1 /* BFD support for the ns32k architecture.
2 Copyright (C) 1990-2015 Free Software Foundation, Inc.
3 Almost totally rewritten by Ian Dall from initial work
6 This file is part of BFD, the Binary File Descriptor library.
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 3 of the License, or
11 (at your option) any later version.
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.
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,
21 MA 02110-1301, USA. */
28 #define N(machine, printable, d, next) \
29 { 32, 32, 8, bfd_arch_ns32k, machine, "ns32k",printable,3,d, \
30 bfd_default_compatible,bfd_default_scan,bfd_arch_default_fill,next, }
32 static const bfd_arch_info_type arch_info_struct[] =
34 N(32532,"ns32k:32532",TRUE, 0), /* The word ns32k will match this too. */
37 const bfd_arch_info_type bfd_ns32k_arch =
38 N(32032,"ns32k:32032",FALSE, &arch_info_struct[0]);
41 _bfd_ns32k_get_displacement (bfd_byte *buffer, int size)
48 value = ((*buffer & 0x7f) ^ 0x40) - 0x40;
52 value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
53 value = (value << 8) | (0xff & *buffer);
57 value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
58 value = (value << 8) | (0xff & *buffer++);
59 value = (value << 8) | (0xff & *buffer++);
60 value = (value << 8) | (0xff & *buffer);
72 _bfd_ns32k_put_displacement (bfd_vma value, bfd_byte *buffer, int size)
84 *buffer++ = (value >> 8);
89 value |= (bfd_vma) 0xc0000000;
90 *buffer++ = (value >> 24);
91 *buffer++ = (value >> 16);
92 *buffer++ = (value >> 8);
100 _bfd_ns32k_get_immediate (bfd_byte *buffer, int size)
107 value = (value << 8) | (*buffer++ & 0xff);
108 value = (value << 8) | (*buffer++ & 0xff);
110 value = (value << 8) | (*buffer++ & 0xff);
112 value = (value << 8) | (*buffer++ & 0xff);
121 _bfd_ns32k_put_immediate (bfd_vma value, bfd_byte *buffer, int size)
127 *buffer-- = (value & 0xff); value >>= 8;
128 *buffer-- = (value & 0xff); value >>= 8;
130 *buffer-- = (value & 0xff); value >>= 8;
132 *buffer-- = (value & 0xff); value >>= 8;
136 /* This is just like the standard perform_relocation except we
137 use get_data and put_data which know about the ns32k storage
138 methods. This is probably a lot more complicated than it
141 static bfd_reloc_status_type
142 do_ns32k_reloc (bfd * abfd,
143 arelent * reloc_entry,
144 struct bfd_symbol * symbol,
146 asection * input_section,
148 char ** error_message ATTRIBUTE_UNUSED,
149 bfd_vma (* get_data) (bfd_byte *, int),
150 void (* put_data) (bfd_vma, bfd_byte *, int))
154 bfd_reloc_status_type flag = bfd_reloc_ok;
155 bfd_size_type addr = reloc_entry->address;
156 bfd_vma output_base = 0;
157 reloc_howto_type *howto = reloc_entry->howto;
158 asection *reloc_target_output_section;
161 if (bfd_is_abs_section (symbol->section)
162 && output_bfd != (bfd *) NULL)
164 reloc_entry->address += input_section->output_offset;
168 /* If we are not producing relocatable output, return an error if
169 the symbol is not defined. An undefined weak symbol is
170 considered to have a value of zero (SVR4 ABI, p. 4-27). */
171 if (bfd_is_und_section (symbol->section)
172 && (symbol->flags & BSF_WEAK) == 0
173 && output_bfd == (bfd *) NULL)
174 flag = bfd_reloc_undefined;
176 /* Is the address of the relocation really within the section? */
177 if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))
178 return bfd_reloc_outofrange;
180 /* Work out which section the relocation is targeted at and the
181 initial relocation command value. */
183 /* Get symbol value. (Common symbols are special.) */
184 if (bfd_is_com_section (symbol->section))
187 relocation = symbol->value;
189 reloc_target_output_section = symbol->section->output_section;
191 /* Convert input-section-relative symbol value to absolute. */
192 if (output_bfd != NULL && ! howto->partial_inplace)
195 output_base = reloc_target_output_section->vma;
197 relocation += output_base + symbol->section->output_offset;
199 /* Add in supplied addend. */
200 relocation += reloc_entry->addend;
202 /* Here the variable relocation holds the final address of the
203 symbol we are relocating against, plus any addend. */
205 if (howto->pc_relative)
207 /* This is a PC relative relocation. We want to set RELOCATION
208 to the distance between the address of the symbol and the
209 location. RELOCATION is already the address of the symbol.
