bfd/
[binutils.git] / bfd / nlm32-i386.c
blobfcdfc645640b3daf9307d1b248fa2dfba41be1b9
1 /* Support for 32-bit i386 NLM (NetWare Loadable Module)
2 Copyright 1993, 1994, 2000, 2001, 2002, 2003, 2005
3 Free Software Foundation, Inc.
5 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
21 #include "bfd.h"
22 #include "sysdep.h"
23 #include "libbfd.h"
25 #define ARCH_SIZE 32
27 #include "nlm/i386-ext.h"
28 #define Nlm_External_Fixed_Header Nlm32_i386_External_Fixed_Header
30 #include "libnlm.h"
32 /* Adjust the reloc location by an absolute value. */
34 static reloc_howto_type nlm_i386_abs_howto =
35 HOWTO (0, /* Type. */
36 0, /* Rightshift. */
37 2, /* Size (0 = byte, 1 = short, 2 = long). */
38 32, /* Bitsize. */
39 FALSE, /* PC relative. */
40 0, /* Bitpos. */
41 complain_overflow_bitfield, /* Complain_on_overflow. */
42 0, /* Special_function. */
43 "32", /* Name. */
44 TRUE, /* Partial_inplace. */
45 0xffffffff, /* Source mask. */
46 0xffffffff, /* Dest mask. */
47 FALSE); /* PR rel_offset. */
49 /* Adjust the reloc location by a PC relative displacement. */
51 static reloc_howto_type nlm_i386_pcrel_howto =
52 HOWTO (1, /* Type. */
53 0, /* Rightshift. */
54 2, /* Size (0 = byte, 1 = short, 2 = long). */
55 32, /* Bitsize. */
56 TRUE, /* PC relative. */
57 0, /* Bitpos. */
58 complain_overflow_signed, /* Complain_on_overflow. */
59 0, /* Special_function. */
60 "DISP32", /* Name. */
61 TRUE, /* Partial_inplace. */
62 0xffffffff, /* Source mask. */
63 0xffffffff, /* Dest mask. */
64 TRUE); /* PR rel_offset. */
66 /* Read a NetWare i386 reloc. */
68 static bfd_boolean
69 nlm_i386_read_reloc (bfd *abfd,
70 nlmNAME (symbol_type) *sym,
71 asection **secp,
72 arelent *rel)
74 bfd_byte temp[4];
75 bfd_vma val;
76 const char *name;
78 if (bfd_bread (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
79 return FALSE;
81 val = bfd_get_32 (abfd, temp);
83 /* The value is an offset into either the code or data segment.
84 This is the location which needs to be adjusted.
86 If this is a relocation fixup rather than an imported symbol (the
87 sym argument is NULL) then the high bit is 0 if the location
88 needs to be adjusted by the address of the data segment, or 1 if
89 the location needs to be adjusted by the address of the code
90 segment. If this is an imported symbol, then the high bit is 0
91 if the location is 0 if the location should be adjusted by the
92 offset to the symbol, or 1 if the location should adjusted by the
93 absolute value of the symbol.
95 The second most significant bit is 0 if the value is an offset
96 into the data segment, or 1 if the value is an offset into the
97 code segment.
99 All this translates fairly easily into a BFD reloc. */
101 if (sym == NULL)
103 if ((val & NLM_HIBIT) == 0)
104 name = NLM_INITIALIZED_DATA_NAME;
105 else
107 name = NLM_CODE_NAME;
108 val &=~ NLM_HIBIT;
110 rel->sym_ptr_ptr = bfd_get_section_by_name (abfd, name)->symbol_ptr_ptr;
111 rel->howto = &nlm_i386_abs_howto;
113 else
115 /* In this case we do not need to set the sym_ptr_ptr field. */
116 rel->sym_ptr_ptr = NULL;
117 if ((val & NLM_HIBIT) == 0)
118 rel->howto = &nlm_i386_pcrel_howto;
119 else
121 rel->howto = &nlm_i386_abs_howto;
122 val &=~ NLM_HIBIT;
126 if ((val & (NLM_HIBIT >> 1)) == 0)
127 *secp = bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME);
128 else
130 *secp = bfd_get_section_by_name (abfd, NLM_CODE_NAME);
131 val &=~ (NLM_HIBIT >> 1);
134 rel->address = val;
135 rel->addend = 0;
137 return TRUE;
140 /* Write a NetWare i386 reloc. */
142 static bfd_boolean
143 nlm_i386_write_import (bfd * abfd, asection * sec, arelent * rel)
145 asymbol *sym;
146 bfd_vma val;
147 bfd_byte temp[4];
149 /* NetWare only supports two kinds of relocs. We should check
150 special_function here, as well, but at the moment coff-i386
151 relocs uses a special_function which does not affect what we do
152 here. */
153 if (rel->addend != 0
154 || rel->howto == NULL
155 || rel->howto->rightshift != 0
156 || rel->howto->size != 2
157 || rel->howto->bitsize != 32
