1 /* BFD backend for CRIS a.out binaries. 2 Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2009, 2012 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 Beware; some of the information there is outdated.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 /* The definition here seems not used; just provided as a convention. */ 61 #define DEFAULT_ARCH bfd_arch_cris 62 63 /* Do not "beautify" the CONCAT* macro args. Traditional C will not 64 remove whitespace added here, and thus will fail to concatenate 65 the tokens. */ 66 #define MY(OP) CONCAT2 (cris_aout_,OP) 67 #define NAME(x, y) CONCAT3 (cris_aout,_32_,y) 68 69 #include "sysdep.h" 70 #include "bfd.h" 71 72 /* Version 1 of the header. */ 73 #define MY_exec_hdr_flags 1 74 75 #define MY_write_object_contents MY (write_object_contents) 76 static bfd_boolean MY (write_object_contents) (bfd *); 77 78 /* Forward this, so we can use a pointer to it in PARAMS. */ 79 struct reloc_ext_external; 80 81 #define MY_swap_ext_reloc_out MY (swap_ext_reloc_out) 82 static void MY (swap_ext_reloc_out) (bfd *, arelent *, struct reloc_ext_external *); 83 84 #define MY_swap_ext_reloc_in MY (swap_ext_reloc_in) 85 static void MY (swap_ext_reloc_in) (bfd *, struct reloc_ext_external *, 86 arelent *, asymbol **, bfd_size_type); 87 88 #define MY_set_sizes MY (set_sizes) 89 static bfd_boolean MY (set_sizes) (bfd *); 90 91 /* To set back reloc_size to ext, we make MY (set_sizes) be called 92 through this construct. Note that MY_set_arch_mach is only called 93 through SET_ARCH_MACH. The default bfd_default_set_arch_mach will 94 not call set_sizes. */ 95 96 #define MY_set_arch_mach NAME (aout, set_arch_mach) 97 #define SET_ARCH_MACH(BFD, EXEC) \ 98 MY_set_arch_mach (BFD, DEFAULT_ARCH, N_MACHTYPE (EXEC)) 99 100 /* These macros describe the binary layout of the reloc information we 101 use in a file. */ 102 #define RELOC_EXT_BITS_EXTERN_LITTLE 0x80 103 #define RELOC_EXT_BITS_TYPE_LITTLE 3 104 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 0 105 106 #ifndef MY_get_section_contents 107 #define MY_get_section_contents aout_32_get_section_contents 108 #endif 109 110 #define MACHTYPE_OK(mtype) ((mtype) == M_CRIS) 111 112 /* Include generic functions (some are overridden above). */ 113 #include "aout32.c" 114 #include "aout-target.h" 115 116 /* We need our own version to set header flags. */ 117 118 static bfd_boolean 119 MY (write_object_contents) (bfd *abfd) 120 { 121 struct external_exec exec_bytes; 122 struct internal_exec *execp = exec_hdr (abfd); 123 124 /* We set the reloc type to RELOC_EXT_SIZE, although setting it at all 125 seems unnecessary when inspecting as and ld behavior (not an 126 exhaustive inspection). The default write_object_contents 127 definition sets RELOC_EXT_SIZE, so we follow suite and set it too. */ 128 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE; 129 130 /* Setting N_SET_MACHTYPE and using N_SET_FLAGS is not performed by 131 the default definition. */ 132 if (bfd_get_arch (abfd) == bfd_arch_cris) 133 N_SET_MACHTYPE (*execp, M_CRIS); 134 135 N_SET_FLAGS (*execp, aout_backend_info (abfd)->exec_hdr_flags); 136 137 WRITE_HEADERS (abfd, execp); 138 139 return TRUE; 140 } 141 142 /* We need our own for these reasons: 143 - Assert that a normal 8, 16 or 32 reloc is output. 144 - Fix what seems to be a weak-bug (perhaps there for valid reasons). */ 145 146 static void 147 MY (swap_ext_reloc_out) (bfd *abfd, 148 arelent *g, 149 struct reloc_ext_external *natptr) 150 { 151 int r_index; 152 int r_extern; 153 unsigned int r_type; 154 bfd_vma r_addend; 155 asymbol *sym = *(g->sym_ptr_ptr); 156 asection *output_section = sym->section->output_section; 157 158 PUT_WORD (abfd, g->address, natptr->r_address); 159 160 r_type = (unsigned int) g->howto->type; 161 162 r_addend = g->addend; 163 if ((sym->flags & BSF_SECTION_SYM) != 0) 164 r_addend += (*(g->sym_ptr_ptr))->section->output_section->vma; 165 166 /* If this relocation is relative to a symbol then set the 167 r_index to the symbols index, and the r_extern bit. 168 169 Absolute symbols can come in in two ways, either as an offset 170 from the abs section, or as a symbol which has an abs value. 