1 /* BFD backend for CRIS a.out binaries. 2 Copyright (C) 2000-2022 Free Software Foundation, Inc. 3 Contributed by Axis Communications AB. 4 Written by Hans-Peter Nilsson. 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 3 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., 51 Franklin Street - Fifth Floor, Boston, 21 MA 02110-1301, USA. */ 22 23 /* See info in the file PORTING for documentation of these macros and 24 functions. Beware; some of the information there is outdated. */ 25 26 #define N_HEADER_IN_TEXT(x) 0 27 #define N_TXTOFF(x) 32 28 #define ENTRY_CAN_BE_ZERO 29 #define TEXT_START_ADDR 0 30 31 /* Without reading symbols to get the text start symbol, there is no way 32 to know where the text segment starts in an a.out file. Defaulting to 33 anything as constant as TEXT_START_ADDR is bad. But we can guess from 34 the entry point, which is usually within the first 64k of the text 35 segment. We also assume here that the text segment is 64k-aligned. 36 FIXME: It is also wrong to assume that data and bss follow immediately 37 after text, but with those, we don't have any choice besides reading 38 symbol info, and luckily there's no pressing need for correctness for 39 those vma:s at this time. */ 40 #define N_TXTADDR(x) ((x)->a_entry & ~(bfd_vma) 0xffff) 41 42 /* If you change this to 4, you can not link to an address N*4+2. */ 43 #define SEGMENT_SIZE 2 44 45 /* For some reason, if the a.out file has Z_MAGIC, then 46 adata(abfd).exec_bytes_size is not used, but rather 47 adata(abfd).zmagic_disk_block_size, even though the exec_header is 48 *not* included in the text segment. A simple workaround is to 49 #define ZMAGIC_DISK_BLOCK_SIZE, which is used if defined; otherwise 50 TARGET_PAGE_SIZE is used. */ 51 #define ZMAGIC_DISK_BLOCK_SIZE N_TXTOFF (0) 52 53 /* It seems odd at first to set a page-size this low, but gives greater 54 freedom in where things can be linked. The drawback is that you have 55 to set alignment and padding in linker scripts. */ 56 #define TARGET_PAGE_SIZE SEGMENT_SIZE 57 #define TARGETNAME "a.out-cris" 58 59 /* Do not "beautify" the CONCAT* macro args. Traditional C will not 60 remove whitespace added here, and thus will fail to concatenate 61 the tokens. */ 62 #define MY(OP) CONCAT2 (cris_aout_,OP) 63 #define NAME(x, y) CONCAT3 (cris_aout,_32_,y) 64 65 #include "sysdep.h" 66 #include "bfd.h" 67 68 /* Version 1 of the header. */ 69 #define MY_exec_hdr_flags 1 70 71 #define MY_write_object_contents MY (write_object_contents) 72 static bool MY (write_object_contents) (bfd *); 73 74 /* Forward this, so we can use a pointer to it in PARAMS. */ 75 struct reloc_ext_external; 76 77 #define MY_swap_ext_reloc_out MY (swap_ext_reloc_out) 78 static void MY (swap_ext_reloc_out) (bfd *, arelent *, struct reloc_ext_external *); 79 80 #define MY_swap_ext_reloc_in MY (swap_ext_reloc_in) 81 static void MY (swap_ext_reloc_in) (bfd *, struct reloc_ext_external *, 82 arelent *, asymbol **, bfd_size_type); 83 84 #define MY_set_sizes MY (set_sizes) 85 static bool MY (set_sizes) (bfd *); 86 87 /* To set back reloc_size to ext, we make MY (set_sizes) be called 88 through this construct. Note that MY_set_arch_mach is only called 89 through SET_ARCH_MACH. The default bfd_default_set_arch_mach will 90 not call set_sizes. */ 91 92 #define SET_ARCH_MACH(BFD, EXECP) \ 93 bfd_set_arch_mach (BFD, bfd_arch_cris, N_MACHTYPE (EXECP)) 94 95 /* These macros describe the binary layout of the reloc information we 96 use in a file. */ 97 #define RELOC_EXT_BITS_EXTERN_LITTLE 0x80 98 #define RELOC_EXT_BITS_TYPE_LITTLE 3 99 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 0 100 101 #ifndef MY_get_section_contents 102 #define MY_get_section_contents aout_32_get_section_contents 103 #endif 104 105 #define MACHTYPE_OK(mtype) ((mtype) == M_CRIS) 106 107 /* Include generic functions (some are overridden above). */ 108 #include "aout32.c" 109 #include "aout-target.h" 110 111 /* We need our own version to set header flags. */ 112 113 static bool 114 MY (write_object_contents) (bfd *abfd) 115 { 116 struct external_exec exec_bytes; 117 struct internal_exec *execp = exec_hdr (abfd); 118 119 /* We set the reloc type to