elf32-arc.c revision 60484 
1/* ARC-specific support for 32-bit ELF
2   Copyright (C) 1994, 1995, 1997, 1999 Free Software Foundation, Inc.
3   Contributed by Doug Evans (dje@cygnus.com).
4
5This file is part of BFD, the Binary File Descriptor library.
6
7This program is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2 of the License, or
10(at your option) any later version.
11
12This program is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with this program; if not, write to the Free Software
19Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
20
21#include "bfd.h"
22#include "sysdep.h"
23#include "libbfd.h"
24#include "elf-bfd.h"
25#include "elf/arc.h"
26
27static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
28 PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
29static void arc_info_to_howto_rel
30  PARAMS ((bfd *, arelent *, Elf32_Internal_Rel *));
31static boolean arc_elf_object_p PARAMS ((bfd *));
32static void arc_elf_final_write_processing PARAMS ((bfd *, boolean));
33
34/* Try to minimize the amount of space occupied by relocation tables
35   on the ROM (not that the ROM won't be swamped by other ELF overhead).  */
36#define USE_REL
37
38static reloc_howto_type elf_arc_howto_table[] =
39{
40  /* This reloc does nothing.  */
41  HOWTO (R_ARC_NONE,		/* type */
42	 0,			/* rightshift */
43	 2,			/* size (0 = byte, 1 = short, 2 = long) */
44	 32,			/* bitsize */
45	 false,			/* pc_relative */
46	 0,			/* bitpos */
47	 complain_overflow_bitfield, /* complain_on_overflow */
48	 bfd_elf_generic_reloc,	/* special_function */
49	 "R_ARC_NONE",		/* name */
50	 false,			/* partial_inplace */
51	 0,			/* src_mask */
52	 0,			/* dst_mask */
53	 false),		/* pcrel_offset */
54
55  /* A standard 32 bit relocation.  */
56  HOWTO (R_ARC_32,		/* type */
57	 0,	                /* rightshift */
58	 2,	                /* size (0 = byte, 1 = short, 2 = long) */
59	 32,	                /* bitsize */
60	 false,	                /* pc_relative */
61	 0,	                /* bitpos */
62	 complain_overflow_bitfield, /* complain_on_overflow */
63	 bfd_elf_generic_reloc, /* special_function */
64	 "R_ARC_32",		/* name */
65	 false,	                /* partial_inplace */
66	 0xffffffff,	        /* src_mask */
67	 0xffffffff,   		/* dst_mask */
68	 false),                /* pcrel_offset */
69
70  /* A 26 bit absolute branch, right shifted by 2.  */
71  HOWTO (R_ARC_B26,		/* type */
72	 2,			/* rightshift */
73	 2,			/* size (0 = byte, 1 = short, 2 = long) */
74	 26,			/* bitsize */
75	 false,			/* pc_relative */
76	 0,			/* bitpos */
77	 complain_overflow_bitfield, /* complain_on_overflow */
78	 bfd_elf_generic_reloc,	/* special_function */
79	 "R_ARC_B26",		/* name */
80	 false,			/* partial_inplace */
81	 0x00ffffff,		/* src_mask */
82	 0x00ffffff,		/* dst_mask */
83	 false),		/* pcrel_offset */
84
85  /* A relative 22 bit branch; bits 21-2 are stored in bits 26-7.  */
86  HOWTO (R_ARC_B22_PCREL,	/* type */
87	 2,			/* rightshift */
88	 2,			/* size (0 = byte, 1 = short, 2 = long) */
89	 22,			/* bitsize */
90	 true,			/* pc_relative */
91	 7,			/* bitpos */
92	 complain_overflow_signed, /* complain_on_overflow */
93	 bfd_elf_generic_reloc,	/* special_function */
