1 /* 2 * libfdt - Flat Device Tree manipulation 3 * Copyright (C) 2006 David Gibson, IBM Corporation. 4 * 5 * libfdt is dual licensed: you can use it either under the terms of 6 * the GPL, or the BSD license, at your option. 7 * 8 * a) This library is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of the 11 * License, or (at your option) any later version. 12 * 13 * This library 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 19 * License along with this library; if not, write to the Free 20 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, 21 * MA 02110-1301 USA 22 * 23 * Alternatively, 24 * 25 * b) Redistribution and use in source and binary forms, with or 26 * without modification, are permitted provided that the following 27 * conditions are met: 28 * 29 * 1. Redistributions of source code must retain the above 30 * copyright notice, this list of conditions and the following 31 * disclaimer. 32 * 2. Redistributions in binary form must reproduce the above 33 * copyright notice, this list of conditions and the following 34 * disclaimer in the documentation and/or other materials 35 * provided with the distribution. 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 38 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 39 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 40 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 41 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 42 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 47 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 48 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 49 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 50 */ 51 #include "libfdt_env.h" 52 53 #include <fdt.h> 54 #include <libfdt.h> 55 56 #include "libfdt_internal.h" 57 58 static int fdt_sw_probe_(void *fdt) 59 { 60 if (fdt_magic(fdt) == FDT_MAGIC) 61 return -FDT_ERR_BADSTATE; 62 else if (fdt_magic(fdt) != FDT_SW_MAGIC) 63 return -FDT_ERR_BADMAGIC; 64 return 0; 65 } 66 67 #define FDT_SW_PROBE(fdt) \ 68 { \ 69 int err; \ 70 if ((err = fdt_sw_probe_(fdt)) != 0) \ 71 return err; \ 72 } 73 74 /* 'memrsv' state: Initial state after fdt_create() 75 * 76 * Allowed functions: 77 * fdt_add_reservmap_entry() 78 * fdt_finish_reservemap() [moves to 'struct' state] 79 */ 80 static int fdt_sw_probe_memrsv_(void *fdt) 81 { 82 int err = fdt_sw_probe_(fdt); 83 if (err) 84 return err; 85 86 if (fdt_off_dt_strings(fdt) != 0) 87 return -FDT_ERR_BADSTATE; 88 return 0; 89 } 90 91 #define FDT_SW_PROBE_MEMRSV(fdt) \ 92 { \ 93 int err; \ 94 if ((err = fdt_sw_probe_memrsv_(fdt)) != 0) \ 95 return err; \ 96 } 97 98 /* 'struct' state: Enter this state after fdt_finish_reservemap() 99 * 100 * Allowed functions: 101 * fdt_begin_node() 102 * fdt_end_node() 103 * fdt_property*() 104 * fdt_finish() [moves to 'complete' state] 105 */ 106 static int fdt_sw_probe_struct_(void *fdt) 107 { 108 int err = fdt_sw_probe_(fdt); 109 if (err) 110 return err; 111 112 if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) 113 return -FDT_ERR_BADSTATE; 114 return 0; 115 } 116 117 #define FDT_SW_PROBE_STRUCT(fdt) \ 118 { \ 119 int err; \ 120 if ((err = fdt_sw_probe_struct_(fdt)) != 0) \ 121 return err; \ 122 } 123 124 static inline uint32_t sw_flags(void *fdt) 125 { 126 /* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */ 127 return fdt_last_comp_version(fdt); 128 } 129 130 /* 'complete' state: Enter this state after fdt_finish() 131 * 132 * Allowed functions: none 133 */ 134 135 static void *fdt_grab_space_(void *fdt, size_t len) 136 { 137 int offset = fdt_size_dt_struct(fdt); 138 int spaceleft; 139 140 spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt) 