RELOC_EXT_SIZE, although setting it at all 120 seems unnecessary when inspecting as and ld behavior (not an 121 exhaustive inspection). The default write_object_contents 122 definition sets RELOC_EXT_SIZE, so we follow suite and set it too. */ 123 obj_reloc_entry_size (abfd) = RELOC_EXT_SIZE; 124 125 /* Setting N_SET_MACHTYPE and using N_SET_FLAGS is not performed by 126 the default definition. */ 127 if (bfd_get_arch (abfd) == bfd_arch_cris) 128 N_SET_MACHTYPE (execp, M_CRIS); 129 130 N_SET_FLAGS (execp, aout_backend_info (abfd)->exec_hdr_flags); 131 132 WRITE_HEADERS (abfd, execp); 133 134 return true; 135 } 136 137 /* We need our own for these reasons: 138 - Assert that a normal 8, 16 or 32 reloc is output. 139 - Fix what seems to be a weak-bug (perhaps there for valid reasons). */ 140 141 static void 142 MY (swap_ext_reloc_out) (bfd *abfd, 143 arelent *g, 144 struct reloc_ext_external *natptr) 145 { 146 int r_index; 147 int r_extern; 148 unsigned int r_type; 149 bfd_vma r_addend; 150 asymbol *sym = *(g->sym_ptr_ptr); 151 asection *output_section = sym->section->output_section; 152 153 PUT_WORD (abfd, g->address, natptr->r_address); 154 155 r_type = (unsigned int) g->howto->type; 156 157 r_addend = g->addend; 158 if ((sym->flags & BSF_SECTION_SYM) != 0) 159 r_addend += (*(g->sym_ptr_ptr))->section->output_section->vma; 160 161 /* If this relocation is relative to a symbol then set the 162 r_index to the symbols index, and the r_extern bit. 163 164 Absolute symbols can come in in two ways, either as an offset 165 from the abs section, or as a symbol which has an abs value. 166 check for that here. */ 167 168 if (bfd_is_abs_section (bfd_asymbol_section (sym))) 169 { 170 r_extern = 0; 171 r_index = N_ABS; 172 } 173 else if ((sym->flags & BSF_SECTION_SYM) == 0) 174 { 175 if (bfd_is_und_section (bfd_asymbol_section (sym)) 176 /* Remember to check for weak symbols; they count as global. */ 177 || (sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0) 178 r_extern = 1; 179 else 180 r_extern = 0; 181 r_index = (*(g->sym_ptr_ptr))->KEEPIT; 182 } 183 else 184 { 185 /* Just an ordinary section. */ 186 r_extern = 0; 187 r_index = output_section->target_index; 188 } 189 190 /* The relocation type is the same as the canonical ones, but only 191 the first 3 are used: RELOC_8, RELOC_16, RELOC_32. 192 We may change this later, but assert this for the moment. */ 193 if (r_type > 2) 194 { 195 /* xgettext:c-format */ 196 _bfd_error_handler (_("%pB: unsupported relocation type exported: %#x"), 197 abfd, r_type); 198 199 bfd_set_error (bfd_error_wrong_format); 200 } 201 202 /* Now the fun stuff. */ 203 natptr->r_index[2] = r_index >> 16; 204 natptr->r_index[1] = r_index >> 8; 205 natptr->r_index[0] = r_index; 206 natptr->r_type[0] = 207 (r_extern ? RELOC_EXT_BITS_EXTERN_LITTLE : 0) 208 | (r_type << RELOC_EXT_BITS_TYPE_SH_LITTLE); 209 210 PUT_WORD (abfd, r_addend, natptr->r_addend); 211 } 212 213 /* We need our own to assert that a normal 8, 16 or 32 reloc is input. */ 214 215 static void 216 MY (swap_ext_reloc_in) (bfd *abfd, 217 struct reloc_ext_external *bytes, 218 arelent *cache_ptr, 219 asymbol **symbols, 220 bfd_size_type symcount) 221 { 222 unsigned int r_index; 223 int r_extern; 224 unsigned int r_type; 225 struct aoutdata *su = &(abfd->tdata.aout_data->a); 226 227 cache_ptr->address = (GET_SWORD (abfd, bytes->r_address)); 228 229 /* Now the fun stuff. */ 230 r_index = (((unsigned int) bytes->r_index[2] << 16) 231 | ((unsigned int) bytes->r_index[1] << 8) 232 | bytes->r_index[0]); 233 234 r_extern = (0 != (bytes->r_type[0] & RELOC_EXT_BITS_EXTERN_LITTLE)); 235 236 r_type = ((bytes->r_type[0] & RELOC_EXT_BITS_TYPE_LITTLE) 237 >> RELOC_EXT_BITS_TYPE_SH_LITTLE); 238 239 if (r_type > 2) 240 { 241 /* xgettext:c-format */ 242 _bfd_error_handler (_("%pB: unsupported relocation type imported: %#x"), 243 abfd, r_type); 244 245 bfd_set_error (bfd_error_wrong_format); 246 } 247 248 cache_ptr->howto = howto_table_ext + r_type; 249 250 if (r_extern && r_index > symcount) 251 { 252 _bfd_error_handler 253 /* xgettext:c-format */ 254 (_("%pB: 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 bool 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