xref: /openbmc/u-boot/arch/arc/lib/relocate.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
4  */
5 
6 #include <common.h>
7 #include <elf.h>
8 #include <asm-generic/sections.h>
9 
10 extern ulong __image_copy_start;
11 extern ulong __ivt_end;
12 
13 DECLARE_GLOBAL_DATA_PTR;
14 
15 int copy_uboot_to_ram(void)
16 {
17 	size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
18 
19 	if (gd->flags & GD_FLG_SKIP_RELOC)
20 		return 0;
21 
22 	memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
23 
24 	return 0;
25 }
26 
27 int clear_bss(void)
28 {
29 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
30 	size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
31 
32 	memset((void *)dst_addr, 0x00, len);
33 
34 	return 0;
35 }
36 
37 /*
38  * Base functionality is taken from x86 version with added ARC-specifics
39  */
40 int do_elf_reloc_fixups(void)
41 {
42 	Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
43 	Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
44 
45 	if (gd->flags & GD_FLG_SKIP_RELOC)
46 		return 0;
47 
48 	debug("Section .rela.dyn is located at %08x-%08x\n",
49 	      (unsigned int)re_src, (unsigned int)re_end);
50 
51 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
52 	Elf32_Addr *offset_ptr_ram;
53 
54 	do {
55 		/* Get the location from the relocation entry */
56 		offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
57 
58 		/* Check that the location of the relocation is in .text */
59 		if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
60 		    offset_ptr_rom > last_offset) {
61 			unsigned int val;
62 			/* Switch to the in-RAM version */
63 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
64 							gd->reloc_off);
65 
66 			debug("Patching value @ %08x (relocated to %08x)\n",
67 			      (unsigned int)offset_ptr_rom,
68 			      (unsigned int)offset_ptr_ram);
69 
70 			/*
71 			 * Use "memcpy" because target location might be
72 			 * 16-bit aligned on ARC so we may need to read
73 			 * byte-by-byte. On attempt to read entire word by
74 			 * CPU throws an exception
75 			 */
76 			memcpy(&val, offset_ptr_ram, sizeof(int));
77 
78 #ifdef __LITTLE_ENDIAN__
79 			/* If location in ".text" section swap value */
80 			if ((unsigned int)offset_ptr_rom <
81 			    (unsigned int)&__ivt_end)
82 				val = (val << 16) | (val >> 16);
83 #endif
84 
85 			/* Check that the target points into executable */
86 			if (val >= (unsigned int)&__image_copy_start && val <=
87 			    (unsigned int)&__image_copy_end) {
88 				val += gd->reloc_off;
89 #ifdef __LITTLE_ENDIAN__
90 				/* If location in ".text" section swap value */
91 				if ((unsigned int)offset_ptr_rom <
92 				    (unsigned int)&__ivt_end)
93 					val = (val << 16) | (val >> 16);
94 #endif
95 				memcpy(offset_ptr_ram, &val, sizeof(int));
96 			}
97 		}
98 		last_offset = offset_ptr_rom;
99 
100 	} while (++re_src < re_end);
101 
102 	return 0;
103 }
104