7709633d5be124d610f9ceef86a6b90c7ee669ec
[people/ms/u-boot.git] / arch / arc / lib / relocate.c
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         debug("Section .rela.dyn is located at %08x-%08x\n",
41               (unsigned int)re_src, (unsigned int)re_end);
42
43         Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
44         Elf32_Addr *offset_ptr_ram;
45
46         do {
47                 /* Get the location from the relocation entry */
48                 offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
49
50                 /* Check that the location of the relocation is in .text */
51                 if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
52                     offset_ptr_rom > last_offset) {
53                         unsigned int val;
54                         /* Switch to the in-RAM version */
55                         offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
56                                                         gd->reloc_off);
57
58                         debug("Patching value @ %08x (relocated to %08x)\n",
59                               (unsigned int)offset_ptr_rom,
60                               (unsigned int)offset_ptr_ram);
61
62                         /*
63                          * Use "memcpy" because target location might be
64                          * 16-bit aligned on ARC so we may need to read
65                          * byte-by-byte. On attempt to read entire word by
66                          * CPU throws an exception
67                          */
68                         memcpy(&val, offset_ptr_ram, sizeof(int));
69
70 #ifdef __LITTLE_ENDIAN__
71                         /* If location in ".text" section swap value */
72                         if ((unsigned int)offset_ptr_rom <
73                             (unsigned int)&__ivt_end)
74                                 val = (val << 16) | (val >> 16);
75 #endif
76
77                         /* Check that the target points into executable */
78                         if (val >= (unsigned int)&__image_copy_start && val <=
79                             (unsigned int)&__image_copy_end) {
80                                 val += gd->reloc_off;
81 #ifdef __LITTLE_ENDIAN__
82                                 /* If location in ".text" section swap value */
83                                 if ((unsigned int)offset_ptr_rom <
84                                     (unsigned int)&__ivt_end)
85                                         val = (val << 16) | (val >> 16);
86 #endif
87                                 memcpy(offset_ptr_ram, &val, sizeof(int));
88                         }
89                 }
90                 last_offset = offset_ptr_rom;
91
92         } while (++re_src < re_end);
93
94         return 0;
95 }