Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 1 | /*****************************************************************************\ |
| 2 | * layout.c |
| 3 | * $Id: layout.c,v 1.2 2006/01/24 00:25:40 dsp_llnl Exp $ |
| 4 | ***************************************************************************** |
| 5 | * Copyright (C) 2002-2005 The Regents of the University of California. |
| 6 | * Produced at the Lawrence Livermore National Laboratory. |
| 7 | * Written by Dave Peterson <dsp@llnl.gov> <dave_peterson@pobox.com>. |
| 8 | * UCRL-CODE-2003-012 |
| 9 | * All rights reserved. |
| 10 | * |
| 11 | * This file is part of lxbios, a utility for reading/writing LinuxBIOS |
| 12 | * parameters and displaying information from the LinuxBIOS table. |
| 13 | * For details, see <http://www.llnl.gov/linux/lxbios/>. |
| 14 | * |
| 15 | * Please also read the file DISCLAIMER which is included in this software |
| 16 | * distribution. |
| 17 | * |
| 18 | * This program is free software; you can redistribute it and/or modify it |
| 19 | * under the terms of the GNU General Public License (as published by the |
| 20 | * Free Software Foundation) version 2, dated June 1991. |
| 21 | * |
| 22 | * This program is distributed in the hope that it will be useful, but |
| 23 | * WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF |
| 24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and |
| 25 | * conditions of the GNU General Public License for more details. |
| 26 | * |
| 27 | * You should have received a copy of the GNU General Public License along |
| 28 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 29 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
| 30 | \*****************************************************************************/ |
| 31 | |
| 32 | #include "common.h" |
| 33 | #include "layout.h" |
| 34 | #include "cmos_lowlevel.h" |
| 35 | |
| 36 | typedef struct cmos_entry_item_t cmos_entry_item_t; |
| 37 | |
| 38 | struct cmos_entry_item_t |
| 39 | { cmos_entry_t item; |
| 40 | cmos_entry_item_t *next; |
| 41 | }; |
| 42 | |
| 43 | typedef struct cmos_enum_item_t cmos_enum_item_t; |
| 44 | |
| 45 | struct cmos_enum_item_t |
| 46 | { cmos_enum_t item; |
| 47 | cmos_enum_item_t *next; |
| 48 | }; |
| 49 | |
| 50 | static void default_cmos_layout_get_fn (void); |
| 51 | static int areas_overlap (unsigned area_0_start, unsigned area_0_length, |
| 52 | unsigned area_1_start, unsigned area_1_length); |
| 53 | static int entries_overlap (const cmos_entry_t *p, const cmos_entry_t *q); |
| 54 | static const cmos_enum_item_t * find_first_cmos_enum_id (unsigned config_id); |
| 55 | |
| 56 | const char checksum_param_name[] = "check_sum"; |
| 57 | |
| 58 | /* Newer versions of LinuxBIOS store the 3 pieces of information below in the |
| 59 | * LinuxBIOS table so we don't have to rely on hardcoded values. |
| 60 | */ |
| 61 | |
| 62 | /* This is the offset from the start of CMOS of the first byte that the |
| 63 | * checksum is calculated over. |
| 64 | */ |
| 65 | #define CMOS_CHECKSUM_START 49 |
| 66 | |
| 67 | /* This is the offset from the start of CMOS of the last byte that the |
| 68 | * checksum is calculated over. |
| 69 | */ |
| 70 | #define CMOS_CHECKSUM_END 125 |
| 71 | |
| 72 | /* This is the offset from the start of CMOS where the LinuxBIOS checksum is |
| 73 | * stored. |
| 74 | */ |
| 75 | #define CMOS_CHECKSUM_INDEX 126 |
| 76 | |
| 77 | /* index of first byte of checksummed area */ |
| 78 | unsigned cmos_checksum_start = CMOS_CHECKSUM_START; |
| 79 | |
| 80 | /* index of last byte of checksummed area */ |
| 81 | unsigned cmos_checksum_end = CMOS_CHECKSUM_END; |
| 82 | |
| 83 | /* index of first byte of CMOS checksum (a big-endian 16-bit value) */ |
| 84 | unsigned cmos_checksum_index = CMOS_CHECKSUM_INDEX; |
| 85 | |
| 86 | /* List is sorted in ascending order according to 'bit' field in |
| 87 | * cmos_entry_t. |
| 88 | */ |
| 89 | static cmos_entry_item_t *cmos_entry_list = NULL; |
| 90 | |
| 91 | /* List is sorted in ascending order: first by 'config_id' and then by |
| 92 | * 'value'. |
| 93 | */ |
| 94 | static cmos_enum_item_t *cmos_enum_list = NULL; |
| 95 | |
| 96 | static cmos_layout_get_fn_t cmos_layout_get_fn = default_cmos_layout_get_fn; |
| 97 | |
| 98 | /**************************************************************************** |
| 99 | * entries_overlap |
| 100 | * |
| 101 | * Return 1 if cmos entries 'p' and 'q' overlap. Else return 0. |
| 102 | ****************************************************************************/ |