158 || rel->howto->bitpos != 0
159 || rel->howto->src_mask != 0xffffffff
160 || rel->howto->dst_mask != 0xffffffff)
162 bfd_set_error (bfd_error_invalid_operation);
163 return FALSE;
166 sym = *rel->sym_ptr_ptr;
168 /* The value we write out is the offset into the appropriate
169 segment. This offset is the section vma, adjusted by the vma of
170 the lowest section in that segment, plus the address of the
171 relocation. */
172 val = bfd_get_section_vma (abfd, sec) + rel->address;
174 /* The second most significant bit is 0 if the value is an offset
175 into the data segment, or 1 if the value is an offset into the
176 code segment. */
177 if (bfd_get_section_flags (abfd, sec) & SEC_CODE)
179 val -= nlm_get_text_low (abfd);
180 val |= NLM_HIBIT >> 1;
182 else
183 val -= nlm_get_data_low (abfd);
185 if (! bfd_is_und_section (bfd_get_section (sym)))
187 /* NetWare only supports absolute internal relocs. */
188 if (rel->howto->pc_relative)
190 bfd_set_error (bfd_error_invalid_operation);
191 return FALSE;
194 /* The high bit is 1 if the reloc is against the code section, 0
195 if against the data section. */
196 if (bfd_get_section_flags (abfd, bfd_get_section (sym)) & SEC_CODE)
197 val |= NLM_HIBIT;
199 else
201 /* The high bit is 1 if this is an absolute reloc, 0 if it is PC
202 relative. */
203 if (! rel->howto->pc_relative)
204 val |= NLM_HIBIT;
205 else
207 /* PC relative relocs on NetWare must be pcrel_offset. */
208 if (! rel->howto->pcrel_offset)
210 bfd_set_error (bfd_error_invalid_operation);
211 return FALSE;
216 bfd_put_32 (abfd, val, temp);
217 if (bfd_bwrite (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
218 return FALSE;
220 return TRUE;
223 /* I want to be able to use objcopy to turn an i386 a.out or COFF file
224 into a NetWare i386 module. That means that the relocs from the
225 source file have to be mapped into relocs that apply to the target
226 file. This function is called by nlm_set_section_contents to give
227 it a chance to rework the relocs.
229 This is actually a fairly general concept. However, this is not a
230 general implementation. */
232 static bfd_boolean
233 nlm_i386_mangle_relocs (bfd *abfd,
234 asection *sec,
235 const PTR data,
236 bfd_vma offset,
237 bfd_size_type count)
239 arelent **rel_ptr_ptr, **rel_end;
241 rel_ptr_ptr = sec->orelocation;
242 rel_end = rel_ptr_ptr + sec->reloc_count;
243 for (; rel_ptr_ptr < rel_end; rel_ptr_ptr++)
245 arelent *rel;
246 asymbol *sym;
247 bfd_vma addend;
249 rel = *rel_ptr_ptr;
250 sym = *rel->sym_ptr_ptr;
252 /* Note that no serious harm will ensue if we fail to change a
253 reloc. We will wind up failing in nlm_i386_write_import. */
255 /* Make sure this reloc is within the data we have. We only 4
256 byte relocs here, so we insist on having 4 bytes. */
257 if (rel->address < offset
258 || rel->address + 4 > offset + count)
259 continue;
261 /* NetWare doesn't support reloc addends, so we get rid of them
262 here by simply adding them into the object data. We handle
263 the symbol value, if any, the same way. */
264 addend = rel->addend + sym->value;
266 /* The value of a symbol is the offset into the section. If the
267 symbol is in the .bss segment, we need to include the size of
268 the data segment in the offset as well. Fortunately, we know
269 that at this point the size of the data section is in the NLM
270 header. */
271 if (((bfd_get_section_flags (abfd, bfd_get_section (sym))
272 & SEC_LOAD) == 0)
273 && ((bfd_get_section_flags (abfd, bfd_get_section (sym))
274 & SEC_ALLOC) != 0))
275 addend += nlm_fixed_header (abfd)->dataImageSize;
277 if (addend != 0
278 && rel->howto != NULL
279 && rel->howto->rightshift == 0
280 && rel->howto->size == 2
281 && rel->howto->bitsize == 32
282 && rel->howto->bitpos == 0
283 && rel->howto->src_mask == 0xffffffff
284 && rel->howto->dst_mask == 0xffffffff)
286 bfd_vma val;
288 val = bfd_get_32 (abfd, (bfd_byte *) data + rel->address - offset);
289 val += addend;
290 bfd_put_32 (abfd, val, (bfd_byte *) data + rel->address - offset);
