1 /* BFD backend for CRIS a.out binaries.
2 Copyright 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Axis Communications AB.
4 Written by Hans-Peter Nilsson.
5
6 This file is part of BFD, the Binary File Descriptor library.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
21
22 /* See info in the file PORTING for documentation of these macros and
23 functions. Beware; some of the information there is outdated. */
24
25 #define N_HEADER_IN_TEXT(x) 0
26 #define N_TXTOFF(x) 32
27 #define ENTRY_CAN_BE_ZERO
28 #define TEXT_START_ADDR 0
29
30 /* Without reading symbols to get the text start symbol, there is no way
31 to know where the text segment starts in an a.out file. Defaulting to
32 anything as constant as TEXT_START_ADDR is bad. But we can guess from
33 the entry point, which is usually within the first 64k of the text
34 segment. We also assume here that the text segment is 64k-aligned.
35 FIXME: It is also wrong to assume that data and bss follow immediately
36 after text, but with those, we don't have any choice besides reading
37 symbol info, and luckily there's no pressing need for correctness for
38 those vma:s at this time. */
39 #define N_TXTADDR(x) ((x).a_entry & ~(bfd_vma) 0xffff)
40
41 /* If you change this to 4, you can not link to an address N*4+2. */
42 #define SEGMENT_SIZE 2
43
44 /* For some reason, if the a.out file has Z_MAGIC, then
45 adata(abfd).exec_bytes_size is not used, but rather
46 adata(abfd).zmagic_disk_block_size, even though the exec_header is
47 *not* included in the text segment. A simple workaround is to
48 #define ZMAGIC_DISK_BLOCK_SIZE, which is used if defined; otherwise
49 TARGET_PAGE_SIZE is used. */
50 #define ZMAGIC_DISK_BLOCK_SIZE N_TXTOFF (0)
51
52 /* It seems odd at first to set a page-size this low, but gives greater
53 freedom in where things can be linked. The drawback is that you have
54 to set alignment and padding in linker scripts. */
55 #define TARGET_PAGE_SIZE SEGMENT_SIZE
56 #define TARGETNAME "a.out-cris"
57
58 /* N_SHARED_LIB gets this reasonable default as of 1999-07-12, but we
59 have to work with 2.9.1. Note that N_SHARED_LIB is used in a
60 SUN-specific context, not applicable to CRIS. */
61 #define N_SHARED_LIB(x) 0
62
63 /* The definition here seems not used; just provided as a convention. */
64 #define DEFAULT_ARCH bfd_arch_cris
65
66 /* Do not "beautify" the CONCAT* macro args. Traditional C will not
67 remove whitespace added here, and thus will fail to concatenate
68 the tokens. */
69 #define MY(OP) CONCAT2 (cris_aout_,OP)
70 #define NAME(x, y) CONCAT3 (cris_aout,_32_,y)
71
72 #include "bfd.h"
73
74 /* Version 1 of the header. */
75 #define MY_exec_hdr_flags 1
76
77 #define MY_write_object_contents MY (write_object_contents)
78 static bfd_boolean MY (write_object_contents) (bfd *);
79
80 /* Forward this, so we can use a pointer to it in PARAMS. */
81 struct reloc_ext_external;
82
83 #define MY_swap_ext_reloc_out MY (swap_ext_reloc_out)
84 static void MY (swap_ext_reloc_out) (bfd *, arelent *, struct reloc_ext_external *);
85
86 #define MY_swap_ext_reloc_in MY (swap_ext_reloc_in)
87 static void MY (swap_ext_reloc_in) (bfd *, struct reloc_ext_external *,
88 arelent *, asymbol **, bfd_size_type);
89
90 #define MY_set_sizes MY (set_sizes)
91 static bfd_boolean MY (set_sizes) (bfd *);
92
93 /* To set back reloc_size to ext, we make MY (set_sizes) be called
94 through this construct. Note that MY_set_arch_mach is only called