| 103 | static inline int entries_overlap (const cmos_entry_t *p, |
| 104 | const cmos_entry_t *q) |
| 105 | { return areas_overlap(p->bit, p->length, q->bit, q->length); } |
| 106 | |
| 107 | /**************************************************************************** |
| 108 | * cmos_entry_to_const_item |
| 109 | * |
| 110 | * Return a pointer to the cmos_entry_item_t that 'p' is embedded within. |
| 111 | ****************************************************************************/ |
| 112 | static inline const cmos_entry_item_t * cmos_entry_to_const_item |
| 113 | (const cmos_entry_t *p) |
| 114 | { static const cmos_entry_t *pos = &((cmos_entry_item_t *) 0)->item; |
| 115 | unsigned long offset, address; |
| 116 | |
| 117 | offset = (unsigned long) pos; |
| 118 | address = ((unsigned long) p) - offset; |
| 119 | return (const cmos_entry_item_t *) address; |
| 120 | } |
| 121 | |
| 122 | /**************************************************************************** |
| 123 | * cmos_enum_to_const_item |
| 124 | * |
| 125 | * Return a pointer to the cmos_enum_item_t that 'p' is embedded within. |
| 126 | ****************************************************************************/ |
| 127 | static inline const cmos_enum_item_t * cmos_enum_to_const_item |
| 128 | (const cmos_enum_t *p) |
| 129 | { static const cmos_enum_t *pos = &((cmos_enum_item_t *) 0)->item; |
| 130 | unsigned long offset, address; |
| 131 | |
| 132 | offset = (unsigned long) pos; |
| 133 | address = ((unsigned long) p) - offset; |
| 134 | return (const cmos_enum_item_t *) address; |
| 135 | } |
| 136 | |
| 137 | /**************************************************************************** |
| 138 | * register_cmos_layout_get_fn |
| 139 | * |
| 140 | * Set 'fn' as the function that will be called to retrieve CMOS layout |
| 141 | * information. |
| 142 | ****************************************************************************/ |
| 143 | void register_cmos_layout_get_fn (cmos_layout_get_fn_t fn) |
| 144 | { cmos_layout_get_fn = fn; } |
| 145 | |
| 146 | /**************************************************************************** |
| 147 | * get_cmos_layout |
| 148 | * |
| 149 | * Retrieve CMOS layout information and store it in our internal repository. |
| 150 | ****************************************************************************/ |
| 151 | void get_cmos_layout (void) |
| 152 | { cmos_layout_get_fn(); } |
| 153 | |
| 154 | /**************************************************************************** |
| 155 | * add_cmos_entry |
| 156 | * |
| 157 | * Attempt to add CMOS entry 'e' to our internal repository of layout |
| 158 | * information. Return OK on success or an error code on failure. If |
| 159 | * operation fails because 'e' overlaps an existing CMOS entry, '*conflict' |
| 160 | * will be set to point to the overlapping entry. |
| 161 | ****************************************************************************/ |
| 162 | int add_cmos_entry (const cmos_entry_t *e, const cmos_entry_t **conflict) |
| 163 | { cmos_entry_item_t *item, *prev, *new_entry; |
| 164 | |
| 165 | *conflict = NULL; |
| 166 | |
| 167 | if (e->length < 1) |
| 168 | return LAYOUT_ENTRY_BAD_LENGTH; |
| 169 | |
| 170 | if ((new_entry = (cmos_entry_item_t *) malloc(sizeof(*new_entry))) == NULL) |
| 171 | out_of_memory(); |
| 172 | |
| 173 | new_entry->item = *e; |
| 174 | |
| 175 | if (cmos_entry_list == NULL) |
| 176 | { new_entry->next = NULL; |
| 177 | cmos_entry_list = new_entry; |
| 178 | return OK; |
| 179 | } |
| 180 | |
| 181 | /* Find place in list to insert new entry. List is sorted in ascending |
| 182 | * order. |
| 183 | */ |
| 184 | for (item = cmos_entry_list, prev = NULL; |
| 185 | (item != NULL) && (item->item.bit < e->bit); |
| 186 | prev = item, item = item->next); |
| 187 | |
| 188 | if (prev == NULL) |
| 189 | { if (entries_overlap(e, &cmos_entry_list->item)) |
| 190 | { *conflict = &cmos_entry_list->item; |
| 191 | goto fail; |
| 192 | } |
| 193 | |
| 194 | new_entry->next = cmos_entry_list; |
| 195 | cmos_entry_list = new_entry; |
| 196 | return OK; |
| 197 | } |
| 198 | |
| 199 | if (entries_overlap(&prev->item, e)) |
| 200 | { *conflict = &prev->item; |
| 201 | goto fail; |
| 202 | } |
| 203 | |
| 204 | if ((item != NULL) && entries_overlap(e, &item->item)) |
| 205 | { *conflict = &item->item; |
| 206 | goto fail; |
| 207 | } |
| 208 | |
| 209 | new_entry->next = item; |
| 210 | prev->next = new_entry; |
| 211 | return OK; |
| 212 | |
| 213 | fail: |
| 214 | free(new_entry); |
| 215 | return LAYOUT_ENTRY_OVERLAP; |
| 216 | } |