211 We start by subtracting the address of the section containing
214 If pcrel_offset is set, we must further subtract the position
215 of the location within the section. Some targets arrange for
216 the addend to be the negative of the position of the location
217 within the section; for example, i386-aout does this. For
218 i386-aout, pcrel_offset is FALSE. Some other targets do not
219 include the position of the location; for example, m88kbcs,
220 or ELF. For those targets, pcrel_offset is TRUE.
222 If we are producing relocatable output, then we must ensure
223 that this reloc will be correctly computed when the final
224 relocation is done. If pcrel_offset is FALSE we want to wind
225 up with the negative of the location within the section,
226 which means we must adjust the existing addend by the change
227 in the location within the section. If pcrel_offset is TRUE
228 we do not want to adjust the existing addend at all.
230 FIXME: This seems logical to me, but for the case of
231 producing relocatable output it is not what the code
232 actually does. I don't want to change it, because it seems
233 far too likely that something will break. */
235 input_section->output_section->vma + input_section->output_offset;
237 if (howto->pcrel_offset)
238 relocation -= reloc_entry->address;
241 if (output_bfd != (bfd *) NULL)
243 if (! howto->partial_inplace)
245 /* This is a partial relocation, and we want to apply the relocation
246 to the reloc entry rather than the raw data. Modify the reloc
247 inplace to reflect what we now know. */
248 reloc_entry->addend = relocation;
249 reloc_entry->address += input_section->output_offset;
254 /* This is a partial relocation, but inplace, so modify the
257 If we've relocated with a symbol with a section, change
258 into a ref to the section belonging to the symbol. */
260 reloc_entry->address += input_section->output_offset;
263 if (abfd->xvec->flavour == bfd_target_coff_flavour)
265 /* For m68k-coff, the addend was being subtracted twice during
266 relocation with -r. Removing the line below this comment
267 fixes that problem; see PR 2953.
269 However, Ian wrote the following, regarding removing the line
270 below, which explains why it is still enabled: --djm
272 If you put a patch like that into BFD you need to check all
273 the COFF linkers. I am fairly certain that patch will break
274 coff-i386 (e.g., SCO); see coff_i386_reloc in coff-i386.c
275 where I worked around the problem in a different way. There
276 may very well be a reason that the code works as it does.
278 Hmmm. The first obvious point is that bfd_perform_relocation
279 should not have any tests that depend upon the flavour. It's
280 seem like entirely the wrong place for such a thing. The
281 second obvious point is that the current code ignores the
282 reloc addend when producing relocatable output for COFF.
283 That's peculiar. In fact, I really have no idea what the
284 point of the line you want to remove is.
286 A typical COFF reloc subtracts the old value of the symbol
287 and adds in the new value to the location in the object file
288 (if it's a pc relative reloc it adds the difference between
289 the symbol value and the location). When relocating we need
290 to preserve that property.
292 BFD handles this by setting the addend to the negative of the
293 old value of the symbol. Unfortunately it handles common
294 symbols in a non-standard way (it doesn't subtract the old
295 value) but that's a different story (we can't change it
296 without losing backward compatibility with old object files)
297 (coff-i386 does subtract the old value, to be compatible with
298 existing coff-i386 targets, like SCO).
