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annotate lwlink/link.c @ 171:d610b8aef91b
Added LWAR skeleton
| author | lost |
|---|---|
| date | Sun, 01 Mar 2009 19:37:03 +0000 |
| parents | 106c2fe3c9d9 |
| children | 0395e6fd67e9 |
| rev | line source |
|---|---|
| 119 | 1 /* |
| 2 link.c | |
| 3 Copyright © 2009 William Astle | |
| 4 | |
| 5 This file is part of LWLINK. | |
| 6 | |
| 7 LWLINK is free software: you can redistribute it and/or modify it under the | |
| 8 terms of the GNU General Public License as published by the Free Software | |
| 9 Foundation, either version 3 of the License, or (at your option) any later | |
| 10 version. | |
| 11 | |
| 12 This program is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 15 more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License along with | |
| 18 this program. If not, see <http://www.gnu.org/licenses/>. | |
| 19 | |
| 20 | |
| 21 Resolve section and symbol addresses; handle incomplete references | |
| 22 */ | |
| 23 | |
| 24 #ifdef HAVE_CONFIG_H | |
| 25 #include "config.h" | |
| 26 #endif | |
| 27 | |
| 120 | 28 #include <stdio.h> |
| 119 | 29 #include <stdlib.h> |
| 30 | |
| 120 | 31 #include "expr.h" |
| 119 | 32 #include "lwlink.h" |
| 33 #include "util.h" | |
| 34 | |
| 121 | 35 struct section_list *sectlist = NULL; |
| 36 int nsects = 0; | |
| 119 | 37 |
| 171 | 38 void check_section_name(char *name, int *base, fileinfo_t *fn) |
| 39 { | |
| 40 int sn; | |
| 41 for (sn = 0; sn < fn -> nsections; sn++) | |
| 42 { | |
| 43 if (!strcmp(name, fn -> sections[sn].name)) | |
| 44 { | |
| 45 // we have a match | |
| 46 sectlist = lw_realloc(sectlist, sizeof(struct section_list) * (nsects + 1)); | |
| 47 sectlist[nsects].ptr = &(fn -> sections[sn]); | |
| 48 | |
| 49 fn -> sections[sn].processed = 1; | |
| 50 fn -> sections[sn].loadaddress = *base; | |
| 51 *base += fn -> sections[sn].codesize; | |
| 52 nsects++; | |
| 53 } | |
| 54 } | |
| 55 for (sn = 0; sn < fn -> nsubs; fn++) | |
| 56 { | |
| 57 check_section_name(name, base, fn -> subs[sn]); | |
| 58 } | |
| 59 } | |
| 60 | |
| 61 void add_matching_sections(char *name, int yesflags, int noflags, int *base); | |
| 62 void check_section_flags(int yesflags, int noflags, int *base, fileinfo_t *fn) | |
| 63 { | |
| 64 int sn; | |
| 65 for (sn = 0; sn < fn -> nsections; sn++) | |
| 66 { | |
| 67 // ignore if the noflags tell us to | |
| 68 if (noflags && (fn -> sections[sn].flags & noflags)) | |
| 69 continue; | |
| 70 // ignore unless the yesflags tell us not to | |
| 71 if (yesflags && (fn -> sections[sn].flags & yesflags == 0)) | |
| 72 continue; | |
| 73 // ignore it if already processed | |
| 74 if (fn -> sections[sn].processed) | |
| 75 continue; | |
| 76 | |
| 77 // we have a match - now collect *all* sections of the same name! | |
| 78 add_matching_sections(fn -> sections[sn].name, 0, 0, base); | |
| 79 | |
| 80 // and then continue looking for sections | |
| 81 } | |
| 82 for (sn = 0; sn < fn -> nsubs; fn++) | |
| 83 { | |
| 84 check_section_flags(yesflags, noflags, base, fn -> subs[sn]); | |
| 85 } | |
| 86 } | |
| 87 | |
| 88 | |
| 89 | |
| 90 void add_matching_sections(char *name, int yesflags, int noflags, int *base) | |
| 91 { | |
| 92 int fn; | |
| 93 if (name) | |
| 94 { | |
| 95 // named section | |
| 96 // look for all instances of a section by the specified name | |
| 97 // and resolve base addresses and add to the list | |
| 98 for (fn = 0; fn < ninputfiles; fn++) | |
| 99 { | |
| 100 check_section_name(name, base, inputfiles[fn]); | |
| 101 } | |
| 102 } | |
| 103 else | |
| 104 { | |
| 105 // wildcard section | |
| 106 // named section | |
| 107 // look for all instances of a section by the specified name | |
| 108 // and resolve base addresses and add to the list | |
| 109 for (fn = 0; fn < ninputfiles; fn++) | |
| 110 { | |
| 111 check_section_flags(yesflags, noflags, base, inputfiles[fn]); | |
| 112 } | |
| 113 } | |