171 check for that here. */ 172 173 if (bfd_is_abs_section (bfd_get_section (sym))) 174 { 175 r_extern = 0; 176 r_index = N_ABS; 177 } 178 else if ((sym->flags & BSF_SECTION_SYM) == 0) 179 { 180 if (bfd_is_und_section (bfd_get_section (sym)) 181 /* Remember to check for weak symbols; they count as global. */ 182 || (sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 183 r_extern = 1; 184 else 185 r_extern = 0; 186 r_index = (*(g->sym_ptr_ptr))->KEEPIT; 187 } 188 else 189 { 190 /* Just an ordinary section. */ 191 r_extern = 0; 192 r_index = output_section->target_index; 193 } 194 195 /* The relocation type is the same as the canonical ones, but only 196 the first 3 are used: RELOC_8, RELOC_16, RELOC_32. 197 We may change this later, but assert this for the moment. */ 198 if (r_type > 2) 199 { 200 (*_bfd_error_handler) (_("%s: Invalid relocation type exported: %d"), 201 bfd_get_filename (abfd), r_type); 202 203 bfd_set_error (bfd_error_wrong_format); 204 } 205 206 /* Now the fun stuff. */ 207 natptr->r_index[2] = r_index >> 16; 208 natptr->r_index[1] = r_index >> 8; 209 natptr->r_index[0] = r_index; 210 natptr->r_type[0] = 211 (r_extern ? RELOC_EXT_BITS_EXTERN_LITTLE : 0) 212 | (r_type << RELOC_EXT_BITS_TYPE_SH_LITTLE); 213 214 PUT_WORD (abfd, r_addend, natptr->r_addend); 215 } 216 217 /* We need our own to assert that a normal 8, 16 or 32 reloc is input. */ 218 219 static void 220 MY (swap_ext_reloc_in) (bfd *abfd, 221 struct reloc_ext_external *bytes, 222 arelent *cache_ptr, 223 asymbol **symbols, 224 bfd_size_type symcount) 225 { 226 unsigned int r_index; 227 int r_extern; 228 unsigned int r_type; 229 struct aoutdata *su = &(abfd->tdata.aout_data->a); 230 231 cache_ptr->address = (GET_SWORD (abfd, bytes->r_address)); 232 233 /* Now the fun stuff. */ 234 r_index = (bytes->r_index[2] << 16) 235 | (bytes->r_index[1] << 8) 236 | bytes->r_index[0]; 237 r_extern = (0 != (bytes->r_type[0] & RELOC_EXT_BITS_EXTERN_LITTLE)); 238 r_type = ((bytes->r_type[0]) >> RELOC_EXT_BITS_TYPE_SH_LITTLE) 239 & RELOC_EXT_BITS_TYPE_LITTLE; 240 241 if (r_type > 2) 242 { 243 (*_bfd_error_handler) (_("%B: Invalid relocation type imported: %d"), 244 abfd, r_type); 245 246 bfd_set_error (bfd_error_wrong_format); 247 } 248 249 cache_ptr->howto = howto_table_ext + r_type; 250 251 if (r_extern && r_index > symcount) 252 { 253 (*_bfd_error_handler) 254 (_("%B: Bad relocation record imported: %d"), abfd, r_index); 255 256 bfd_set_error (bfd_error_wrong_format); 257 258 /* We continue, so we can catch further errors. */ 259 r_extern = 0; 260 r_index = N_ABS; 261 } 262 263 /* Magically uses r_extern, symbols etc. Ugly, but it's what's in the 264 default. */ 265 MOVE_ADDRESS (GET_SWORD (abfd, bytes->r_addend)); 266 } 267 268 /* We use the same as the default, except that we also set 269 "obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE;", to avoid changing 270 NAME (aout, set_arch_mach) in aoutx. */ 271 272 static bfd_boolean 273 MY (set_sizes) (bfd *abfd) 274 { 275 /* Just as the default in aout-target.h (with some #ifdefs folded)... */ 276 277 adata (abfd).page_size = TARGET_PAGE_SIZE; 278 adata (abfd).segment_size = SEGMENT_SIZE; 279 adata (abfd).zmagic_disk_block_size = ZMAGIC_DISK_BLOCK_SIZE; 280 adata (abfd).exec_bytes_size = EXEC_BYTES_SIZE; 281 282 /* ... except for that we have the extended reloc. The alternative 283 would be to add a check on bfd_arch_cris in NAME (aout, 284 set_arch_mach) in aoutx.h, but I don't want to do that since 285 target-specific things should not be added there. */ 286 287 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE; 288 289 return TRUE; 290 } 291