141 - fdt_size_dt_strings(fdt); 142 143 if ((offset + len < offset) || (offset + len > spaceleft)) 144 return NULL; 145 146 fdt_set_size_dt_struct(fdt, offset + len); 147 return fdt_offset_ptr_w_(fdt, offset); 148 } 149 150 int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags) 151 { 152 const size_t hdrsize = FDT_ALIGN(sizeof(struct fdt_header), 153 sizeof(struct fdt_reserve_entry)); 154 void *fdt = buf; 155 156 if (bufsize < hdrsize) 157 return -FDT_ERR_NOSPACE; 158 159 if (flags & ~FDT_CREATE_FLAGS_ALL) 160 return -FDT_ERR_BADFLAGS; 161 162 memset(buf, 0, bufsize); 163 164 /* 165 * magic and last_comp_version keep intermediate state during the fdt 166 * creation process, which is replaced with the proper FDT format by 167 * fdt_finish(). 168 * 169 * flags should be accessed with sw_flags(). 170 */ 171 fdt_set_magic(fdt, FDT_SW_MAGIC); 172 fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION); 173 fdt_set_last_comp_version(fdt, flags); 174 175 fdt_set_totalsize(fdt, bufsize); 176 177 fdt_set_off_mem_rsvmap(fdt, hdrsize); 178 fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt)); 179 fdt_set_off_dt_strings(fdt, 0); 180 181 return 0; 182 } 183 184 int fdt_create(void *buf, int bufsize) 185 { 186 return fdt_create_with_flags(buf, bufsize, 0); 187 } 188 189 int fdt_resize(void *fdt, void *buf, int bufsize) 190 { 191 size_t headsize, tailsize; 192 char *oldtail, *newtail; 193 194 FDT_SW_PROBE(fdt); 195 196 headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 197 tailsize = fdt_size_dt_strings(fdt); 198 199 if ((headsize + tailsize) > fdt_totalsize(fdt)) 200 return -FDT_ERR_INTERNAL; 201 202 if ((headsize + tailsize) > bufsize) 203 return -FDT_ERR_NOSPACE; 204 205 oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize; 206 newtail = (char *)buf + bufsize - tailsize; 207 208 /* Two cases to avoid clobbering data if the old and new 209 * buffers partially overlap */ 210 if (buf <= fdt) { 211 memmove(buf, fdt, headsize); 212 memmove(newtail, oldtail, tailsize); 213 } else { 214 memmove(newtail, oldtail, tailsize); 215 memmove(buf, fdt, headsize); 216 } 217 218 fdt_set_totalsize(buf, bufsize); 219 if (fdt_off_dt_strings(buf)) 220 fdt_set_off_dt_strings(buf, bufsize); 221 222 return 0; 223 } 224 225 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size) 226 { 227 struct fdt_reserve_entry *re; 228 int offset; 229 230 FDT_SW_PROBE_MEMRSV(fdt); 231 232 offset = fdt_off_dt_struct(fdt); 233 if ((offset + sizeof(*re)) > fdt_totalsize(fdt)) 234 return -FDT_ERR_NOSPACE; 235 236 re = (struct fdt_reserve_entry *)((char *)fdt + offset); 237 re->address = cpu_to_fdt64(addr); 238 re->size = cpu_to_fdt64(size); 239 240 fdt_set_off_dt_struct(fdt, offset + sizeof(*re)); 241 242 return 0; 243 } 244 245 int fdt_finish_reservemap(void *fdt) 246 { 247 int err = fdt_add_reservemap_entry(fdt, 0, 0); 248 249 if (err) 250 return err; 251 252 fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt)); 253 return 0; 254 } 255 256 int fdt_begin_node(void *fdt, const char *name) 257 { 258 struct fdt_node_header *nh; 259 int namelen; 260 261 FDT_SW_PROBE_STRUCT(fdt); 262 263 namelen = strlen(name) + 1; 264 nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen)); 265 if (! nh) 266 return -FDT_ERR_NOSPACE; 267 268 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); 269 memcpy(nh->name, name, namelen); 270 return 0; 271 } 272 273 int fdt_end_node(void *fdt) 274 { 275 fdt32_t *en; 276 277 FDT_SW_PROBE_STRUCT(fdt); 278 279 en = fdt_grab_space_(fdt, FDT_TAGSIZE); 280 if (! en) 281 return -FDT_ERR_NOSPACE; 282 283 *en = cpu_to_fdt32(FDT_END_NODE); 284 return 0; 285 } 286 287 static int