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annotate src/link.c @ 316:ba58dbe39c67 1.0
Branched for release 1.0
| author | lost |
|---|---|
| date | Tue, 27 Jan 2009 05:51:54 +0000 |
| parents | c275e7e328d4 |
| children |
| rev | line source |
|---|---|
| 301 | 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 | |
| 302 | 28 #include <stdio.h> |
| 301 | 29 #include <stdlib.h> |
| 30 | |
| 302 | 31 #include "expr.h" |
| 301 | 32 #include "lwlink.h" |
| 33 #include "util.h" | |
| 34 | |
| 303 | 35 struct section_list *sectlist = NULL; |
| 36 int nsects = 0; | |
| 301 | 37 |
| 38 // work out section load order and resolve base addresses for each section | |
| 39 // make a list of sections to load in order | |
| 40 void resolve_sections(void) | |
| 41 { | |
| 42 int laddr = 0; | |
| 43 int ln, sn, fn; | |
| 44 | |
| 45 for (ln = 0; ln < linkscript.nlines; ln++) | |
| 46 { | |
| 308 | 47 // printf("Linker script line %d: '%s', %04X, %d, %d\n", ln, linkscript.lines[ln].sectname, linkscript.lines[ln].loadat, linkscript.lines[ln].yesflags, linkscript.lines[ln].noflags); |
| 301 | 48 if (linkscript.lines[ln].sectname) |
| 49 { | |
| 50 int f = 0; | |
| 51 // named section | |
| 52 // look for all instances of a section by the specified name | |
| 53 // and resolve base addresses and add to the list | |
| 54 for (fn = 0; fn < ninputfiles; fn++) | |
| 55 { | |
| 56 for (sn = 0; sn < inputfiles[fn] -> nsections; sn++) | |
| 57 { | |
| 308 | 58 // printf(" Considering %s:%s\n", inputfiles[fn]->filename, inputfiles[fn]->sections[sn].name); |
| 301 | 59 if (!strcmp(linkscript.lines[ln].sectname, inputfiles[fn] -> sections[sn].name)) |
| 60 { | |
| 61 // we have a match | |
| 62 sectlist = lw_realloc(sectlist, sizeof(struct section_list) * (nsects + 1)); | |
| 63 sectlist[nsects].ptr = &(inputfiles[fn] -> sections[sn]); | |
| 64 | |
| 65 inputfiles[fn] -> sections[sn].processed = 1; | |
| 66 if (!f && linkscript.lines[ln].loadat >= 0) | |
| 67 { | |
| 68 f = 1; | |
| 69 sectlist[nsects].forceaddr = 1; | |
| 70 laddr = linkscript.lines[ln].loadat; | |
| 71 } | |
| 72 else | |
| 73 { | |
| 74 sectlist[nsects].forceaddr = 0; | |
| 75 } | |
| 76 inputfiles[fn] -> sections[sn].loadaddress = laddr; | |
|
313
c275e7e328d4
Fixed load addresses of chained sections and subsections to actually increment
lost
parents:
312
diff
changeset
|
77 laddr += inputfiles[fn] -> sections[sn].codesize; |
| 301 | 78 nsects++; |
| 79 } | |
| 80 } | |
| 81 } | |
| 82 } | |
| 83 else | |
| 84 { | |
| 85 // wildcard section | |
| 86 // look for all sections not yet processed that match flags | |
| 87 | |
| 88 int f = 0; | |
| 89 int fn0, sn0; | |
| 90 char *sname; | |
| 91 | |
| 92 // named section | |
| 93 // look for all instances of a section by the specified name | |
| 94 // and resolve base addresses and add to the list | |
| 95 for (fn0 = 0; fn0 < ninputfiles; fn0++) | |
| 96 { | |
| 97 for (sn0 = 0; sn0 < inputfiles[fn0] -> nsections; sn0++) | |
| 98 { | |
| 99 // ignore if the "no flags" bit says to | |
| 100 if (linkscript.lines[ln].noflags && (inputfiles[fn0] -> sections[sn0].flags & linkscript.lines[ln].noflags)) | |
| 101 continue; | |
| 102 // ignore unless the yes flags tell us not to | |
| 103 if (linkscript.lines[ln].yesflags && (inputfiles[fn0] -> sections[sn0].flags & linkscript.lines[ln].yesflags == 0)) | |
| 104 continue; | |
| 105 if (inputfiles[fn0] -> sections[sn0].processed == 0) | |
| 106 { | |
| 107 sname = inputfiles[fn0] -> sections[sn0].name; | |
| 108 for (fn = 0; fn < ninputfiles; fn++) | |
| 109 { | |
| 110 for (sn = 0; sn < inputfiles[fn] -> nsections; sn++) | |
| 111 { | |
| 112 if (!strcmp(sname, inputfiles[fn] -> sections[sn].name)) | |
| 113 { | |
| 114 // we have a match | |
| 115 sectlist = lw_realloc(sectlist, sizeof(struct section_list) * (nsects + 1)); | |
| 116 sectlist[nsects].ptr = &(inputfiles[fn] -> sections[sn]); | |
| 117 | |
| 118 inputfiles[fn] -> sections[sn].processed = 1; | |
| 119 if (!f && linkscript.lines[ln].loadat >= 0) | |
| 120 { | |
| 121 f = 1; | |
| 122 sectlist[nsects].forceaddr = 1; | |
| 123 laddr = linkscript.lines[ln].loadat; | |
| 124 } | |
| 125 else | |
| 126 { | |
| 127 sectlist[nsects].forceaddr = 0; | |
| 128 } | |
| 129 inputfiles[fn] -> sections[sn].loadaddress = laddr; | |
|
313
c275e7e328d4
