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d03d5626 ILT |
1 | /* PowerPC-specific support for 32-bit ELF |
2 | Copyright 1994 Free Software Foundation, Inc. | |
3 | Written by Ian Lance Taylor, Cygnus Support. | |
4 | ||
5 | This file is part of BFD, the Binary File Descriptor library. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | /* I wrote this file without the benefit of a PowerPC ELF ABI. Thus, | |
22 | it probably does not correspond to whatever people finally settle | |
23 | on. Ian Taylor. */ | |
24 | ||
25 | #include "bfd.h" | |
26 | #include "sysdep.h" | |
27 | #include "libbfd.h" | |
28 | #include "libelf.h" | |
29 | ||
30 | static bfd_reloc_status_type powerpc_elf_toc16_reloc PARAMS ((bfd *abfd, | |
31 | arelent *reloc, | |
32 | asymbol *symbol, | |
33 | PTR data, | |
34 | asection *sec, | |
35 | bfd *output_bfd, | |
36 | char **error)); | |
37 | static bfd_reloc_status_type powerpc_elf_b26_reloc PARAMS ((bfd *abfd, | |
38 | arelent *reloc, | |
39 | asymbol *symbol, | |
40 | PTR data, | |
41 | asection *sec, | |
42 | bfd *output_bfd, | |
43 | char **error)); | |
44 | static const struct reloc_howto_struct *bfd_elf32_bfd_reloc_type_lookup | |
45 | PARAMS ((bfd *abfd, bfd_reloc_code_real_type code)); | |
46 | static void powerpc_info_to_howto_rel | |
47 | PARAMS ((bfd *abfd, arelent *cache_ptr, Elf32_Internal_Rel *dst)); | |
48 | ||
49 | #define USE_REL | |
50 | ||
51 | enum reloc_type | |
52 | { | |
53 | R_POWERPC_NONE = 0, | |
54 | R_POWERPC_32, | |
55 | R_POWERPC_B26, | |
56 | R_POWERPC_BA26, | |
57 | R_POWERPC_TOC16, | |
58 | R_POWERPC_max | |
59 | }; | |
60 | ||
61 | static reloc_howto_type elf_powerpc_howto_table[] = | |
62 | { | |
63 | /* This relocation does not do anything. */ | |
64 | HOWTO (R_POWERPC_NONE, /* type */ | |
65 | 0, /* rightshift */ | |
66 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
67 | 32, /* bitsize */ | |
68 | false, /* pc_relative */ | |
69 | 0, /* bitpos */ | |
70 | complain_overflow_bitfield, /* complain_on_overflow */ | |
71 | bfd_elf_generic_reloc, /* special_function */ | |
72 | "R_POWERPC_NONE", /* name */ | |
73 | true, /* partial_inplace */ | |
74 | 0, /* src_mask */ | |
75 | 0, /* dst_mask */ | |
76 | false), /* pcrel_offset */ | |
77 | ||
78 | /* Standard 32 bit relocation. */ | |
79 | HOWTO (R_POWERPC_32, /* type */ | |
80 | 0, /* rightshift */ | |
81 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
82 | 32, /* bitsize */ | |
83 | false, /* pc_relative */ | |
84 | 0, /* bitpos */ | |
85 | complain_overflow_bitfield, /* complain_on_overflow */ | |
86 | bfd_elf_generic_reloc, /* special_function */ | |
87 | "R_POWERPC_32", /* name */ | |
88 | true, /* partial_inplace */ | |
89 | 0xffffffff, /* src_mask */ | |
90 | 0xffffffff, /* dst_mask */ | |
91 | false), /* pcrel_offset */ | |
92 | ||
93 | /* 26 bit relative branch. */ | |
94 | HOWTO (R_POWERPC_B26, /* type */ | |
95 | 0, /* rightshift */ | |
96 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
97 | 26, /* bitsize */ | |
98 | true, /* pc_relative */ | |
99 | 0, /* bitpos */ | |
100 | complain_overflow_signed, /* complain_on_overflow */ | |
101 | powerpc_elf_b26_reloc, /* special_function */ | |