fdt_add_string_(void *fdt, const char *s) 288 { 289 char *strtab = (char *)fdt + fdt_totalsize(fdt); 290 int strtabsize = fdt_size_dt_strings(fdt); 291 int len = strlen(s) + 1; 292 int struct_top, offset; 293 294 offset = -strtabsize - len; 295 struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 296 if (fdt_totalsize(fdt) + offset < struct_top) 297 return 0; /* no more room :( */ 298 299 memcpy(strtab + offset, s, len); 300 fdt_set_size_dt_strings(fdt, strtabsize + len); 301 return offset; 302 } 303 304 /* Must only be used to roll back in case of error */ 305 static void fdt_del_last_string_(void *fdt, const char *s) 306 { 307 int strtabsize = fdt_size_dt_strings(fdt); 308 int len = strlen(s) + 1; 309 310 fdt_set_size_dt_strings(fdt, strtabsize - len); 311 } 312 313 static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) 314 { 315 char *strtab = (char *)fdt + fdt_totalsize(fdt); 316 int strtabsize = fdt_size_dt_strings(fdt); 317 const char *p; 318 319 *allocated = 0; 320 321 p = fdt_find_string_(strtab - strtabsize, strtabsize, s); 322 if (p) 323 return p - strtab; 324 325 *allocated = 1; 326 327 return fdt_add_string_(fdt, s); 328 } 329 330 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp) 331 { 332 struct fdt_property *prop; 333 int nameoff; 334 int allocated; 335 336 FDT_SW_PROBE_STRUCT(fdt); 337 338 /* String de-duplication can be slow, _NO_NAME_DEDUP skips it */ 339 if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) { 340 allocated = 1; 341 nameoff = fdt_add_string_(fdt, name); 342 } else { 343 nameoff = fdt_find_add_string_(fdt, name, &allocated); 344 } 345 if (nameoff == 0) 346 return -FDT_ERR_NOSPACE; 347 348 prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len)); 349 if (! prop) { 350 if (allocated) 351 fdt_del_last_string_(fdt, name); 352 return -FDT_ERR_NOSPACE; 353 } 354 355 prop->tag = cpu_to_fdt32(FDT_PROP); 356 prop->nameoff = cpu_to_fdt32(nameoff); 357 prop->len = cpu_to_fdt32(len); 358 *valp = prop->data; 359 return 0; 360 } 361 362 int fdt_property(void *fdt, const char *name, const void *val, int len) 363 { 364 void *ptr; 365 int ret; 366 367 ret = fdt_property_placeholder(fdt, name, len, &ptr); 368 if (ret) 369 return ret; 370 memcpy(ptr, val, len); 371 return 0; 372 } 373 374 int fdt_finish(void *fdt) 375 { 376 char *p = (char *)fdt; 377 fdt32_t *end; 378 int oldstroffset, newstroffset; 379 uint32_t tag; 380 int offset, nextoffset; 381 382 FDT_SW_PROBE_STRUCT(fdt); 383 384 /* Add terminator */ 385 end = fdt_grab_space_(fdt, sizeof(*end)); 386 if (! end) 387 return -FDT_ERR_NOSPACE; 388 *end = cpu_to_fdt32(FDT_END); 389 390 /* Relocate the string table */ 391 oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt); 392 newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 393 memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt)); 394 fdt_set_off_dt_strings(fdt, newstroffset); 395 396 /* Walk the structure, correcting string offsets */ 397 offset = 0; 398 while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) { 399 if (tag == FDT_PROP) { 400 struct fdt_property *prop = 401 fdt_offset_ptr_w_(fdt, offset); 402 int nameoff; 403 404 nameoff = fdt32_to_cpu(prop->nameoff); 405 nameoff += fdt_size_dt_strings(fdt); 406 prop->nameoff = cpu_to_fdt32(nameoff); 407 } 408 offset = nextoffset; 409 } 410 if (nextoffset < 0) 411 return nextoffset; 412 413 /* Finally, adjust the header */ 414 fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt)); 415 416 /* And fix up fields that were keeping intermediate state. */ 417 fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION); 418 fdt_set_magic(fdt, FDT_MAGIC); 419 420 return 0; 421 } 422