Fixed load addresses of chained sections and subsections to actually increment
lost
parents:
312
diff
changeset
|
130 laddr += inputfiles[fn] -> sections[sn].codesize; |
| 301 | 131 nsects++; |
| 132 } | |
| 133 } | |
| 134 } | |
| 135 } | |
| 136 } | |
| 137 } | |
| 138 } | |
| 139 } | |
| 140 | |
| 141 // theoretically, all the base addresses are set now | |
| 142 } | |
| 302 | 143 |
| 144 // resolve all incomplete references now | |
| 145 // anything that is unresolvable at this stage will throw an error | |
| 146 // because we know the load address of every section now | |
| 147 lw_expr_stack_t *resolve_sym(char *sym, int symtype, void *state) | |
| 148 { | |
| 149 section_t *sect = state; | |
| 150 lw_expr_term_t *term; | |
| 151 int val = 0, i, fn; | |
| 152 lw_expr_stack_t *s; | |
| 153 symtab_t *se; | |
| 154 | |
| 155 if (symtype == 1) | |
| 156 { | |
| 157 // local symbol | |
| 158 if (!sym) | |
| 159 { | |
| 160 val = sect -> loadaddress; | |
| 161 goto out; | |
| 162 } | |
| 163 | |
| 164 // start with this section | |
| 165 for (se = sect -> localsyms; se; se = se -> next) | |
| 166 { | |
| 167 if (!strcmp(se -> sym, sym)) | |
| 168 { | |
| 169 val = se -> offset + sect -> loadaddress; | |
| 170 goto out; | |
| 171 } | |
| 172 } | |
| 173 // not in this section - check all sections in this file | |
| 174 for (i = 0; i < sect -> file -> nsections; i++) | |
| 175 { | |
| 176 for (se = sect -> file -> sections[i].localsyms; se; se = se -> next) | |
| 177 { | |
| 178 if (!strcmp(se -> sym, sym)) | |
| 179 { | |
| 180 val = se -> offset + sect -> file -> sections[i].loadaddress; | |
| 181 goto out; | |
| 182 } | |
| 183 } | |
| 184 } | |
| 185 // not found | |
| 186 fprintf(stderr, "Local symbol %s not found in %s:%s\n", sym, sect -> file -> filename, sect -> name); | |
| 187 exit(1); | |
| 188 } | |
| 189 else | |
| 190 { | |
| 191 // external symbol | |
| 192 // read all files in order until found (or not found) | |
| 193 for (fn = 0; fn < ninputfiles; fn++) | |
| 194 { | |
| 195 for (i = 0; i < inputfiles[fn] -> nsections; i++) | |
| 196 { | |
| 197 for (se = inputfiles[fn] -> sections[i].exportedsyms; se; se = se -> next) | |
| 198 { | |
| 199 if (!strcmp(sym, se -> sym)) | |
| 200 { | |
| 201 val = se -> offset + inputfiles[fn] -> sections[i].loadaddress; | |
| 202 goto out; | |
| 203 } | |
| 204 } | |
| 205 } | |
| 206 } | |
| 312 | 207 if (sect) |
| 208 { | |
| 209 fprintf(stderr, "External symbol %s not found in %s:%s\n", sym, sect -> file -> filename, sect -> name); | |
| 210 } | |
| 211 else | |
| 212 { | |
| 213 fprintf(stderr, "External symbol %s not found\n", sym); | |
| 214 } | |
| 302 | 215 exit(1); |
| 216 } | |
| 217 fprintf(stderr, "Shouldn't ever get here!!!\n"); | |
| 218 exit(88); | |
| 219 out: | |
| 220 s = lw_expr_stack_create(); | |
| 221 term = lw_expr_term_create_int(val & 0xffff); | |
| 222 lw_expr_stack_push(s, term); | |
| 223 lw_expr_term_free(term); | |
| 224 return s; | |
| 225 } | |
| 226 | |
| 227 void resolve_references(void) | |
| 228 { | |
| 229 int sn; | |
| 230 reloc_t *rl; | |
| 231 int rval; | |
| 303 | 232 |
| 233 // resolve entry point if required | |
| 234 // this must resolve to an *exported* symbol and will resolve to the | |
| 235 // first instance of that symbol | |
| 236 if (linkscript.execsym) | |
| 237 { | |
| 238 lw_expr_stack_t *s; | |
| 239 | |
| 240 s = resolve_sym(linkscript.execsym, 0, NULL); | |
| 241 linkscript.execaddr = lw_expr_get_value(s); | |
| 242 lw_expr_stack_free(s); | |
| 243 } | |
| 302 | 244 |
| 306 | 245 for (sn = 0; sn < nsects; sn++) |
| 302 | 246 { |
| 247 for (rl = sectlist[sn].ptr -> incompletes; rl; rl = rl -> next) | |
| 248 { | |
| 249 // do a "simplify" on the expression | |
| 250 rval = lw_expr_reval(rl -> expr, resolve_sym, sectlist[sn].ptr); | |
| 251 | |
| 252 // is it constant? error out if not | |
| 253 if (rval != 0 || !lw_expr_is_constant(rl -> expr)) | |
| 254 { | |
| 255 fprintf(stderr, "Incomplete reference at %s:%s:%02X\n", sectlist[sn].ptr -> file -> filename, sectlist[sn].ptr -> name, rl -> offset); | |
| 256 exit(1); | |
| 257 } | |
| 258 | |
| 259 // put the value into the relocation address | |
| 260 rval = lw_expr_get_value(rl -> expr); | |
| 261 sectlist[sn].ptr -> code[rl -> offset] = (rval >> 8) & 0xff; | |
| 262 sectlist[sn].ptr -> code[rl -> offset + 1] = rval & 0xff; | |
| 263 } | |
| 264 } | |
| 265 } |