xref: /openbmc/u-boot/arch/x86/lib/relocate.c (revision dd1033e4)
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 <relocate.h>
19 #include <asm/u-boot-x86.h>
20 #include <asm/sections.h>
21 #include <elf.h>
22 
23 DECLARE_GLOBAL_DATA_PTR;
24 
25 int copy_uboot_to_ram(void)
26 {
27 	size_t len = (uintptr_t)&__data_end - (uintptr_t)&__text_start;
28 
29 	if (gd->flags & GD_FLG_SKIP_RELOC)
30 		return 0;
31 	memcpy((void *)gd->relocaddr, (void *)&__text_start, len);
32 
33 	return 0;
34 }
35 
36 int clear_bss(void)
37 {
38 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
39 	size_t len = (uintptr_t)&__bss_end - (uintptr_t)&__bss_start;
40 
41 	if (gd->flags & GD_FLG_SKIP_RELOC)
42 		return 0;
43 	memset((void *)dst_addr, 0x00, len);
44 
45 	return 0;
46 }
47 
48 #if CONFIG_IS_ENABLED(X86_64)
49 static void do_elf_reloc_fixups64(unsigned int text_base, uintptr_t size,
50 				  Elf64_Rela *re_src, Elf64_Rela *re_end)
51 {
52 	Elf64_Addr *offset_ptr_rom, *last_offset = NULL;
53 	Elf64_Addr *offset_ptr_ram;
54 
55 	do {
56 		unsigned long long type = ELF64_R_TYPE(re_src->r_info);
57 
58 		if (type != R_X86_64_RELATIVE) {
59 			printf("%s: unsupported relocation type 0x%llx "
60 			       "at %p, ", __func__, type, re_src);
61 			printf("offset = 0x%llx\n", re_src->r_offset);
62 			continue;
63 		}
64 
65 		/* Get the location from the relocation entry */
66 		offset_ptr_rom = (Elf64_Addr *)(uintptr_t)re_src->r_offset;
67 
68 		/* Check that the location of the relocation is in .text */
69 		if (offset_ptr_rom >= (Elf64_Addr *)(uintptr_t)text_base &&
70 		    offset_ptr_rom > last_offset) {
71 			/* Switch to the in-RAM version */
72 			offset_ptr_ram = (Elf64_Addr *)((ulong)offset_ptr_rom +
73 							gd->reloc_off);
74 
75 			/* Check that the target points into .text */
76 			if (*offset_ptr_ram >= text_base &&
77 			    *offset_ptr_ram <= text_base + size) {
78 				*offset_ptr_ram = gd->reloc_off +
79 							re_src->r_addend;
80 			} else {
81 				debug("   %p: %lx: rom reloc %lx, ram %p, value %lx, limit %lX\n",
82 				      re_src, (ulong)re_src->r_info,
83 				      (ulong)re_src->r_offset, offset_ptr_ram,
84 				      (ulong)*offset_ptr_ram, text_base + size);
85 			}
86 		} else {
87 			debug("   %p: %lx: rom reloc %lx, last %p\n", re_src,
88 			      (ulong)re_src->r_info, (ulong)re_src->r_offset,
89 			      last_offset);
90 		}
91 		last_offset = offset_ptr_rom;
92 
93 	} while (++re_src < re_end);
94 }
95 #else
96 static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size,
97 				  Elf32_Rel *re_src, Elf32_Rel *re_end)
98 {
99 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
100 	Elf32_Addr *offset_ptr_ram;
101 
102 	do {
103 		unsigned int type = ELF32_R_TYPE(re_src->r_info);
104 
105 		if (type != R_386_RELATIVE) {
106 			printf("%s: unsupported relocation type 0x%x "
107 			       "at %p, ", __func__, type, re_src);
108 			printf("offset = 0x%x\n", re_src->r_offset);
109 			continue;
110 		}
111 
112 		/* Get the location from the relocation entry */
113 		offset_ptr_rom = (Elf32_Addr *)(uintptr_t)re_src->r_offset;
114 
115 		/* Check that the location of the relocation is in .text */
116 		if (offset_ptr_rom >= (Elf32_Addr *)(uintptr_t)text_base &&
117 		    offset_ptr_rom > last_offset) {
118 
119 			/* Switch to the in-RAM version */
120 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
121 							gd->reloc_off);
122 
123 			/* Check that the target points into .text */
124 			if (*offset_ptr_ram >= text_base &&
125 			    *offset_ptr_ram <= text_base + size) {
126 				*offset_ptr_ram += gd->reloc_off;
127 			} else {
128 				debug("   %p: rom reloc %x, ram %p, value %x, limit %lX\n",
129 				      re_src, re_src->r_offset, offset_ptr_ram,
130 				      *offset_ptr_ram, text_base + size);
131 			}
132 		} else {
133 			debug("   %p: rom reloc %x, last %p\n", re_src,
134 			       re_src->r_offset, last_offset);
135 		}
136 		last_offset = offset_ptr_rom;
137 
138 	} while (++re_src < re_end);
139 }
140 #endif
141 
142 /*
143  * This function has more error checking than you might expect. Please see
144  * this commit message for more information:
145  *    62f7970a x86: Add error checking to x86 relocation code
146  */
147 int do_elf_reloc_fixups(void)
148 {
149 	void *re_src = (void *)(&__rel_dyn_start);
150 	void *re_end = (void *)(&__rel_dyn_end);
151 	uint text_base;
152 
153 	/* The size of the region of u-boot that runs out of RAM. */
154 	uintptr_t size = (uintptr_t)&__bss_end - (uintptr_t)&__text_start;
155 
156 	if (gd->flags & GD_FLG_SKIP_RELOC)
157 		return 0;
158 	if (re_src == re_end)
159 		panic("No relocation data");
160 
161 #ifdef CONFIG_SYS_TEXT_BASE
162 	text_base = CONFIG_SYS_TEXT_BASE;
163 #else
164 	panic("No CONFIG_SYS_TEXT_BASE");
165 #endif
166 #if CONFIG_IS_ENABLED(X86_64)
167 	do_elf_reloc_fixups64(text_base, size, re_src, re_end);
168 #else
169 	do_elf_reloc_fixups32(text_base, size, re_src, re_end);
170 #endif
171 
172 	return 0;
173 }
174