| 114 } | |
| 115 | |
| 119 | 116 // work out section load order and resolve base addresses for each section |
| 117 // make a list of sections to load in order | |
| 118 void resolve_sections(void) | |
| 119 { | |
| 120 int laddr = 0; | |
| 121 int ln, sn, fn; | |
| 122 | |
| 123 for (ln = 0; ln < linkscript.nlines; ln++) | |
| 124 { | |
| 171 | 125 if (linkscript.lines[ln].loadat >= 0) |
| 126 laddr = linkscript.lines[ln].loadat; | |
| 127 add_matching_sections(linkscript.lines[ln].sectname, linkscript.lines[ln].yesflags, linkscript.lines[ln].noflags, &laddr); | |
| 128 | |
| 119 | 129 if (linkscript.lines[ln].sectname) |
| 130 { | |
| 131 } | |
| 132 else | |
| 133 { | |
| 134 // wildcard section | |
| 135 // look for all sections not yet processed that match flags | |
| 136 | |
| 137 int f = 0; | |
| 138 int fn0, sn0; | |
| 139 char *sname; | |
| 140 | |
| 141 // named section | |
| 142 // look for all instances of a section by the specified name | |
| 143 // and resolve base addresses and add to the list | |
| 144 for (fn0 = 0; fn0 < ninputfiles; fn0++) | |
| 145 { | |
| 146 for (sn0 = 0; sn0 < inputfiles[fn0] -> nsections; sn0++) | |
| 147 { | |
| 148 // ignore if the "no flags" bit says to | |
| 149 if (linkscript.lines[ln].noflags && (inputfiles[fn0] -> sections[sn0].flags & linkscript.lines[ln].noflags)) | |
| 150 continue; | |
| 151 // ignore unless the yes flags tell us not to | |
| 152 if (linkscript.lines[ln].yesflags && (inputfiles[fn0] -> sections[sn0].flags & linkscript.lines[ln].yesflags == 0)) | |
| 153 continue; | |
| 154 if (inputfiles[fn0] -> sections[sn0].processed == 0) | |
| 155 { | |
| 156 sname = inputfiles[fn0] -> sections[sn0].name; | |
| 157 for (fn = 0; fn < ninputfiles; fn++) | |
| 158 { | |
| 159 for (sn = 0; sn < inputfiles[fn] -> nsections; sn++) | |
| 160 { | |
| 161 if (!strcmp(sname, inputfiles[fn] -> sections[sn].name)) | |
| 162 { | |
| 163 // we have a match | |
| 164 sectlist = lw_realloc(sectlist, sizeof(struct section_list) * (nsects + 1)); | |
| 165 sectlist[nsects].ptr = &(inputfiles[fn] -> sections[sn]); | |
| 166 | |
| 167 inputfiles[fn] -> sections[sn].processed = 1; | |
| 168 if (!f && linkscript.lines[ln].loadat >= 0) | |
| 169 { | |
| 170 f = 1; | |
| 171 sectlist[nsects].forceaddr = 1; | |
| 172 laddr = linkscript.lines[ln].loadat; | |
| 173 } | |
| 174 else | |
| 175 { | |
| 176 sectlist[nsects].forceaddr = 0; | |
| 177 } | |
| 178 inputfiles[fn] -> sections[sn].loadaddress = laddr; | |
|
131
5276565799bd
Fixed load addresses of chained sections and subsections to actually increment
lost
parents:
130
diff
changeset
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179 laddr += inputfiles[fn] -> sections[sn].codesize; |
| 119 | 180 nsects++; |
| 181 } | |
| 182 } | |
| 183 } | |
| 184 } | |
| 185 } | |
| 186 } | |
| 187 } | |
| 188 } | |
| 189 | |
| 190 // theoretically, all the base addresses are set now | |
| 191 } | |
| 120 | 192 |
| 171 | 193 lw_expr_stack_t *find_external_sym_recurse(char *sym, fileinfo_t *fn) |
| 194 { | |
| 195 int sn; | |
| 196 lw_expr_stack_t *r; | |
| 197 lw_expr_term_t *term; | |
| 198 symtab_t *se; | |
| 199 int val; | |
| 200 | |
| 201 for (sn = 0; sn < fn -> nsections; sn++) | |
| 202 { | |
| 203 for (se = fn -> sections[sn].exportedsyms; se; se = se -> next) | |
| 204 { | |
| 205 if (!strcmp(sym, se -> sym)) | |
| 206 { | |
| 207 val = se -> offset + fn -> sections[sn].loadaddress; | |
| 208 r = lw_expr_stack_create(); | |
| 209 term = lw_expr_term_create_int(val & 0xffff); | |
| 210 lw_expr_stack_push(r, term); | |
| 211 lw_expr_term_free(term); | |
| 212 return r; | |
| 213 } | |
| 214 } | |
| 215 } | |
| 216 | |
| 217 for (sn = 0; sn < fn -> nsubs; sn++) | |
| 218 { | |
| 219 r = find_external_sym_recurse(sym, fn -> subs[sn]); | |
| 220 if (r) | |
| 221 return r; | |
| 222 } | |
| 223 return NULL; | |
| 224 } | |
| 225 | |
| 120 | 226 // resolve all incomplete references now |