291 rel->addend = 0;
294 /* NetWare uses a reloc with pcrel_offset set. We adjust
295 pc_relative relocs accordingly. We are going to change the
296 howto field, so we can only do this if the current one is
297 compatible. We should check special_function here, but at
298 the moment coff-i386 uses a special_function which does not
299 affect what we are doing here. */
300 if (rel->howto != NULL
301 && rel->howto->pc_relative
302 && ! rel->howto->pcrel_offset
303 && rel->howto->rightshift == 0
304 && rel->howto->size == 2
305 && rel->howto->bitsize == 32
306 && rel->howto->bitpos == 0
307 && rel->howto->src_mask == 0xffffffff
308 && rel->howto->dst_mask == 0xffffffff)
310 bfd_vma val;
312 /* When pcrel_offset is not set, it means that the negative
313 of the address of the memory location is stored in the
314 memory location. We must add it back in. */
315 val = bfd_get_32 (abfd, (bfd_byte *) data + rel->address - offset);
316 val += rel->address;
317 bfd_put_32 (abfd, val, (bfd_byte *) data + rel->address - offset);
319 rel->howto = &nlm_i386_pcrel_howto;
323 return TRUE;
326 /* Read a NetWare i386 import record. */
328 static bfd_boolean
329 nlm_i386_read_import (bfd * abfd, nlmNAME (symbol_type) * sym)
331 struct nlm_relent *nlm_relocs; /* Relocation records for symbol. */
332 bfd_size_type rcount; /* Number of relocs. */
333 bfd_byte temp[NLM_TARGET_LONG_SIZE]; /* Temporary 32-bit value. */
334 unsigned char symlength; /* Length of symbol name. */
335 char *name;
337 if (bfd_bread (& symlength, (bfd_size_type) sizeof (symlength), abfd)
338 != sizeof (symlength))
339 return FALSE;
340 sym -> symbol.the_bfd = abfd;
341 name = bfd_alloc (abfd, (bfd_size_type) symlength + 1);
342 if (name == NULL)
343 return FALSE;
344 if (bfd_bread (name, (bfd_size_type) symlength, abfd) != symlength)
345 return FALSE;
346 name[symlength] = '\0';
347 sym -> symbol.name = name;
348 sym -> symbol.flags = 0;
349 sym -> symbol.value = 0;
350 sym -> symbol.section = bfd_und_section_ptr;
351 if (bfd_bread (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
352 return FALSE;
353 rcount = H_GET_32 (abfd, temp);
354 nlm_relocs = bfd_alloc (abfd, rcount * sizeof (struct nlm_relent));
355 if (!nlm_relocs)
356 return FALSE;
357 sym -> relocs = nlm_relocs;
358 sym -> rcnt = 0;
359 while (sym -> rcnt < rcount)
361 asection *section;
363 if (! nlm_i386_read_reloc (abfd, sym, &section, &nlm_relocs -> reloc))
364 return FALSE;
365 nlm_relocs -> section = section;
366 nlm_relocs++;
367 sym -> rcnt++;
369 return TRUE;
372 /* Write out an external reference. */
374 static bfd_boolean
375 nlm_i386_write_external (bfd *abfd,
376 bfd_size_type count,
377 asymbol *sym,
378 struct reloc_and_sec *relocs)
380 unsigned int i;
381 bfd_byte len;
382 unsigned char temp[NLM_TARGET_LONG_SIZE];
384 len = strlen (sym->name);
385 if ((bfd_bwrite (&len, (bfd_size_type) sizeof (bfd_byte), abfd)
386 != sizeof (bfd_byte))
387 || bfd_bwrite (sym->name, (bfd_size_type) len, abfd) != len)
388 return FALSE;
390 bfd_put_32 (abfd, count, temp);
391 if (bfd_bwrite (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp))
392 return FALSE;
394 for (i = 0; i < count; i++)
395 if (! nlm_i386_write_import (abfd, relocs[i].sec, relocs[i].rel))
396 return FALSE;
398 return TRUE;
401 #include "nlmswap.h"
403 static const struct nlm_backend_data nlm32_i386_backend =
405 "NetWare Loadable Module\032",
406 sizeof (Nlm32_i386_External_Fixed_Header),
407 0, /* Optional_prefix_size. */
408 bfd_arch_i386,
410 FALSE,
411 0, /* Backend_object_p. */
412 0, /* Write_prefix_func. */
413 nlm_i386_read_reloc,
414 nlm_i386_mangle_relocs,
415 nlm_i386_read_import,
416 nlm_i386_write_import,
417 0, /* Set_public_section. */
418 0, /* Set_public_offset. */
419 nlm_swap_fixed_header_in,
420 nlm_swap_fixed_header_out,
421 nlm_i386_write_external,
422 0, /* Write_export. */
425 #define TARGET_LITTLE_NAME "nlm32-i386"
426 #define TARGET_LITTLE_SYM nlmNAME (i386_vec)
427 #define TARGET_BACKEND_DATA & nlm32_i386_backend
429 #include "nlm-target.h"