xref: /openbmc/u-boot/arch/x86/lib/relocate.c (revision 20c700f8)
1 /*
2  * (C) Copyright 2008-2011
3  * Graeme Russ, <graeme.russ@gmail.com>
4  *
5  * (C) Copyright 2002
6  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
7  *
8  * (C) Copyright 2002
9  * Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
10  *
11  * (C) Copyright 2002
12  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
13  * Marius Groeger <mgroeger@sysgo.de>
14  *
15  * SPDX-License-Identifier:	GPL-2.0+
16  */
17 
18 #include <common.h>
19 #include <inttypes.h>
20 #include <asm/u-boot-x86.h>
21 #include <asm/relocate.h>
22 #include <asm/sections.h>
23 #include <elf.h>
24 
25 DECLARE_GLOBAL_DATA_PTR;
26 
27 int copy_uboot_to_ram(void)
28 {
29 	size_t len = (size_t)&__data_end - (size_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 
38 int clear_bss(void)
39 {
40 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
41 	size_t len = (size_t)&__bss_end - (size_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 /*
51  * This function has more error checking than you might expect. Please see
52  * the commit message for more informaiton.
53  */
54 int do_elf_reloc_fixups(void)
55 {
56 	Elf32_Rel *re_src = (Elf32_Rel *)(&__rel_dyn_start);
57 	Elf32_Rel *re_end = (Elf32_Rel *)(&__rel_dyn_end);
58 
59 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
60 	Elf32_Addr *offset_ptr_ram;
61 	unsigned int text_base = 0;
62 
63 	/* The size of the region of u-boot that runs out of RAM. */
64 	uintptr_t size = (uintptr_t)&__bss_end - (uintptr_t)&__text_start;
65 
66 	if (gd->flags & GD_FLG_SKIP_RELOC)
67 		return 0;
68 	if (re_src == re_end)
69 		panic("No relocation data");
70 
71 #ifdef CONFIG_SYS_TEXT_BASE
72 	text_base = CONFIG_SYS_TEXT_BASE;
73 #else
74 	panic("No CONFIG_SYS_TEXT_BASE");
75 #endif
76 	do {
77 		/* Get the location from the relocation entry */
78 		offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
79 
80 		/* Check that the location of the relocation is in .text */
81 		if (offset_ptr_rom >= (Elf32_Addr *)text_base &&
82 		    offset_ptr_rom > last_offset) {
83 
84 			/* Switch to the in-RAM version */
85 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
86 							gd->reloc_off);
87 
88 			/* Check that the target points into .text */
89 			if (*offset_ptr_ram >= text_base &&
90 			    *offset_ptr_ram <= text_base + size) {
91 				*offset_ptr_ram += gd->reloc_off;
92 			} else {
93 				debug("   %p: rom reloc %x, ram %p, value %x,"
94 					" limit %" PRIXPTR "\n", re_src,
95 					re_src->r_offset, offset_ptr_ram,
96 					*offset_ptr_ram,
97 					text_base + size);
98 			}
99 		} else {
100 			debug("   %p: rom reloc %x, last %p\n", re_src,
101 			       re_src->r_offset, last_offset);
102 		}
103 		last_offset = offset_ptr_rom;
104 
105 	} while (++re_src < re_end);
106 
107 	return 0;
108 }
109