ptr_rom;
85 
86 	} while (++re_src < re_end);
87 }
88 #else
89 static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size,
90 				  Elf32_Rel *re_src, Elf32_Rel *re_end)
91 {
92 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
93 	Elf32_Addr *offset_ptr_ram;
94 
95 	do {
96 		/* Get the location from the relocation entry */
97 		offset_ptr_rom = (Elf32_Addr *)(uintptr_t)re_src->r_offset;
98 
99 		/* Check that the location of the relocation is in .text */
100 		if (offset_ptr_rom >= (Elf32_Addr *)(uintptr_t)text_base &&
101 		    offset_ptr_rom > last_offset) {
102 
103 			/* Switch to the in-RAM version */
104 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
105 							gd->reloc_off);
106 
107 			/* Check that the target points into .text */
108 			if (*offset_ptr_ram >= text_base &&
109 			    *offset_ptr_ram <= text_base + size) {
110 				*offset_ptr_ram += gd->reloc_off;
111 			} else {
112 				debug("   %p: rom reloc %x, ram %p, value %x,"
113 					" limit %" PRIXPTR "\n", re_src,
114 					re_src->r_offset, offset_ptr_ram,
115 					*offset_ptr_ram,
116 					text_base + size);
117 			}
118 		} else {
119 			debug("   %p: rom reloc %x, last %p\n", re_src,
120 			       re_src->r_offset, last_offset);
121 		}
122 		last_offset = offset_ptr_rom;
123 
124 	} while (++re_src < re_end);
125 }
126 #endif
127 
128 /*
129  * This function has more error checking than you might expect. Please see
130  * this commit message for more information:
131  *    62f7970a x86: Add error checking to x86 relocation code
132  */
133 int do_elf_reloc_fixups(void)
134 {
135 	void *re_src = (void *)(&__rel_dyn_start);
136 	void *re_end = (void *)(&__rel_dyn_end);
137 	uint text_base;
138 
139 	/* The size of the region of u-boot that runs out of RAM. */
140 	uintptr_t size = (uintptr_t)&__bss_end - (uintptr_t)&__text_start;
141 
142 	if (gd->flags & GD_FLG_SKIP_RELOC)
143 		return 0;
144 	if (re_src == re_end)
145 		panic("No relocation data");
146 
147 #ifdef CONFIG_SYS_TEXT_BASE
148 	text_base = CONFIG_SYS_TEXT_BASE;
149 #else
150 	panic("No CONFIG_SYS_TEXT_BASE");
151 #endif
152 #if CONFIG_IS_ENABLED(X86_64)
153 	do_elf_reloc_fixups64(text_base, size, re_src, re_end);
154 #else
155 	do_elf_reloc_fixups32(text_base, size, re_src, re_end);
156 #endif
157 
158 	return 0;
159 }
160