102 | "R_POWERPC_B26", /* name */ | |
103 | true, /* partial_inplace */ | |
104 | 0x3fffffc, /* src_mask */ | |
105 | 0x3fffffc, /* dst_mask */ | |
106 | false), /* pcrel_offset */ | |
107 | ||
108 | /* 26 bit absolute branch. */ | |
109 | HOWTO (R_POWERPC_BA26, /* type */ | |
110 | 0, /* rightshift */ | |
111 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
112 | 26, /* bitsize */ | |
113 | false, /* pc_relative */ | |
114 | 0, /* bitpos */ | |
115 | complain_overflow_bitfield, /* complain_on_overflow */ | |
116 | bfd_elf_generic_reloc, /* special_function */ | |
117 | "R_POWERPC_BA26", /* name */ | |
118 | true, /* partial_inplace */ | |
119 | 0x3fffffc, /* src_mask */ | |
120 | 0x3fffffc, /* dst_mask */ | |
121 | false), /* pcrel_offset */ | |
122 | ||
123 | /* 16 bit reference to TOC section. */ | |
124 | HOWTO (R_POWERPC_TOC16, /* type */ | |
125 | 0, /* rightshift */ | |
126 | 1, /* size (0 = byte, 1 = short, 2 = long) */ | |
127 | 16, /* bitsize */ | |
128 | false, /* pc_relative */ | |
129 | 0, /* bitpos */ | |
130 | complain_overflow_signed, /* complain_on_overflow */ | |
131 | powerpc_elf_toc16_reloc, /* special_function */ | |
132 | "R_POWERPC_TOC16", /* name */ | |
133 | true, /* partial_inplace */ | |
134 | 0xffff, /* src_mask */ | |
135 | 0xffff, /* dst_mask */ | |
136 | false), /* pcrel_offset */ | |
137 | }; | |
138 | ||
139 | /* Handle the TOC16 reloc. We want to use the offset within the .toc | |
140 | section, not the actual VMA. */ | |
141 | ||
142 | static bfd_reloc_status_type | |
143 | powerpc_elf_toc16_reloc (abfd, | |
144 | reloc_entry, | |
145 | symbol, | |
146 | data, | |
147 | input_section, | |
148 | output_bfd, | |
149 | error_message) | |
150 | bfd *abfd; | |
151 | arelent *reloc_entry; | |
152 | asymbol *symbol; | |
153 | PTR data; | |
154 | asection *input_section; | |
155 | bfd *output_bfd; | |
156 | char **error_message; | |
157 | { | |
158 | asection *sec; | |
159 | ||
160 | /* Simply adjust the reloc addend by the negative of the VMA of the | |
161 | .toc section. */ | |
162 | sec = bfd_get_section (*reloc_entry->sym_ptr_ptr); | |
163 | if (sec == &bfd_und_section) | |
164 | return bfd_reloc_continue; | |
165 | BFD_ASSERT (strcmp (bfd_get_section_name (abfd, sec), ".toc") == 0); | |
166 | reloc_entry->addend -= sec->output_section->vma; | |
167 | return bfd_reloc_continue; | |
168 | } | |
169 | ||
170 | /* Handle a branch. If the next instruction is the special | |
171 | instruction "cror 31,31,31", and this branch is to a stub routine | |
172 | we have created, we must change the cror instruction into an | |
173 | instruction which reloads the TOC register. We can detect a stub | |
174 | routine because it is in a BFD named "linker stubs". FIXME: What a | |
175 | hack. */ | |
176 | ||
177 | static bfd_reloc_status_type | |
178 | powerpc_elf_b26_reloc (abfd, | |
179 | reloc_entry, | |
180 | symbol, | |
181 | data, | |
182 | input_section, | |
183 | output_bfd, | |
184 | error_message) | |
185 | bfd *abfd; | |
186 | arelent *reloc_entry; | |
187 | asymbol *symbol; | |
188 | PTR data; | |
189 | asection *input_section; | |
190 | bfd *output_bfd; | |
191 | char **error_message; | |
192 | { | |
193 | if (bfd_get_section (symbol) != &bfd_und_section | |