300 So everything works fine when not producing relocatable
301 output. When we are producing relocatable output, logically
302 we should do exactly what we do when not producing
303 relocatable output. Therefore, your patch is correct. In
304 fact, it should probably always just set reloc_entry->addend
305 to 0 for all cases, since it is, in fact, going to add the
306 value into the object file. This won't hurt the COFF code,
307 which doesn't use the addend; I'm not sure what it will do
308 to other formats (the thing to check for would be whether
309 any formats both use the addend and set partial_inplace).
311 When I wanted to make coff-i386 produce relocatable output,
312 I ran into the problem that you are running into: I wanted
313 to remove that line. Rather than risk it, I made the
314 coff-i386 relocs use a special function; it's coff_i386_reloc
315 in coff-i386.c. The function specifically adds the addend
316 field into the object file, knowing that bfd_perform_relocation
317 is not going to. If you remove that line, then coff-i386.c
318 will wind up adding the addend field in twice. It's trivial
319 to fix; it just needs to be done.
321 The problem with removing the line is just that it may break
322 some working code. With BFD it's hard to be sure of anything.
323 The right way to deal with this is simply to build and test at
324 least all the supported COFF targets. It should be
325 straightforward if time and disk space consuming. For each
328 2) generate some executable, and link it using -r (I would
329 probably use paranoia.o and link against newlib/libc.a,
330 which for all the supported targets would be available in
331 /usr/cygnus/progressive/H-host/target/lib/libc.a).
332 3) make the change to reloc.c
333 4) rebuild the linker
335 6) if the resulting object files are the same, you have at
336 least made it no worse
337 7) if they are different you have to figure out which
339 relocation -= reloc_entry->addend;
340 reloc_entry->addend = 0;
344 reloc_entry->addend = relocation;
350 reloc_entry->addend = 0;
353 /* FIXME: This overflow checking is incomplete, because the value
354 might have overflowed before we get here. For a correct check we
355 need to compute the value in a size larger than bitsize, but we
356 can't reasonably do that for a reloc the same size as a host
358 FIXME: We should also do overflow checking on the result after
359 adding in the value contained in the object file. */
360 if (howto->complain_on_overflow != complain_overflow_dont)
364 /* Get the value that will be used for the relocation, but
365 starting at bit position zero. */
366 if (howto->rightshift > howto->bitpos)
367 check = relocation >> (howto->rightshift - howto->bitpos);
369 check = relocation << (howto->bitpos - howto->rightshift);
370 switch (howto->complain_on_overflow)
372 case complain_overflow_signed:
374 /* Assumes two's complement. */
375 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
376 bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
378 /* The above right shift is incorrect for a signed value.
379 Fix it up by forcing on the upper bits. */
380 if (howto->rightshift > howto->bitpos
381 && (bfd_signed_vma) relocation < 0)
382 check |= ((bfd_vma) - 1
384 >> (howto->rightshift - howto->bitpos)));
385 if ((bfd_signed_vma) check > reloc_signed_max
386 || (bfd_signed_vma) check < reloc_signed_min)
387 flag = bfd_reloc_overflow;
390 case complain_overflow_unsigned:
392 /* Assumes two's complement. This expression avoids
393 overflow if howto->bitsize is the number of bits in
395 bfd_vma reloc_unsigned_max =
396 (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
398 if ((bfd_vma) check > reloc_unsigned_max)
399 flag = bfd_reloc_overflow;
402 case complain_overflow_bitfield:
404 /* Assumes two's complement. This expression avoids
405 overflow if howto->bitsize is the number of bits in
