xref: /openbmc/u-boot/arch/arc/lib/relocate.c (revision ed09a554)
1 /*
2  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <elf.h>
9 #include <asm/sections.h>
10 
11 DECLARE_GLOBAL_DATA_PTR;
12 
13 int copy_uboot_to_ram(void)
14 {
15 	size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
16 
17 	memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
18 
19 	return 0;
20 }
21 
22 int clear_bss(void)
23 {
24 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
25 	size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
26 
27 	memset((void *)dst_addr, 0x00, len);
28 
29 	return 0;
30 }
31 
32 /*
33  * Base functionality is taken from x86 version with added ARC-specifics
34  */
35 int do_elf_reloc_fixups(void)
36 {
37 	Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
38 	Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
39 
40 	Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
41 	Elf32_Addr *offset_ptr_ram;
42 
43 	do {
44 		/* Get the location from the relocation entry */
45 		offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
46 
47 		/* Check that the location of the relocation is in .text */
48 		if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
49 		    offset_ptr_rom > last_offset) {
50 			unsigned int val;
51 			/* Switch to the in-RAM version */
52 			offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
53 							gd->reloc_off);
54 
55 			/*
56 			 * Use "memcpy" because target location might be
57 			 * 16-bit aligned on ARC so we may need to read
58 			 * byte-by-byte. On attempt to read entire word by
59 			 * CPU throws an exception
60 			 */
61 			memcpy(&val, offset_ptr_ram, sizeof(int));
62 
63 #ifdef __LITTLE_ENDIAN__
64 			/* If location in ".text" section swap value */
65 			if ((unsigned int)offset_ptr_rom <
66 			    (unsigned int)&__ivt_end)
67 				val = (val << 16) | (val >> 16);
68 #endif
69 
70 			/* Check that the target points into executable */
71 			if (val >= (unsigned int)&__image_copy_start && val <=
72 			    (unsigned int)&__image_copy_end) {
73 				val += gd->reloc_off;
74 #ifdef __LITTLE_ENDIAN__
75 				/* If location in ".text" section swap value */
76 				if ((unsigned int)offset_ptr_rom <
77 				    (unsigned int)&__ivt_end)
78 					val = (val << 16) | (val >> 16);
79 #endif
80 				memcpy(offset_ptr_ram, &val, sizeof(int));
81 			}
82 		}
83 		last_offset = offset_ptr_rom;
84 
85 	} while (++re_src < re_end);
86 
87 	return 0;
88 }
89