194 | && (strcmp (bfd_get_section (symbol)->owner->filename, "linker stubs") | |
195 | == 0)) | |
196 | { | |
197 | bfd_vma val; | |
198 | ||
199 | /* This symbol is a stub created by the linker. */ | |
200 | val = bfd_get_32 (abfd, (bfd_byte *) data + reloc_entry->address + 4); | |
201 | if (val == 0x4ffffb82) /* cror 31,31,31 */ | |
202 | bfd_put_32 (abfd, (bfd_vma) 0x80410014, /* l r2,20(r1) */ | |
203 | (bfd_byte *) data + reloc_entry->address + 4); | |
204 | } | |
205 | ||
206 | if (output_bfd != (bfd *) NULL | |
207 | && bfd_get_section (symbol) == &bfd_und_section) | |
208 | { | |
209 | bfd_size_type address; | |
210 | ||
211 | /* If we are generating relocateable output, and the symbol is | |
212 | undefined, we just want to adjust the reloc by the amount the | |
213 | section moved. */ | |
214 | address = reloc_entry->address; | |
215 | reloc_entry->address += input_section->output_offset; | |
216 | return _bfd_relocate_contents (reloc_entry->howto, abfd, | |
217 | - input_section->output_offset, | |
218 | (bfd_byte *) data + address); | |
219 | } | |
220 | ||
221 | /* Otherwise, let bfd_perform_relocation handle it. */ | |
222 | return bfd_reloc_continue; | |
223 | } | |
224 | ||
225 | /* Map BFD reloc types to PowerPC ELF reloc types. */ | |
226 | ||
227 | struct powerpc_reloc_map | |
228 | { | |
229 | unsigned char bfd_reloc_val; | |
230 | unsigned char elf_reloc_val; | |
231 | }; | |
232 | ||
233 | static const struct powerpc_reloc_map powerpc_reloc_map[] = | |
234 | { | |
235 | { BFD_RELOC_NONE, R_POWERPC_NONE, }, | |
236 | { BFD_RELOC_32, R_POWERPC_32 }, | |
237 | { BFD_RELOC_CTOR, R_POWERPC_32 }, | |
238 | { BFD_RELOC_PPC_B26, R_POWERPC_B26 }, | |
239 | { BFD_RELOC_PPC_BA26, R_POWERPC_BA26 }, | |
240 | { BFD_RELOC_PPC_TOC16, R_POWERPC_TOC16 } | |
241 | }; | |
242 | ||
243 | static const struct reloc_howto_struct * | |
244 | bfd_elf32_bfd_reloc_type_lookup (abfd, code) | |
245 | bfd *abfd; | |
246 | bfd_reloc_code_real_type code; | |
247 | { | |
248 | int i; | |
249 | ||
250 | for (i = 0; | |
251 | i < sizeof (powerpc_reloc_map) / sizeof (struct powerpc_reloc_map); | |
252 | i++) | |
253 | { | |
254 | if (powerpc_reloc_map[i].bfd_reloc_val == code) | |
255 | return &elf_powerpc_howto_table[powerpc_reloc_map[i].elf_reloc_val]; | |
256 | } | |
257 | ||
258 | return NULL; | |
259 | } | |
260 | ||
261 | /* Set the howto pointer for a PowerPC ELF reloc. */ | |
262 | ||
263 | static void | |
264 | powerpc_info_to_howto_rel (abfd, cache_ptr, dst) | |
265 | bfd *abfd; | |
266 | arelent *cache_ptr; | |
267 | Elf32_Internal_Rel *dst; | |
268 | { | |
269 | BFD_ASSERT (ELF32_R_TYPE (dst->r_info) < (unsigned int) R_POWERPC_max); | |
270 | cache_ptr->howto = &elf_powerpc_howto_table[ELF32_R_TYPE(dst->r_info)]; | |
271 | } | |
272 | ||
273 | #define TARGET_BIG_SYM bfd_elf32_powerpc_vec | |
274 | #define TARGET_BIG_NAME "elf32-powerpc" | |
275 | #define ELF_ARCH bfd_arch_powerpc | |
276 | #define ELF_MACHINE_CODE EM_CYGNUS_POWERPC | |
277 | #define ELF_MAXPAGESIZE 0x10000 | |
278 | #define elf_info_to_howto 0 | |
279 | #define elf_info_to_howto_rel powerpc_info_to_howto_rel | |
280 | ||
281 | #include "elf32-target.h" |