95 through SET_ARCH_MACH. The default bfd_default_set_arch_mach will
96 not call set_sizes. */
97
98 #define MY_set_arch_mach NAME (aout, set_arch_mach)
99 #define SET_ARCH_MACH(BFD, EXEC) \
100 MY_set_arch_mach (BFD, DEFAULT_ARCH, N_MACHTYPE (EXEC))
101
102 /* These macros describe the binary layout of the reloc information we
103 use in a file. */
104 #define RELOC_EXT_BITS_EXTERN_LITTLE 0x80
105 #define RELOC_EXT_BITS_TYPE_LITTLE 3
106 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 0
107
108 #ifndef MY_get_section_contents
109 #define MY_get_section_contents aout_32_get_section_contents
110 #endif
111
112 #define MACHTYPE_OK(mtype) ((mtype) == M_CRIS)
113
114 /* Include generic functions (some are overridden above). */
115 #include "aout32.c"
116 #include "aout-target.h"
117
118 /* We need our own version to set header flags. */
119
120 static bfd_boolean
MY(write_object_contents)121 MY (write_object_contents) (bfd *abfd)
122 {
123 struct external_exec exec_bytes;
124 struct internal_exec *execp = exec_hdr (abfd);
125
126 /* We set the reloc type to RELOC_EXT_SIZE, although setting it at all
127 seems unnecessary when inspecting as and ld behavior (not an
128 exhaustive inspection). The default write_object_contents
129 definition sets RELOC_EXT_SIZE, so we follow suite and set it too. */
130 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;
131
132 /* Setting N_SET_MACHTYPE and using N_SET_FLAGS is not performed by
133 the default definition. */
134 if (bfd_get_arch (abfd) == bfd_arch_cris)
135 N_SET_MACHTYPE (*execp, M_CRIS);
136
137 N_SET_FLAGS (*execp, aout_backend_info (abfd)->exec_hdr_flags);
138
139 WRITE_HEADERS (abfd, execp);
140
141 return TRUE;
142 }
143
144 /* We need our own for these reasons:
145 - Assert that a normal 8, 16 or 32 reloc is output.
146 - Fix what seems to be a weak-bug (perhaps there for valid reasons). */
147
148 static void
MY(swap_ext_reloc_out)149 MY (swap_ext_reloc_out) (bfd *abfd,
150 arelent *g,
151 struct reloc_ext_external *natptr)
152 {
153 int r_index;
154 int r_extern;
155 unsigned int r_type;
156 bfd_vma r_addend;
157 asymbol *sym = *(g->sym_ptr_ptr);
158 asection *output_section = sym->section->output_section;
159
160 PUT_WORD (abfd, g->address, natptr->r_address);
161
162 r_type = (unsigned int) g->howto->type;
163
164 r_addend = g->addend;
165 if ((sym->flags & BSF_SECTION_SYM) != 0)
166 r_addend += (*(g->sym_ptr_ptr))->section->output_section->vma;
167
168 /* If this relocation is relative to a symbol then set the
169 r_index to the symbols index, and the r_extern bit.
170
171 Absolute symbols can come in in two ways, either as an offset
172 from the abs section, or as a symbol which has an abs value.
173 check for that here. */
174
175 if (bfd_is_abs_section (bfd_get_section (sym)))
176 {
177 r_extern = 0;
178 r_index = N_ABS;
179 }
180 else if ((sym->flags & BSF_SECTION_SYM) == 0)
181 {
182 if (bfd_is_und_section (bfd_get_section (sym))
183 /* Remember to check for weak symbols; they count as global. */
184 || (sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0)
185 r_extern = 1;
186 else
187 r_extern = 0;
188 r_index = (*(g->sym_ptr_ptr))->KEEPIT;
189 }
190 else
191 {
192 /* Just an ordinary section. */
193 r_extern = 0;
194 r_index = output_section->target_index;
195 }
196
197 /* The relocation type is the same as the canonical ones, but only
198 the first 3 are used: RELOC_8, RELOC_16, RELOC_32.
