1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * reloc_arm.c - position-independent ARM ELF shared object relocator
4  *
5  * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
6  * Copyright (C) 1999 Hewlett-Packard Co.
7  * Contributed by David Mosberger <davidm@hpl.hp.com>.
8  *
9  * All rights reserved.
10  *
11  * This file is taken and modified from the gnu-efi project.
12  */
13 
14 #include <efi.h>
15 #include <elf.h>
16 
_relocate(long ldbase,Elf32_Dyn * dyn)17 efi_status_t EFIAPI _relocate(long ldbase, Elf32_Dyn *dyn)
18 {
19 	long relsz = 0, relent = 0;
20 	Elf32_Rel *rel = 0;
21 	ulong *addr;
22 	int i;
23 
24 	for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
25 		switch (dyn[i].d_tag) {
26 		case DT_REL:
27 			rel = (Elf32_Rel *)((ulong)dyn[i].d_un.d_ptr
28 					+ ldbase);
29 			break;
30 		case DT_RELSZ:
31 			relsz = dyn[i].d_un.d_val;
32 			break;
33 		case DT_RELENT:
34 			relent = dyn[i].d_un.d_val;
35 			break;
36 		default:
37 			break;
38 		}
39 	}
40 
41 	if (!rel && relent == 0)
42 		return EFI_SUCCESS;
43 
44 	if (!rel || relent == 0)
45 		return EFI_LOAD_ERROR;
46 
47 	while (relsz > 0) {
48 		/* apply the relocs */
49 		switch (ELF32_R_TYPE(rel->r_info)) {
50 		case R_ARM_NONE:
51 			break;
52 		case R_ARM_RELATIVE:
53 			addr = (ulong *)(ldbase + rel->r_offset);
54 			*addr += ldbase;
55 			break;
56 		default:
57 			break;
58 		}
59 		rel = (Elf32_Rel *)((char *)rel + relent);
60 		relsz -= relent;
61 	}
62 
63 	return EFI_SUCCESS;
64 }
65