407 bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
409 if (((bfd_vma) check & ~reloc_bits) != 0
410 && (((bfd_vma) check & ~reloc_bits)
411 != (-(bfd_vma) 1 & ~reloc_bits)))
413 /* The above right shift is incorrect for a signed
414 value. See if turning on the upper bits fixes the
416 if (howto->rightshift > howto->bitpos
417 && (bfd_signed_vma) relocation < 0)
419 check |= ((bfd_vma) - 1
421 >> (howto->rightshift - howto->bitpos)));
422 if (((bfd_vma) check & ~reloc_bits)
423 != (-(bfd_vma) 1 & ~reloc_bits))
424 flag = bfd_reloc_overflow;
427 flag = bfd_reloc_overflow;
436 /* Either we are relocating all the way, or we don't want to apply
437 the relocation to the reloc entry (probably because there isn't
438 any room in the output format to describe addends to relocs). */
440 /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
441 (OSF version 1.3, compiler version 3.11). It miscompiles the
455 x <<= (unsigned long) s.i0;
459 printf ("succeeded (%lx)\n", x);
463 relocation >>= (bfd_vma) howto->rightshift;
465 /* Shift everything up to where it's going to be used. */
466 relocation <<= (bfd_vma) howto->bitpos;
468 /* Wait for the day when all have the mask in them. */
471 i instruction to be left alone
472 o offset within instruction
473 r relocation offset to apply
482 i i i i i o o o o o from bfd_get<size>
483 and S S S S S to get the size offset we want
484 + r r r r r r r r r r to get the final value to place
485 and D D D D D to chop to right size
486 -----------------------
489 ... i i i i i o o o o o from bfd_get<size>
490 and N N N N N get instruction
491 -----------------------
497 -----------------------
498 R R R R R R R R R R put into bfd_put<size>. */
501 x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
503 location = (bfd_byte *) data + addr;
508 bfd_vma x = get_data (location, 1);
510 put_data ((bfd_vma) x, location, 1);
517 bfd_vma x = get_data (location, 2);
519 put_data ((bfd_vma) x, location, 2);
525 bfd_vma x = get_data (location, 4);
527 put_data ((bfd_vma) x, location, 4);
532 bfd_vma x = get_data (location, 4);
533 relocation = -relocation;
535 put_data ((bfd_vma) x, location, 4);
547 bfd_vma x = get_data (location, 8);
549 put_data (x, location, 8);
556 return bfd_reloc_other;
558 if ((howto->complain_on_overflow != complain_overflow_dont) && overflow)
559 return bfd_reloc_overflow;
564 /* Relocate a given location using a given value and howto. */
566 bfd_reloc_status_type
567 _bfd_do_ns32k_reloc_contents (reloc_howto_type *howto,
568 bfd *input_bfd ATTRIBUTE_UNUSED,
571 bfd_vma (*get_data) (bfd_byte *, int),
572 void (*put_data) (bfd_vma, bfd_byte *, int))
576 bfd_boolean overflow;
578 /* If the size is negative, negate RELOCATION. This isn't very
581 relocation = -relocation;
583 /* Get the value we are going to relocate. */
584 size = bfd_get_reloc_size (howto);
597 x = get_data (location, size);
601 /* Check for overflow. FIXME: We may drop bits during the addition
602 which we don't check for. We must either check at every single
603 operation, which would be tedious, or we must do the computations
604 in a type larger than bfd_vma, which would be inefficient. */
606 if (howto->complain_on_overflow != complain_overflow_dont)
609 bfd_signed_vma signed_check;
611 bfd_signed_vma signed_add;
613 if (howto->rightshift == 0)
616 signed_check = (bfd_signed_vma) relocation;
620 /* Drop unwanted bits from the value we are relocating to. */
621 check = relocation >> howto->rightshift;
623 /* If this is a signed value, the rightshift just dropped
624 leading 1 bits (assuming twos complement). */
625 if ((bfd_signed_vma) relocation >= 0)
626 signed_check = check;
628 signed_check = (check
630 & ~((bfd_vma) - 1 >> howto->rightshift)));
633 /* Get the value from the object file. */
634 add = x & howto->src_mask;
636 /* Get the value from the object file with an appropriate sign.
