1 /* BFD backend for CRIS a.out binaries. 2 Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2007 3 Free Software Foundation, Inc. 4 Contributed by Axis Communications AB. 5 Written by Hans-Peter Nilsson. 6 7 This file is part of BFD, the Binary File Descriptor library. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 22 MA 02110-1301, USA. */ 23 24 /* See info in the file PORTING for documentation of these macros and 25 functions. Beware; some of the information there is outdated. */ 26 27 #define N_HEADER_IN_TEXT(x) 0 28 #define N_TXTOFF(x) 32 29 #define ENTRY_CAN_BE_ZERO 30 #define TEXT_START_ADDR 0 31 32 /* Without reading symbols to get the text start symbol, there is no way 33 to know where the text segment starts in an a.out file. Defaulting to 34 anything as constant as TEXT_START_ADDR is bad. But we can guess from 35 the entry point, which is usually within the first 64k of the text 36 segment. We also assume here that the text segment is 64k-aligned. 37 FIXME: It is also wrong to assume that data and bss follow immediately 38 after text, but with those, we don't have any choice besides reading 39 symbol info, and luckily there's no pressing need for correctness for 40 those vma:s at this time. */ 41 #define N_TXTADDR(x) ((x).a_entry & ~(bfd_vma) 0xffff) 42 43 /* If you change this to 4, you can not link to an address N*4+2. */ 44 #define SEGMENT_SIZE 2 45 46 /* For some reason, if the a.out file has Z_MAGIC, then 47 adata(abfd).exec_bytes_size is not used, but rather 48 adata(abfd).zmagic_disk_block_size, even though the exec_header is 49 *not* included in the text segment. A simple workaround is to 50 #define ZMAGIC_DISK_BLOCK_SIZE, which is used if defined; otherwise 51 TARGET_PAGE_SIZE is used. */ 52 #define ZMAGIC_DISK_BLOCK_SIZE N_TXTOFF (0) 53 54 /* It seems odd at first to set a page-size this low, but gives greater 55 freedom in where things can be linked. The drawback is that you have 56 to set alignment and padding in linker scripts. */ 57 #define TARGET_PAGE_SIZE SEGMENT_SIZE 58 #define TARGETNAME "a.out-cris" 59 60 /* N_SHARED_LIB gets this reasonable default as of 1999-07-12, but we 61 have to work with 2.9.1. Note that N_SHARED_LIB is used in a 62 SUN-specific context, not applicable to CRIS. */ 63 #define N_SHARED_LIB(x) 0 64 65 /* The definition here seems not used; just provided as a convention. */ 66 #define DEFAULT_ARCH bfd_arch_cris 67 68 /* Do not "beautify" the CONCAT* macro args. Traditional C will not 69 remove whitespace added here, and thus will fail to concatenate 70 the tokens. */ 71 #define MY(OP) CONCAT2 (cris_aout_,OP) 72 #define NAME(x, y) CONCAT3 (cris_aout,_32_,y) 73 74 #include "bfd.h" 75 76 /* Version 1 of the header. */ 77 #define MY_exec_hdr_flags 1 78 79 #define MY_write_object_contents MY (write_object_contents) 80 static bfd_boolean MY (write_object_contents) (bfd *); 81 82 /* Forward this, so we can use a pointer to it in PARAMS. */ 83 struct reloc_ext_external; 84 85 #define MY_swap_ext_reloc_out MY (swap_ext_reloc_out) 86 static void MY (swap_ext_reloc_out) (bfd *, arelent *, struct reloc_ext_external *); 87 88 #define MY_swap_ext_reloc_in MY (swap_ext_reloc_in) 89 static void MY (swap_ext_reloc_in) (bfd *, struct reloc_ext_external *, 90 arelent *, asymbol **, bfd_size_type); 91 92 #define MY_set_sizes MY (set_sizes) 93 static bfd_boolean MY (set_sizes) (bfd *); 94 95 /* To set back reloc_size to ext, we make MY (set_sizes) be called 96 through this construct. Note that MY_set_arch_mach is only called 97 through SET_ARCH_MACH. The default bfd_default_set_arch_mach will 98 not call set_sizes. */ 99 100 #define MY_set_arch_mach NAME (aout, set_arch_mach) 101 #define SET_ARCH_MACH(BFD, EXEC) \ 102 MY_set_arch_mach (BFD, DEFAULT_ARCH, N_MACHTYPE (EXEC)) 103 104 /* These macros describe the binary layout of the reloc information we 105 use in a file. */ 106 #define RELOC_EXT_BITS_EXTERN_LITTLE 0x80 107 #define RELOC_EXT_BITS_TYPE_LITTLE 3 108 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 0 109 110 #ifndef MY_get_section_contents 111 #define MY_get_section_contents aout_32_get_section_contents 112 #endif 113 114 #define MACHTYPE_OK(mtype) ((mtype) == M_CRIS) 115 116 /* Include generic functions (some are overridden above). */ 117 #include "aout32.c" 118 #include "aout-target.h" 119 120 /* We need our own version to set header flags. */ 121 122 static bfd_boolean 123 MY (write_object_contents) (bfd *abfd) 124 { 125 struct external_exec exec_bytes; 126 struct internal_exec *execp = exec_hdr (abfd); 127 128 /* We set the reloc type to RELOC_EXT_SIZE, although setting it at all 129 seems unnecessary when inspecting as and ld behavior (not an 130 exhaustive inspection). The default write_object_contents 131 definition sets RELOC_EXT_SIZE, so we follow suite and set it too. */ 132 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE; 133 134 /* Setting N_SET_MACHTYPE and using N_SET_FLAGS is not performed by 135 the default definition. */ 136 if (bfd_get_arch (abfd) == bfd_arch_cris) 137 N_SET_MACHTYPE (*execp, M_CRIS); 138 139 N_SET_FLAGS (*execp, aout_backend_info (abfd)->exec_hdr_flags); 140 141 WRITE_HEADERS (abfd, execp); 142 143 return TRUE; 144 } 145 146 /* We need our own for these reasons: 147 - Assert that a normal 8, 16 or 32 reloc is output. 148 - Fix what seems to be a weak-bug (perhaps there for valid reasons). */ 149 150 static void 151 MY (swap_ext_reloc_out) (bfd *abfd, 152 arelent *g, 153 struct reloc_ext_external *natptr) 154 { 155 int r_index; 156 int r_extern; 157 unsigned int r_type; 158 bfd_vma r_addend; 159 asymbol *sym = *(g->sym_ptr_ptr); 160 asection *output_section = sym->section->output_section; 161 162 PUT_WORD (abfd, g->address, natptr->r_address); 163 164 r_type = (unsigned int) g->howto->type; 165 166 r_addend = g->addend; 167 if ((sym->flags & BSF_SECTION_SYM) != 0) 168 r_addend += (*(g->sym_ptr_ptr))->section->output_section->vma; 169 170 /* If this relocation is relative to a symbol then set the 171 r_index to the symbols index, and the r_extern bit. 172 173 Absolute symbols can come in in two ways, either as an offset 174 from the abs section, or as a symbol which has an abs value. 