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 <log.h>
19 #include <relocate.h>
20 #include <asm/global_data.h>
21 #include <asm/u-boot-x86.h>
22 #include <asm/sections.h>
23 #include <elf.h>
24 
25 DECLARE_GLOBAL_DATA_PTR;
26 
copy_uboot_to_ram(void)27 int copy_uboot_to_ram(void)
28 {
29 	size_t len = (uintptr_t)&__data_end - (uintptr_t)&__text_start;
30 
31 	if (gd->flags & GD_FLG_SKIP_RELOC)
32 		return 0;
33 	memcpy((void *)gd->relocaddr, (void *)&__text_start, len);
34 
35 	return 0;
36 }
37 
clear_bss(void)38 int clear_bss(void)
39 {
40 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
41 	size_t len = (uintptr_t)&__bss_end - (uintptr_t)&__bss_start;
42 
43 	if (gd->flags & GD_FLG_SKIP_RELOC)
44 		return 0;
45 	memset((void *)dst_addr, 0x00, len);
46 
47 	return 0;
48 }
49 
50 #if CONFIG_IS_ENABLED(X86_64)
do_elf_reloc_fixups64(unsigned int text_base,uintptr_t size,Elf64_Rela * re_src,Elf64_Rela * re_end)51 static void do_elf_reloc_fixups64(unsigned int text_base, uintptr_t size,
52 				  Elf64_Rela *re_src, Elf64_Rela *re_end)
53 {
54 	Elf64_Addr *offset_ptr_rom, *last_offset = NULL;
55 	Elf64_Addr *offset_ptr_ram;
56 
57 	do {
58 		unsigned long long type = ELF64_R_TYPE(re_src->r_info);
59 
60 		if (type != R_X86_64_RELATIVE) {
61 			printf("%s: unsupported relocation type 0x%llx "
62 			       "at %p, ", __func__, type, re_src);
63 			printf("offset = 0x%llx\n", re_src->r_offset);
64 			continue;
65 		}
66 
67 		/* Get the location from the relocation entry */
68 		offset_ptr_rom = (Elf64_Addr *)(uintptr_t)re_src->r_offset;
69 
70 		/* Check that the location of the relocation is in .text */
71 		if (offset_ptr_rom >= (Elf64_Addr *)(uintptr_t)text_base &&
72 		    offset_ptr_rom > last_offset) {
73 			/* Switch to the in-RAM version */
74 			offset_ptr_ram = (Elf64_Addr *)((ulong)offset_ptr_rom +
75 							gd->reloc_off);
76 
77 			/* Check that the target points into .text */
78 			if (*offset_ptr_ram >= text_base &&
79 			    *offset_ptr_ram <= text_base + size) {
80 				*offset_ptr_ram = gd->reloc_off +
81 							re_src->r_addend;
82 			} else {
83 				debug("   %p: %lx: rom reloc %lx, ram %p, value %lx, limit %lX\n",
84 				      re_src, (ulong)re_src->r_info,
85 				      (ulong)re_src->r_offset, offset_ptr_ram,
86 				      (ulong)*offset_ptr_ram, text_base + size);
87 			}
88 		} else {
89 			debug("   %p: %lx: rom reloc %lx, last %p\n", re_src,
90 			      (ulong)re_src->r_info, (ulong)re_src->r_offset,
91 			      last_offset);
92 		}
93 		last_offset = offset_ptr_rom;
94 
95 	} while (++re_src < re_end);
96 }
97 #else
do_elf_reloc_fixups32(unsigned int text_base,uintptr_t size,Elf32_Rel * re_src,Elf32_Rel * re_end)98 static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size,
99 				  Elf32_Rel *re_src, Elf32_Rel *re_end)
100 {
101 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
102 	Elf32_Addr *offset_ptr_ram;
103 
104 	do {
105 		unsigned int type = ELF32_R_TYPE(re_src->r_info);
106 
107 		if (type != R_386_RELATIVE) {
108 			printf("%s: unsupported relocation type 0x%x "
109 			       "at %p, ", __func__, type, re_src);
110 			printf("offset = 0x%x\n", re_src->r_offset);
111 			continue;
112 		}
113 
114 		/* Get the location from the relocation entry */
115 		offset_ptr_rom = (Elf32_Addr *)(uintptr_t)re_src->r_offset;
116 
117 		/* Check that the location of the relocation is in .text */
118 		if (offset_ptr_rom >= (Elf32_Addr *)(uintptr_t)text_base &&
119 		    offset_ptr_rom > last_offset) {
120 
121 			/* Switch to the in-RAM version */
122 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
123 							gd->reloc_off);
124 
125 			/* Check that the target points into .text */
126 			if (*offset_ptr_ram >= text_base &&
127 			    *offset_ptr_ram <= text_base + size) {
128 				*offset_ptr_ram += gd->reloc_off;
129 			} else {
130 				debug("   %p: rom reloc %x, ram %p, value %x, limit %lX\n",
131 				      re_src, re_src->r_offset, offset_ptr_ram,
132 				      *offset_ptr_ram, text_base + size);
133 			}
134 		} else {
135 			debug("   %p: rom reloc %x, last %p\n", re_src,
136 			       re_src->r_offset, last_offset);
137 		}
138 		last_offset = offset_ptr_rom;
139 
140 	} while (++re_src < re_end);
141 }
142 #endif
143 
144 /*
145  * This function has more error checking than you might expect. Please see
146  * this commit message for more information:
147  *    62f7970a x86: Add error checking to x86 relocation code
148  */
do_elf_reloc_fixups(void)149 int do_elf_reloc_fixups(void)
150 {
151 	void *re_src = (void *)(&__rel_dyn_start);
152 	void *re_end = (void *)(&__rel_dyn_end);
153 	uint text_base;
154 
155 	/* The size of the region of u-boot that runs out of RAM. */
156 	uintptr_t size = (uintptr_t)&__bss_end - (uintptr_t)&__text_start;
157 
158 	if (gd->flags & GD_FLG_SKIP_RELOC)
159 		return 0;
160 	if (re_src == re_end)
161 		panic("No relocation data");
162 
163 #ifdef CONFIG_SYS_TEXT_BASE
164 	text_base = CONFIG_SYS_TEXT_BASE;
165 #else
166 	panic("No CONFIG_SYS_TEXT_BASE");
167 #endif
168 #if CONFIG_IS_ENABLED(X86_64)
169 	do_elf_reloc_fixups64(text_base, size, re_src, re_end);
170 #else
171 	do_elf_reloc_fixups32(text_base, size, re_src, re_end);
172 #endif
173 
174 	return 0;
175 }
176