199 We may change this later, but assert this for the moment. */
200 if (r_type > 2)
201 {
202 (*_bfd_error_handler) (_("%s: Invalid relocation type exported: %d"),
203 bfd_get_filename (abfd), r_type);
204
205 bfd_set_error (bfd_error_wrong_format);
206 }
207
208 /* Now the fun stuff. */
209 natptr->r_index[2] = r_index >> 16;
210 natptr->r_index[1] = r_index >> 8;
211 natptr->r_index[0] = r_index;
212 natptr->r_type[0] =
213 (r_extern ? RELOC_EXT_BITS_EXTERN_LITTLE : 0)
214 | (r_type << RELOC_EXT_BITS_TYPE_SH_LITTLE);
215
216 PUT_WORD (abfd, r_addend, natptr->r_addend);
217 }
218
219 /* We need our own to assert that a normal 8, 16 or 32 reloc is input. */
220
221 static void
MY(swap_ext_reloc_in)222 MY (swap_ext_reloc_in) (bfd *abfd,
223 struct reloc_ext_external *bytes,
224 arelent *cache_ptr,
225 asymbol **symbols,
226 bfd_size_type symcount)
227 {
228 unsigned int r_index;
229 int r_extern;
230 unsigned int r_type;
231 struct aoutdata *su = &(abfd->tdata.aout_data->a);
232
233 cache_ptr->address = (GET_SWORD (abfd, bytes->r_address));
234
235 /* Now the fun stuff. */
236 r_index = (bytes->r_index[2] << 16)
237 | (bytes->r_index[1] << 8)
238 | bytes->r_index[0];
239 r_extern = (0 != (bytes->r_type[0] & RELOC_EXT_BITS_EXTERN_LITTLE));
240 r_type = ((bytes->r_type[0]) >> RELOC_EXT_BITS_TYPE_SH_LITTLE)
241 & RELOC_EXT_BITS_TYPE_LITTLE;
242
243 if (r_type > 2)
244 {
245 (*_bfd_error_handler) (_("%B: Invalid relocation type imported: %d"),
246 abfd, r_type);
247
248 bfd_set_error (bfd_error_wrong_format);
249 }
250
251 cache_ptr->howto = howto_table_ext + r_type;
252
253 if (r_extern && r_index > symcount)
254 {
255 (*_bfd_error_handler)
256 (_("%B: Bad relocation record imported: %d"), abfd, r_index);
257
258 bfd_set_error (bfd_error_wrong_format);
259
260 /* We continue, so we can catch further errors. */
261 r_extern = 0;
262 r_index = N_ABS;
263 }
264
265 /* Magically uses r_extern, symbols etc. Ugly, but it's what's in the
266 default. */
267 MOVE_ADDRESS (GET_SWORD (abfd, bytes->r_addend));
268 }
269
270 /* We use the same as the default, except that we also set
271 "obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;", to avoid changing
272 NAME (aout, set_arch_mach) in aoutx. */
273
274 static bfd_boolean
MY(set_sizes)275 MY (set_sizes) (bfd *abfd)
276 {
277 /* Just as the default in aout-target.h (with some #ifdefs folded)... */
278
279 adata (abfd).page_size = TARGET_PAGE_SIZE;
280 adata (abfd).segment_size = SEGMENT_SIZE;
281 adata (abfd).zmagic_disk_block_size = ZMAGIC_DISK_BLOCK_SIZE;
282 adata (abfd).exec_bytes_size = EXEC_BYTES_SIZE;
283
284 /* ... except for that we have the extended reloc. The alternative
285 would be to add a check on bfd_arch_cris in NAME (aout,
286 set_arch_mach) in aoutx.h, but I don't want to do that since
287 target-specific things should not be added there. */
288
289 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;
290
291 return TRUE;
292 }
293