175 check for that here. */ 176 177 if (bfd_is_abs_section (bfd_get_section (sym))) 178 { 179 r_extern = 0; 180 r_index = N_ABS; 181 } 182 else if ((sym->flags & BSF_SECTION_SYM) == 0) 183 { 184 if (bfd_is_und_section (bfd_get_section (sym)) 185 /* Remember to check for weak symbols; they count as global. */ 186 || (sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 187 r_extern = 1; 188 else 189 r_extern = 0; 190 r_index = (*(g->sym_ptr_ptr))->KEEPIT; 191 } 192 else 193 { 194 /* Just an ordinary section. */ 195 r_extern = 0; 196 r_index = output_section->target_index; 197 } 198 199 /* The relocation type is the same as the canonical ones, but only 200 the first 3 are used: RELOC_8, RELOC_16, RELOC_32. 201 We may change this later, but assert this for the moment. */ 202 if (r_type > 2) 203 { 204 (*_bfd_error_handler) (_("%s: Invalid relocation type exported: %d"), 205 bfd_get_filename (abfd), r_type); 206 207 bfd_set_error (bfd_error_wrong_format); 208 } 209 210 /* Now the fun stuff. */ 211 natptr->r_index[2] = r_index >> 16; 212 natptr->r_index[1] = r_index >> 8; 213 natptr->r_index[0] = r_index; 214 natptr->r_type[0] = 215 (r_extern ? RELOC_EXT_BITS_EXTERN_LITTLE : 0) 216 | (r_type << RELOC_EXT_BITS_TYPE_SH_LITTLE); 217 218 PUT_WORD (abfd, r_addend, natptr->r_addend); 219 } 220 221 /* We need our own to assert that a normal 8, 16 or 32 reloc is input. */ 222 223 static void 224 MY (swap_ext_reloc_in) (bfd *abfd, 225 struct reloc_ext_external *bytes, 226 arelent *cache_ptr, 227 asymbol **symbols, 228 bfd_size_type symcount) 229 { 230 unsigned int r_index; 231 int r_extern; 232 unsigned int r_type; 233 struct aoutdata *su = &(abfd->tdata.aout_data->a); 234 235 cache_ptr->address = (GET_SWORD (abfd, bytes->r_address)); 236 237 /* Now the fun stuff. */ 238 r_index = (bytes->r_index[2] << 16) 239 | (bytes->r_index[1] << 8) 240 | bytes->r_index[0]; 241 r_extern = (0 != (bytes->r_type[0] & RELOC_EXT_BITS_EXTERN_LITTLE)); 242 r_type = ((bytes->r_type[0]) >> RELOC_EXT_BITS_TYPE_SH_LITTLE) 243 & RELOC_EXT_BITS_TYPE_LITTLE; 244 245 if (r_type > 2) 246 { 247 (*_bfd_error_handler) (_("%B: Invalid relocation type imported: %d"), 248 abfd, r_type); 249 250 bfd_set_error (bfd_error_wrong_format); 251 } 252 253 cache_ptr->howto = howto_table_ext + r_type; 254 255 if (r_extern && r_index > symcount) 256 { 257 (*_bfd_error_handler) 258 (_("%B: Bad relocation record imported: %d"), abfd, r_index); 259 260 bfd_set_error (bfd_error_wrong_format); 261 262 /* We continue, so we can catch further errors. */ 263 r_extern = 0; 264 r_index = N_ABS; 265 } 266 267 /* Magically uses r_extern, symbols etc. Ugly, but it's what's in the 268 default. */ 269 MOVE_ADDRESS (GET_SWORD (abfd, bytes->r_addend)); 270 } 271 272 /* We use the same as the default, except that we also set 273 "obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;", to avoid changing 274 NAME (aout, set_arch_mach) in aoutx. */ 275 276 static bfd_boolean 277 MY (set_sizes) (bfd *abfd) 278 { 279 /* Just as the default in aout-target.h (with some #ifdefs folded)... */ 280 281 adata (abfd).page_size = TARGET_PAGE_SIZE; 282 adata (abfd).segment_size = SEGMENT_SIZE; 283 adata (abfd).zmagic_disk_block_size = ZMAGIC_DISK_BLOCK_SIZE; 284 adata (abfd).exec_bytes_size = EXEC_BYTES_SIZE; 285 286 /* ... except for that we have the extended reloc. The alternative 287 would be to add a check on bfd_arch_cris in NAME (aout, 288 set_arch_mach) in aoutx.h, but I don't want to do that since 289 target-specific things should not be added there. */ 290 291 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE; 292 293 return TRUE; 294 } 295