xref: /openbsd/gnu/usr.bin/binutils/bfd/elf32-arc.c (revision d89ec533)
1 /* ARC-specific support for 32-bit ELF
2    Copyright 1994, 1995, 1997, 1999, 2001, 2002
3    Free Software Foundation, Inc.
4    Contributed by Doug Evans (dje@cygnus.com).
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
21 
22 #include "bfd.h"
23 #include "sysdep.h"
24 #include "libbfd.h"
25 #include "elf-bfd.h"
26 #include "elf/arc.h"
27 #include "libiberty.h"
28 
29 static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
30   PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
31 static void arc_info_to_howto_rel
32   PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
33 static bfd_boolean arc_elf_object_p
34   PARAMS ((bfd *));
35 static void arc_elf_final_write_processing
36   PARAMS ((bfd *, bfd_boolean));
37 static bfd_reloc_status_type arc_elf_b22_pcrel
38   PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
39 
40 /* Try to minimize the amount of space occupied by relocation tables
41    on the ROM (not that the ROM won't be swamped by other ELF overhead).  */
42 
43 #define USE_REL	1
44 
45 static reloc_howto_type elf_arc_howto_table[] =
46 {
47   /* This reloc does nothing.  */
48   HOWTO (R_ARC_NONE,		/* type  */
49 	 0,			/* rightshift  */
50 	 2,			/* size (0 = byte, 1 = short, 2 = long)  */
51 	 32,			/* bitsize  */
52 	 FALSE,			/* pc_relative  */
53 	 0,			/* bitpos  */
54 	 complain_overflow_bitfield, /* complain_on_overflow  */
55 	 bfd_elf_generic_reloc,	/* special_function  */
56 	 "R_ARC_NONE",		/* name  */
57 	 TRUE,			/* partial_inplace  */
58 	 0,			/* src_mask  */
59 	 0,			/* dst_mask  */
60 	 FALSE),		/* pcrel_offset  */
61 
62   /* A standard 32 bit relocation.  */
63   HOWTO (R_ARC_32,		/* type  */
64 	 0,			/* rightshift  */
65 	 2,			/* size (0 = byte, 1 = short, 2 = long)  */
66 	 32,			/* bitsize  */
67 	 FALSE,			/* pc_relative  */
68 	 0,			/* bitpos  */
69 	 complain_overflow_bitfield, /* complain_on_overflow  */
70 	 bfd_elf_generic_reloc,	/* special_function  */
71 	 "R_ARC_32",		/* name  */
72 	 TRUE,			/* partial_inplace  */
73 	 0xffffffff,		/* src_mask  */
74 	 0xffffffff,		/* dst_mask  */
75 	 FALSE),		/* pcrel_offset  */
76 
77   /* A 26 bit absolute branch, right shifted by 2.  */
78   HOWTO (R_ARC_B26,		/* type  */
79 	 2,			/* rightshift  */
80 	 2,			/* size (0 = byte, 1 = short, 2 = long)  */
81 	 26,			/* bitsize  */
82 	 FALSE,			/* pc_relative  */
83 	 0,			/* bitpos  */
84 	 complain_overflow_bitfield, /* complain_on_overflow  */
85 	 bfd_elf_generic_reloc,	/* special_function  */
86 	 "R_ARC_B26",		/* name  */
87 	 TRUE,			/* partial_inplace  */
88 	 0x00ffffff,		/* src_mask  */
89 	 0x00ffffff,		/* dst_mask  */
90 	 FALSE),		/* pcrel_offset  */
91 
92   /* A relative 22 bit branch; bits 21-2 are stored in bits 26-7.  */
93   HOWTO (R_ARC_B22_PCREL,	/* type  */
94 	 2,			/* rightshift  */
95 	 2,			/* size (0 = byte, 1 = short, 2 = long)  */
96 	 22,			/* bitsize  */
97 	 TRUE,			/* pc_relative  */
98 	 7,			/* bitpos  */
99 	 complain_overflow_signed, /* complain_on_overflow  */
100 	 arc_elf_b22_pcrel,	/* special_function  */
101 	 "R_ARC_B22_PCREL",	/* name  */
102 	 TRUE,			/* partial_inplace  */
103 	 0x07ffff80,		/* src_mask  */
104 	 0x07ffff80,		/* dst_mask  */
105 	 FALSE),		/* pcrel_offset  */
106 };
107 
108 /* Map BFD reloc types to ARC ELF reloc types.  */
109 
110 struct arc_reloc_map
111 {
112   bfd_reloc_code_real_type bfd_reloc_val;
113   unsigned char elf_reloc_val;
114 };
115 
116 static const struct arc_reloc_map arc_reloc_map[] =
117 {
118   { BFD_RELOC_NONE, R_ARC_NONE, },
119   { BFD_RELOC_32, R_ARC_32 },
120   { BFD_RELOC_CTOR, R_ARC_32 },
121   { BFD_RELOC_ARC_B26, R_ARC_B26 },
122   { BFD_RELOC_ARC_B22_PCREL, R_ARC_B22_PCREL },
123 };
124 
125 static reloc_howto_type *
126 bfd_elf32_bfd_reloc_type_lookup (abfd, code)
