xref: /openbmc/u-boot/arch/x86/lib/relocate.c (revision 32cd2512)
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 		/* Get the location from the relocation entry */
57 		offset_ptr_rom = (Elf64_Addr *)(uintptr_t)re_src->r_offset;
58 
59 		/* Check that the location of the relocation is in .text */
60 		if (offset_ptr_rom >= (Elf64_Addr *)(uintptr_t)text_base &&
61 		    offset_ptr_rom > last_offset) {
62 			/* Switch to the in-RAM version */
63 			offset_ptr_ram = (Elf64_Addr *)((ulong)offset_ptr_rom +
64 							gd->reloc_off);
65 
66 			/* Check that the target points into .text */
67 			if (*offset_ptr_ram >= text_base &&
68 			    *offset_ptr_ram <= text_base + size) {
69 				*offset_ptr_ram = gd->reloc_off +
70 							re_src->r_addend;
71 			} else {
72 				debug("   %p: %lx: rom reloc %lx, ram %p, value %lx, limit %lX\n",
73 				      re_src, (ulong)re_src->r_info,
74 				      (ulong)re_src->r_offset, offset_ptr_ram,
75 				      (ulong)*offset_ptr_ram, text_base + size);
76 			}
77 		} else {
78 			debug("   %p: %lx: rom reloc %lx, last %p\n", re_src,
79 			      (ulong)re_src->r_info, (ulong)re_src->r_offset,
80 			      last_offset);
81 		}
82 		last_offset = offset_ptr_rom;
83 
84 	} while (++re_src < re_end);
85 }
86 #else
87 static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size,
88 				  Elf32_Rel *re_src, Elf32_Rel *re_end)
89 {
90 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
91 	Elf32_Addr *offset_ptr_ram;
92 
93 	do {
94 		/* Get the location from the relocation entry */
95 		offset_ptr_rom = (Elf32_Addr *)(uintptr_t)re_src->r_offset;
96 
97 		/* Check that the location of the relocation is in .text */
98 		if (offset_ptr_rom >= (Elf32_Addr *)(uintptr_t)text_base &&
99 		    offset_ptr_rom > last_offset) {
100 
101 			/* Switch to the in-RAM version */
102 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
103 							gd->reloc_off);
104 
105 			/* Check that the target points into .text */
106 			if (*offset_ptr_ram >= text_base &&
107 			    *offset_ptr_ram <= text_base + size) {
108 				*offset_ptr_ram += gd->reloc_off;
109 			} else {
110 				debug("   %p: rom reloc %x, ram %p, value %x, limit %lX\n",
111 				      re_src, re_src->r_offset, offset_ptr_ram,
112 				      *offset_ptr_ram, text_base + size);
113 			}
114 		} else {
115 			debug("   %p: rom reloc %x, last %p\n", re_src,
116 			       re_src->r_offset, last_offset);
117 		}
118 		last_offset = offset_ptr_rom;
119 
120 	} while (++re_src < re_end);
121 }
122 #endif
123 
124 /*
125  * This function has more error checking than you might expect. Please see
126  * this commit message for more information:
127  *    62f7970a x86: Add error checking to x86 relocation code
128  */
129 int do_elf_reloc_fixups(void)
130 {
131 	void *re_src = (void *)(&__rel_dyn_start);
132 	void *re_end = (void *)(&__rel_dyn_end);
133 	uint text_base;
134 
135 	/* The size of the region of u-boot that runs out of RAM. */
136 	uintptr_t size = (uintptr_t)&__bss_end - (uintptr_t)&__text_start;
137 
138 	if (gd->flags & GD_FLG_SKIP_RELOC)
139 		return 0;
140 	if (re_src == re_end)
141 		panic("No relocation data");
142 
143 #ifdef CONFIG_SYS_TEXT_BASE
144 	text_base = CONFIG_SYS_TEXT_BASE;
145 #else
146 	panic("No CONFIG_SYS_TEXT_BASE");
147 #endif
148 #if CONFIG_IS_ENABLED(X86_64)
149 	do_elf_reloc_fixups64(text_base, size, re_src, re_end);
150 #else
151 	do_elf_reloc_fixups32(text_base, size, re_src, re_end);
152 #endif
153 
154 	return 0;
155 }
156