aboutsummaryrefslogtreecommitdiff
path: root/bfd/elf32-powerpc.c
blob: 7950133493dcc86e7ebef5f8cac2f386aab0a74c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
/* PowerPC-specific support for 32-bit ELF
   Copyright 1994 Free Software Foundation, Inc.
   Written by Ian Lance Taylor, Cygnus Support.

This file is part of BFD, the Binary File Descriptor library.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* I wrote this file without the benefit of a PowerPC ELF ABI.  Thus,
   it probably does not correspond to whatever people finally settle
   on.  Ian Taylor.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "libelf.h"

static bfd_reloc_status_type powerpc_elf_toc16_reloc PARAMS ((bfd *abfd,
							      arelent *reloc,
							      asymbol *symbol,
							      PTR data,
							      asection *sec,
							      bfd *output_bfd,
							      char **error));
static bfd_reloc_status_type powerpc_elf_b26_reloc PARAMS ((bfd *abfd,
							    arelent *reloc,
							    asymbol *symbol,
							    PTR data,
							    asection *sec,
							    bfd *output_bfd,
							    char **error));
static const struct reloc_howto_struct *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void powerpc_info_to_howto_rel
  PARAMS ((bfd *abfd, arelent *cache_ptr, Elf32_Internal_Rel *dst));

#define USE_REL

enum reloc_type
{
  R_POWERPC_NONE = 0,
  R_POWERPC_32,
  R_POWERPC_B26,
  R_POWERPC_BA26,
  R_POWERPC_TOC16,
  R_POWERPC_max
};

static reloc_howto_type elf_powerpc_howto_table[] =
{
  /* This relocation does not do anything.  */
  HOWTO (R_POWERPC_NONE,        /* type */                                 
	 0,	                /* rightshift */                           
	 2,	                /* size (0 = byte, 1 = short, 2 = long) */ 
	 32,	                /* bitsize */                   
	 false,	                /* pc_relative */                          
	 0,	                /* bitpos */                               
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc, /* special_function */                     
	 "R_POWERPC_NONE",      /* name */                                 
	 true,	                /* partial_inplace */                      
	 0,		        /* src_mask */                             
	 0,            		/* dst_mask */                             
	 false),                /* pcrel_offset */

  /* Standard 32 bit relocation.  */
  HOWTO (R_POWERPC_32,          /* type */                                 
	 0,	                /* rightshift */                           
	 2,	                /* size (0 = byte, 1 = short, 2 = long) */ 
	 32,	                /* bitsize */                   
	 false,	                /* pc_relative */                          
	 0,	                /* bitpos */                               
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc, /* special_function */                     
	 "R_POWERPC_32",        /* name */                                 
	 true,	                /* partial_inplace */                      
	 0xffffffff,            /* src_mask */                             
	 0xffffffff,            /* dst_mask */                             
	 false),                /* pcrel_offset */

  /* 26 bit relative branch.  */
  HOWTO (R_POWERPC_B26,         /* type */                                 
	 0,	                /* rightshift */                           
	 2,	                /* size (0 = byte, 1 = short, 2 = long) */ 
	 26,	                /* bitsize */                   
	 true,	                /* pc_relative */                          
	 0,	                /* bitpos */                               
	 complain_overflow_signed, /* complain_on_overflow */
	 powerpc_elf_b26_reloc, /* special_function */                     
	 "R_POWERPC_B26",       /* name */                                 
	 true,	                /* partial_inplace */                      
	 0x3fffffc,	        /* src_mask */                             
	 0x3fffffc,        	/* dst_mask */                             
	 false),                /* pcrel_offset */

  /* 26 bit absolute branch.  */
  HOWTO (R_POWERPC_BA26,        /* type */                                 
	 0,	                /* rightshift */                           
	 2,	                /* size (0 = byte, 1 = short, 2 = long) */ 
	 26,	                /* bitsize */                   
	 false,	                /* pc_relative */                          
	 0,	                /* bitpos */                               
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc, /* special_function */                     
	 "R_POWERPC_BA26",      /* name */                                 
	 true,	                /* partial_inplace */                      
	 0x3fffffc,	        /* src_mask */                             
	 0x3fffffc,        	/* dst_mask */                             
	 false),                /* pcrel_offset */
  
  /* 16 bit reference to TOC section.  */
  HOWTO (R_POWERPC_TOC16,       /* type */                                 
	 0,	                /* rightshift */                           
	 1,	                /* size (0 = byte, 1 = short, 2 = long) */ 
	 16,	                /* bitsize */                   
	 false,	                /* pc_relative */                          
	 0,	                /* bitpos */                               
	 complain_overflow_signed, /* complain_on_overflow */
	 powerpc_elf_toc16_reloc, /* special_function */                     
	 "R_POWERPC_TOC16",     /* name */                                 
	 true,	                /* partial_inplace */                      
	 0xffff,	        /* src_mask */                             
	 0xffff,        	/* dst_mask */                             
	 false),                /* pcrel_offset */
};