127      bfd *abfd ATTRIBUTE_UNUSED;
128      bfd_reloc_code_real_type code;
129 {
130   unsigned int i;
131 
132   for (i = ARRAY_SIZE (arc_reloc_map); i--;)
133     if (arc_reloc_map[i].bfd_reloc_val == code)
134       return elf_arc_howto_table + arc_reloc_map[i].elf_reloc_val;
135 
136   return NULL;
137 }
138 
139 /* Set the howto pointer for an ARC ELF reloc.  */
140 
141 static void
142 arc_info_to_howto_rel (abfd, cache_ptr, dst)
143      bfd *abfd ATTRIBUTE_UNUSED;
144      arelent *cache_ptr;
145      Elf_Internal_Rela *dst;
146 {
147   unsigned int r_type;
148 
149   r_type = ELF32_R_TYPE (dst->r_info);
150   BFD_ASSERT (r_type < (unsigned int) R_ARC_max);
151   cache_ptr->howto = &elf_arc_howto_table[r_type];
152 }
153 
154 /* Set the right machine number for an ARC ELF file.  */
155 
156 static bfd_boolean
157 arc_elf_object_p (abfd)
158      bfd *abfd;
159 {
160   unsigned int mach = bfd_mach_arc_6;
161 
162   if (elf_elfheader(abfd)->e_machine == EM_ARC)
163     {
164       unsigned long arch = elf_elfheader (abfd)->e_flags & EF_ARC_MACH;
165 
166       switch (arch)
167 	{
168 	case E_ARC_MACH_ARC5:
169 	  mach = bfd_mach_arc_5;
170 	  break;
171 	default:
172 	case E_ARC_MACH_ARC6:
173 	  mach = bfd_mach_arc_6;
174 	  break;
175 	case E_ARC_MACH_ARC7:
176 	  mach = bfd_mach_arc_7;
177 	  break;
178 	case E_ARC_MACH_ARC8:
179 	  mach = bfd_mach_arc_8;
180 	  break;
181 	}
182     }
183   return bfd_default_set_arch_mach (abfd, bfd_arch_arc, mach);
184 }
185 
186 /* The final processing done just before writing out an ARC ELF object file.
187    This gets the ARC architecture right based on the machine number.  */
188 
189 static void
190 arc_elf_final_write_processing (abfd, linker)
191      bfd *abfd;
192      bfd_boolean linker ATTRIBUTE_UNUSED;
193 {
194   unsigned long val;
195 
196   switch (bfd_get_mach (abfd))
197     {
198     case bfd_mach_arc_5:
199       val = E_ARC_MACH_ARC5;
200       break;
201     default:
202     case bfd_mach_arc_6:
203       val = E_ARC_MACH_ARC6;
204       break;
205     case bfd_mach_arc_7:
206       val = E_ARC_MACH_ARC7;
207       break;
208     case bfd_mach_arc_8:
209       val = E_ARC_MACH_ARC8;
210       break;
211     }
212   elf_elfheader (abfd)->e_flags &=~ EF_ARC_MACH;
213   elf_elfheader (abfd)->e_flags |= val;
214 }
215 
216 bfd_reloc_status_type
217 arc_elf_b22_pcrel (abfd, reloc_entry, symbol, data, input_section,
218 		   output_bfd, error_message)
219      bfd * abfd;
220      arelent * reloc_entry;
221      asymbol * symbol;
222      PTR data;
223      asection * input_section;
224      bfd * output_bfd;
225      char ** error_message;
226 {
227   /* If linking, back up the final symbol address by the address of the
228      reloc.  This cannot be accomplished by setting the pcrel_offset
229      field to TRUE, as bfd_install_relocation will detect this and refuse
230      to install the offset in the first place, but bfd_perform_relocation
231      will still insist on removing it.  */
232   if (output_bfd == (bfd *) NULL)
233     reloc_entry->addend -= reloc_entry->address;
234 
235   /* Fall through to the default elf reloc handler.  */
236   return bfd_elf_generic_reloc (abfd, reloc_entry, symbol, data,
237 				input_section, output_bfd, error_message);
238 }
239 
240 #define TARGET_LITTLE_SYM bfd_elf32_littlearc_vec
241 #define TARGET_LITTLE_NAME "elf32-littlearc"
242 #define TARGET_BIG_SYM bfd_elf32_bigarc_vec
243 #define TARGET_BIG_NAME	"elf32-bigarc"
244 #define ELF_ARCH bfd_arch_arc
245 #define ELF_MACHINE_CODE EM_ARC
246 #define ELF_MAXPAGESIZE	0x1000
247 
248 #define elf_info_to_howto 0
249 #define elf_info_to_howto_rel arc_info_to_howto_rel
250 #define elf_backend_object_p arc_elf_object_p
251 #define elf_backend_final_write_processing arc_elf_final_write_processing
252 
253 #include "elf32-target.h"
254