637 The expression involving howto->src_mask isolates the upper
638 bit of src_mask. If that bit is set in the value we are
639 adding, it is negative, and we subtract out that number times
640 two. If src_mask includes the highest possible bit, then we
641 can not get the upper bit, but that does not matter since
642 signed_add needs no adjustment to become negative in that
645 if ((add & (((~howto->src_mask) >> 1) & howto->src_mask)) != 0)
646 signed_add -= (((~howto->src_mask) >> 1) & howto->src_mask) << 1;
648 /* Add the value from the object file, shifted so that it is a
650 if (howto->bitpos == 0)
653 signed_check += signed_add;
657 check += add >> howto->bitpos;
659 /* For the signed case we use ADD, rather than SIGNED_ADD,
660 to avoid warnings from SVR4 cc. This is OK since we
661 explicitly handle the sign bits. */
663 signed_check += add >> howto->bitpos;
665 signed_check += ((add >> howto->bitpos)
667 & ~((bfd_vma) - 1 >> howto->bitpos)));
670 switch (howto->complain_on_overflow)
672 case complain_overflow_signed:
674 /* Assumes two's complement. */
675 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
676 bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
678 if (signed_check > reloc_signed_max
679 || signed_check < reloc_signed_min)
683 case complain_overflow_unsigned:
685 /* Assumes two's complement. This expression avoids
686 overflow if howto->bitsize is the number of bits in
688 bfd_vma reloc_unsigned_max =
689 (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
691 if (check > reloc_unsigned_max)
695 case complain_overflow_bitfield:
697 /* Assumes two's complement. This expression avoids
698 overflow if howto->bitsize is the number of bits in
700 bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
702 if ((check & ~reloc_bits) != 0
703 && (((bfd_vma) signed_check & ~reloc_bits)
704 != (-(bfd_vma) 1 & ~reloc_bits)))
713 /* Put RELOCATION in the right bits. */
714 relocation >>= (bfd_vma) howto->rightshift;
715 relocation <<= (bfd_vma) howto->bitpos;
717 /* Add RELOCATION to the right bits of X. */
718 x = ((x & ~howto->dst_mask)
719 | (((x & howto->src_mask) + relocation) & howto->dst_mask));
721 /* Put the relocated value back in the object file. */
733 put_data (x, location, size);
737 return overflow ? bfd_reloc_overflow : bfd_reloc_ok;
740 bfd_reloc_status_type
741 _bfd_ns32k_reloc_disp (bfd *abfd,
742 arelent *reloc_entry,
743 struct bfd_symbol *symbol,
745 asection *input_section,
747 char **error_message)
749 return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
750 output_bfd, error_message,
751 _bfd_ns32k_get_displacement,
752 _bfd_ns32k_put_displacement);
755 bfd_reloc_status_type
756 _bfd_ns32k_reloc_imm (bfd *abfd,
757 arelent *reloc_entry,
758 struct bfd_symbol *symbol,
760 asection *input_section,
762 char **error_message)
764 return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
765 output_bfd, error_message, _bfd_ns32k_get_immediate,
766 _bfd_ns32k_put_immediate);
769 bfd_reloc_status_type
770 _bfd_ns32k_final_link_relocate (reloc_howto_type *howto,
772 asection *input_section,
780 /* Sanity check the address. */
781 if (address > bfd_get_section_limit (input_bfd, input_section))
782 return bfd_reloc_outofrange;
784 /* This function assumes that we are dealing with a basic relocation
785 against a symbol. We want to compute the value of the symbol to
786 relocate to. This is just VALUE, the value of the symbol, plus
787 ADDEND, any addend associated with the reloc. */
788 relocation = value + addend;
790 /* If the relocation is PC relative, we want to set RELOCATION to
791 the distance between the symbol (currently in RELOCATION) and the
792 location we are relocating. Some targets (e.g., i386-aout)
793 arrange for the contents of the section to be the negative of the
794 offset of the location within the section; for such targets
795 pcrel_offset is FALSE. Other targets (e.g., m88kbcs or ELF)
796 simply leave the contents of the section as zero; for such
797 targets pcrel_offset is TRUE. If pcrel_offset is FALSE we do not
798 need to subtract out the offset of the location within the
799 section (which is just ADDRESS). */
800 if (howto->pc_relative)
802 relocation -= (input_section->output_section->vma
803 + input_section->output_offset);
804 if (howto->pcrel_offset)
805 relocation -= address;
808 return _bfd_ns32k_relocate_contents (howto, input_bfd, relocation,