94	 "R_ARC_B22_PCREL",	/* name */
95	 false,			/* partial_inplace */
96	 0x07ffff80,		/* src_mask */
97	 0x07ffff80,		/* dst_mask */
98	 true),			/* pcrel_offset */
99
100};
101
102/* Map BFD reloc types to ARC ELF reloc types.  */
103
104struct arc_reloc_map
105{
106  bfd_reloc_code_real_type bfd_reloc_val;
107  unsigned char elf_reloc_val;
108};
109
110static const struct arc_reloc_map arc_reloc_map[] =
111{
112  { BFD_RELOC_NONE, R_ARC_NONE, },
113  { BFD_RELOC_32, R_ARC_32 },
114  { BFD_RELOC_CTOR, R_ARC_32 },
115  { BFD_RELOC_ARC_B26, R_ARC_B26 },
116  { BFD_RELOC_ARC_B22_PCREL, R_ARC_B22_PCREL },
117};
118
119static reloc_howto_type *
120bfd_elf32_bfd_reloc_type_lookup (abfd, code)
121     bfd *abfd ATTRIBUTE_UNUSED;
122     bfd_reloc_code_real_type code;
123{
124  unsigned int i;
125
126  for (i = 0;
127       i < sizeof (arc_reloc_map) / sizeof (struct arc_reloc_map);
128       i++)
129    {
130      if (arc_reloc_map[i].bfd_reloc_val == code)
131	return &elf_arc_howto_table[arc_reloc_map[i].elf_reloc_val];
132    }
133
134  return NULL;
135}
136
137/* Set the howto pointer for an ARC ELF reloc.  */
138
139static void
140arc_info_to_howto_rel (abfd, cache_ptr, dst)
141     bfd *abfd ATTRIBUTE_UNUSED;
142     arelent *cache_ptr;
143     Elf32_Internal_Rel *dst;
144{
145  unsigned int r_type;
146
147  r_type = ELF32_R_TYPE (dst->r_info);
148  BFD_ASSERT (r_type < (unsigned int) R_ARC_max);
149  cache_ptr->howto = &elf_arc_howto_table[r_type];
150}
151
152/* Set the right machine number for an ARC ELF file.  */
153
154static boolean
155arc_elf_object_p (abfd)
156     bfd *abfd;
157{
158  int mach;
159  unsigned long arch = elf_elfheader (abfd)->e_flags & EF_ARC_MACH;
160
161  switch (arch)
162    {
163    case E_ARC_MACH_BASE:
164      mach = bfd_mach_arc_base;
165      break;
166    default:
167      /* Unknown cpu type.  ??? What to do?  */
168      return false;
169    }
170
171  (void) bfd_default_set_arch_mach (abfd, bfd_arch_arc, mach);
172  return true;
173}
174
175/* The final processing done just before writing out an ARC ELF object file.
176   This gets the ARC architecture right based on the machine number.  */
177
178static void
179arc_elf_final_write_processing (abfd, linker)
180     bfd *abfd;
181     boolean linker ATTRIBUTE_UNUSED;
182{
183  int mach;
184  unsigned long val;
185
186  switch (mach = bfd_get_mach (abfd))
187    {
188    case bfd_mach_arc_base:
189      val = E_ARC_MACH_BASE;
190      break;
191    default:
192      return;
193    }
194
195  elf_elfheader (abfd)->e_flags &=~ EF_ARC_MACH;
196  elf_elfheader (abfd)->e_flags |= val;
197}
198
199#define TARGET_LITTLE_SYM	bfd_elf32_littlearc_vec
200#define TARGET_LITTLE_NAME	"elf32-littlearc"
201#define TARGET_BIG_SYM		bfd_elf32_bigarc_vec
202#define TARGET_BIG_NAME		"elf32-bigarc"
203#define ELF_ARCH		bfd_arch_arc
204#define ELF_MACHINE_CODE	EM_CYGNUS_ARC
205#define ELF_MAXPAGESIZE		0x1000
206
207#define elf_info_to_howto	0
208#define elf_info_to_howto_rel	arc_info_to_howto_rel
209#define elf_backend_object_p	arc_elf_object_p
210#define elf_backend_final_write_processing \
211				arc_elf_final_write_processing
212
213#include "elf32-target.h"
214