| 227 // anything that is unresolvable at this stage will throw an error | |
| 228 // because we know the load address of every section now | |
| 229 lw_expr_stack_t *resolve_sym(char *sym, int symtype, void *state) | |
| 230 { | |
| 231 section_t *sect = state; | |
| 232 lw_expr_term_t *term; | |
| 233 int val = 0, i, fn; | |
| 234 lw_expr_stack_t *s; | |
| 235 symtab_t *se; | |
| 171 | 236 fileinfo_t *fp; |
| 237 | |
| 120 | 238 if (symtype == 1) |
| 239 { | |
| 240 // local symbol | |
| 241 if (!sym) | |
| 242 { | |
| 243 val = sect -> loadaddress; | |
| 244 goto out; | |
| 245 } | |
| 246 | |
| 247 // start with this section | |
| 248 for (se = sect -> localsyms; se; se = se -> next) | |
| 249 { | |
| 250 if (!strcmp(se -> sym, sym)) | |
| 251 { | |
| 252 val = se -> offset + sect -> loadaddress; | |
| 253 goto out; | |
| 254 } | |
| 255 } | |
| 256 // not in this section - check all sections in this file | |
| 257 for (i = 0; i < sect -> file -> nsections; i++) | |
| 258 { | |
| 259 for (se = sect -> file -> sections[i].localsyms; se; se = se -> next) | |
| 260 { | |
| 261 if (!strcmp(se -> sym, sym)) | |
| 262 { | |
| 263 val = se -> offset + sect -> file -> sections[i].loadaddress; | |
| 264 goto out; | |
| 265 } | |
| 266 } | |
| 267 } | |
| 268 // not found | |
| 269 fprintf(stderr, "Local symbol %s not found in %s:%s\n", sym, sect -> file -> filename, sect -> name); | |
| 270 exit(1); | |
| 271 } | |
| 272 else | |
| 273 { | |
| 274 // external symbol | |
| 275 // read all files in order until found (or not found) | |
| 171 | 276 for (fp = sect -> file; fp; fp = fp -> parent) |
| 277 { | |
| 278 s = find_external_sym_recurse(sym, fp); | |
| 279 if (s) | |
| 280 return s; | |
| 281 } | |
| 282 | |
| 120 | 283 for (fn = 0; fn < ninputfiles; fn++) |
| 284 { | |
| 171 | 285 s = find_external_sym_recurse(sym, inputfiles[fn]); |
| 286 if (s) | |
| 287 return s; | |
| 120 | 288 } |
| 130 | 289 if (sect) |
| 290 { | |
| 291 fprintf(stderr, "External symbol %s not found in %s:%s\n", sym, sect -> file -> filename, sect -> name); | |
| 292 } | |
| 293 else | |
| 294 { | |
| 295 fprintf(stderr, "External symbol %s not found\n", sym); | |
| 296 } | |
| 120 | 297 exit(1); |
| 298 } | |
| 299 fprintf(stderr, "Shouldn't ever get here!!!\n"); | |
| 300 exit(88); | |
| 301 out: | |
| 302 s = lw_expr_stack_create(); | |
| 303 term = lw_expr_term_create_int(val & 0xffff); | |
| 304 lw_expr_stack_push(s, term); | |
| 305 lw_expr_term_free(term); | |
| 306 return s; | |
| 307 } | |
| 308 | |
| 309 void resolve_references(void) | |
| 310 { | |
| 311 int sn; | |
| 312 reloc_t *rl; | |
| 313 int rval; | |
| 121 | 314 |
| 315 // resolve entry point if required | |
| 316 // this must resolve to an *exported* symbol and will resolve to the | |
| 317 // first instance of that symbol | |
| 318 if (linkscript.execsym) | |
| 319 { | |
| 320 lw_expr_stack_t *s; | |
| 321 | |
| 322 s = resolve_sym(linkscript.execsym, 0, NULL); | |
| 323 linkscript.execaddr = lw_expr_get_value(s); | |
| 324 lw_expr_stack_free(s); | |
| 325 } | |
| 120 | 326 |
| 124 | 327 for (sn = 0; sn < nsects; sn++) |
| 120 | 328 { |
| 329 for (rl = sectlist[sn].ptr -> incompletes; rl; rl = rl -> next) | |
| 330 { | |
| 331 // do a "simplify" on the expression | |
| 332 rval = lw_expr_reval(rl -> expr, resolve_sym, sectlist[sn].ptr); | |
| 333 | |
| 334 // is it constant? error out if not | |
| 335 if (rval != 0 || !lw_expr_is_constant(rl -> expr)) | |
| 336 { | |
| 337 fprintf(stderr, "Incomplete reference at %s:%s:%02X\n", sectlist[sn].ptr -> file -> filename, sectlist[sn].ptr -> name, rl -> offset); | |
| 338 exit(1); | |
| 339 } | |
| 340 | |
| 341 // put the value into the relocation address | |
| 342 rval = lw_expr_get_value(rl -> expr); | |
| 343 sectlist[sn].ptr -> code[rl -> offset] = (rval >> 8) & 0xff; | |
| 344 sectlist[sn].ptr -> code[rl -> offset + 1] = rval & 0xff; | |
| 345 } | |
| 346 } | |
| 347 } |