/* Handle the TOC16 reloc.  We want to use the offset within the .toc
   section, not the actual VMA.  */

static bfd_reloc_status_type
powerpc_elf_toc16_reloc (abfd,
			 reloc_entry,
			 symbol,
			 data,
			 input_section,
			 output_bfd,
			 error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  asection *sec;

  /* Simply adjust the reloc addend by the negative of the VMA of the
     .toc section.  */
  sec = bfd_get_section (*reloc_entry->sym_ptr_ptr);
  if (sec == &bfd_und_section)
    return bfd_reloc_continue;
  BFD_ASSERT (strcmp (bfd_get_section_name (abfd, sec), ".toc") == 0);
  reloc_entry->addend -= sec->output_section->vma;
  return bfd_reloc_continue;
}

/* Handle a branch.  If the next instruction is the special
   instruction "cror 31,31,31", and this branch is to a stub routine
   we have created, we must change the cror instruction into an
   instruction which reloads the TOC register.  We can detect a stub
   routine because it is in a BFD named "linker stubs".  FIXME: What a
   hack.  */

static bfd_reloc_status_type
powerpc_elf_b26_reloc (abfd,
		       reloc_entry,
		       symbol,
		       data,
		       input_section,
		       output_bfd,
		       error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  if (bfd_get_section (symbol) != &bfd_und_section
      && (strcmp (bfd_get_section (symbol)->owner->filename, "linker stubs")
	  == 0))
    {
      bfd_vma val;

      /* This symbol is a stub created by the linker.  */
      val = bfd_get_32 (abfd, (bfd_byte *) data + reloc_entry->address + 4);
      if (val == 0x4ffffb82)			/* cror 31,31,31 */
	bfd_put_32 (abfd, (bfd_vma) 0x80410014,	/* l r2,20(r1) */
		    (bfd_byte *) data + reloc_entry->address + 4);
    }

  if (output_bfd != (bfd *) NULL
      && bfd_get_section (symbol) == &bfd_und_section)
    {
      bfd_size_type address;

      /* If we are generating relocateable output, and the symbol is
	 undefined, we just want to adjust the reloc by the amount the
	 section moved.  */
      address = reloc_entry->address;
      reloc_entry->address += input_section->output_offset;
      return _bfd_relocate_contents (reloc_entry->howto, abfd,
				     - input_section->output_offset,
				     (bfd_byte *) data + address);
    }

  /* Otherwise, let bfd_perform_relocation handle it.  */
  return bfd_reloc_continue;
}

/* Map BFD reloc types to PowerPC ELF reloc types.  */

struct powerpc_reloc_map
{
  unsigned char bfd_reloc_val;
  unsigned char elf_reloc_val;
};

static const struct powerpc_reloc_map powerpc_reloc_map[] =
{
  { BFD_RELOC_NONE, R_POWERPC_NONE, },
  { BFD_RELOC_32, R_POWERPC_32 },
  { BFD_RELOC_CTOR, R_POWERPC_32 },
  { BFD_RELOC_PPC_B26, R_POWERPC_B26 },
  { BFD_RELOC_PPC_BA26, R_POWERPC_BA26 },
  { BFD_RELOC_PPC_TOC16, R_POWERPC_TOC16 }
};

static const struct reloc_howto_struct *
bfd_elf32_bfd_reloc_type_lookup (abfd, code)
     bfd *abfd;
     bfd_reloc_code_real_type code;
{
  int i;

  for (i = 0;
       i < sizeof (powerpc_reloc_map) / sizeof (struct powerpc_reloc_map);
       i++)
    {
      if (powerpc_reloc_map[i].bfd_reloc_val == code)
	return &elf_powerpc_howto_table[powerpc_reloc_map[i].elf_reloc_val];
    }

  return NULL;
}

/* Set the howto pointer for a PowerPC ELF reloc.  */

static void
powerpc_info_to_howto_rel (abfd, cache_ptr, dst)
     bfd *abfd;
     arelent *cache_ptr;
     Elf32_Internal_Rel *dst;
{
  BFD_ASSERT (ELF32_R_TYPE (dst->r_info) < (unsigned int) R_POWERPC_max);
  cache_ptr->howto = &elf_powerpc_howto_table[ELF32_R_TYPE(dst->r_info)];
}

#define TARGET_BIG_SYM		bfd_elf32_powerpc_vec
#define TARGET_BIG_NAME		"elf32-powerpc"
#define ELF_ARCH		bfd_arch_powerpc
#define ELF_MACHINE_CODE	EM_CYGNUS_POWERPC
#define ELF_MAXPAGESIZE		0x10000
#define elf_info_to_howto	0
#define elf_info_to_howto_rel	powerpc_info_to_howto_rel

#include "elf32-target.h"