1 /*-
2 * Copyright (c) 2008-2010 Rui Paulo <rpaulo@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/types.h>
31 #include <elf.h>
32 #include <efi.h>
33 #include <bootstrap.h>
34
35 #if defined(__aarch64__)
36 #define ElfW_Rel Elf64_Rela
37 #define ElfW_Dyn Elf64_Dyn
38 #define ELFW_R_TYPE ELF64_R_TYPE
39 #define ELF_RELA
40 #elif defined(__arm__) || defined(__i386__)
41 #define ElfW_Rel Elf32_Rel
42 #define ElfW_Dyn Elf32_Dyn
43 #define ELFW_R_TYPE ELF32_R_TYPE
44 #elif defined(__amd64__)
45 #define ElfW_Rel Elf64_Rel
46 #define ElfW_Dyn Elf64_Dyn
47 #define ELFW_R_TYPE ELF64_R_TYPE
48 #else
49 #error architecture not supported
50 #endif
51 #if defined(__aarch64__)
52 #define RELOC_TYPE_NONE R_AARCH64_NONE
53 #define RELOC_TYPE_RELATIVE R_AARCH64_RELATIVE
54 #elif defined(__amd64__)
55 #define RELOC_TYPE_NONE R_X86_64_NONE
56 #define RELOC_TYPE_RELATIVE R_X86_64_RELATIVE
57 #elif defined(__arm__)
58 #define RELOC_TYPE_NONE R_ARM_NONE
59 #define RELOC_TYPE_RELATIVE R_ARM_RELATIVE
60 #elif defined(__i386__)
61 #define RELOC_TYPE_NONE R_386_NONE
62 #define RELOC_TYPE_RELATIVE R_386_RELATIVE
63 #endif
64
65 /*
66 * A simple relocator for EFI binaries.
67 */
68 EFI_STATUS
_reloc(unsigned long ImageBase,ElfW_Dyn * dynamic,EFI_HANDLE image_handle,EFI_SYSTEM_TABLE * system_table)69 _reloc(unsigned long ImageBase, ElfW_Dyn *dynamic, EFI_HANDLE image_handle,
70 EFI_SYSTEM_TABLE *system_table)
71 {
72 unsigned long relsz, relent;
73 unsigned long *newaddr;
74 ElfW_Rel *rel;
75 ElfW_Dyn *dynp;
76
77 /*
78 * Find the relocation address, its size and the relocation entry.
79 */
80 relsz = 0;
81 relent = 0;
82 for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) {
83 switch (dynp->d_tag) {
84 case DT_REL:
85 case DT_RELA:
86 rel = (ElfW_Rel *) ((unsigned long) dynp->d_un.d_ptr +
87 ImageBase);
88 break;
89 case DT_RELSZ:
90 case DT_RELASZ:
91 relsz = dynp->d_un.d_val;
92 break;
93 case DT_RELENT:
94 case DT_RELAENT:
95 relent = dynp->d_un.d_val;
96 break;
97 default:
98 break;
99 }
100 }
101
102 /*
103 * Perform the actual relocation.
104 */
105 for (; relsz > 0; relsz -= relent) {
106 switch (ELFW_R_TYPE(rel->r_info)) {
107 case RELOC_TYPE_NONE:
108 /* No relocation needs be performed. */
109 break;
110
111 case RELOC_TYPE_RELATIVE:
112 /* Address relative to the base address. */
113 newaddr = (unsigned long *)(ImageBase + rel->r_offset);
114 *newaddr += ImageBase;
115 /* Add the addend when the ABI uses them */
116 #ifdef ELF_RELA
117 *newaddr += rel->r_addend;
118 #endif
119 break;
120 default:
121 /* XXX: do we need other relocations ? */
122 break;
123 }
124 rel = (ElfW_Rel *) ((caddr_t) rel + relent);
125 }
126
127 return (EFI_SUCCESS);
128 }
129