| 217 | |
| 218 | /**************************************************************************** |
| 219 | * find_cmos_entry |
| 220 | * |
| 221 | * Search for a CMOS entry whose name is 'name'. Return pointer to matching |
| 222 | * entry or NULL if entry not found. |
| 223 | ****************************************************************************/ |
| 224 | const cmos_entry_t * find_cmos_entry (const char name[]) |
| 225 | { cmos_entry_item_t *item; |
| 226 | |
| 227 | for (item = cmos_entry_list; item != NULL; item = item->next) |
| 228 | { if (!strcmp(item->item.name, name)) |
| 229 | return &item->item; |
| 230 | } |
| 231 | |
| 232 | return NULL; |
| 233 | } |
| 234 | |
| 235 | /**************************************************************************** |
| 236 | * first_cmos_entry |
| 237 | * |
| 238 | * Return a pointer to the first CMOS entry in our list or NULL if list is |
| 239 | * empty. |
| 240 | ****************************************************************************/ |
| 241 | const cmos_entry_t * first_cmos_entry (void) |
| 242 | { return (cmos_entry_list == NULL) ? NULL : &cmos_entry_list->item; } |
| 243 | |
| 244 | /**************************************************************************** |
| 245 | * next_cmos_entry |
| 246 | * |
| 247 | * Return a pointer to next entry in list after 'last' or NULL if no more |
| 248 | * entries. |
| 249 | ****************************************************************************/ |
| 250 | const cmos_entry_t * next_cmos_entry (const cmos_entry_t *last) |
| 251 | { const cmos_entry_item_t *last_item, *next_item; |
| 252 | |
| 253 | last_item = cmos_entry_to_const_item(last); |
| 254 | next_item = last_item->next; |
| 255 | return (next_item == NULL) ? NULL : &next_item->item; |
| 256 | } |
| 257 | |
| 258 | /**************************************************************************** |
| 259 | * add_cmos_enum |
| 260 | * |
| 261 | * Attempt to add CMOS enum 'e' to our internal repository of layout |
| 262 | * information. Return OK on success or an error code on failure. |
| 263 | ****************************************************************************/ |
| 264 | int add_cmos_enum (const cmos_enum_t *e) |
| 265 | { cmos_enum_item_t *item, *prev, *new_enum; |
| 266 | |
| 267 | if ((new_enum = (cmos_enum_item_t *) malloc(sizeof(*new_enum))) == NULL) |
| 268 | out_of_memory(); |
| 269 | |
| 270 | new_enum->item = *e; |
| 271 | |
| 272 | if (cmos_enum_list == NULL) |
| 273 | { new_enum->next = NULL; |
| 274 | cmos_enum_list = new_enum; |
| 275 | return OK; |
| 276 | } |
| 277 | |
| 278 | /* The list of enums is sorted in ascending order, first by 'config_id' and |
| 279 | * then by 'value'. Look for the first enum whose 'config_id' field |
| 280 | * matches 'e'. |
| 281 | */ |
| 282 | for (item = cmos_enum_list, prev = NULL; |
| 283 | (item != NULL) && (item->item.config_id < e->config_id); |
| 284 | prev = item, item = item->next); |
| 285 | |
| 286 | if (item == NULL) |
| 287 | { new_enum->next = NULL; |
| 288 | prev->next = new_enum; |
| 289 | return OK; |
| 290 | } |
| 291 | |
| 292 | if (item->item.config_id > e->config_id) |
| 293 | { new_enum->next = item; |
| 294 | |
| 295 | if (prev == NULL) |
| 296 | cmos_enum_list = new_enum; |
| 297 | else |
| 298 | prev->next = new_enum; |
| 299 | |
| 300 | return OK; |
| 301 | } |
| 302 | |
| 303 | /* List already contains at least one enum whose 'config_id' matches 'e'. |
| 304 | * Now find proper place to insert 'e' based on 'value'. |
| 305 | */ |
| 306 | while (item->item.value < e->value) |
| 307 | { prev = item; |
| 308 | item = item->next; |
| 309 | |
| 310 | if ((item == NULL) || (item->item.config_id != e->config_id)) |
| 311 | { new_enum->next = item; |
| 312 | prev->next = new_enum; |
| 313 | return OK; |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | if (item->item.value == e->value) |
| 318 | { free(new_enum); |
| 319 | return LAYOUT_DUPLICATE_ENUM; |
| 320 | } |
| 321 | |
| 322 | new_enum->next = item; |
| 323 | |
| 324 | if (prev == NULL) |
| 325 | cmos_enum_list = new_enum; |
| 326 | else |
| 327 | prev->next = new_enum; |
| 328 | |
| 329 | return OK; |
| 330 | } |
| 331 | |
| 332 | /**************************************************************************** |
| 333 | * find_cmos_enum |
| 334 | * |
| 335 | * Search for an enum that matches 'config_id' and 'value'. If found, return |
| 336 | * a pointer to the mathcing enum. Else return NULL. |
| 337 | ****************************************************************************/ |
| 338 | const cmos_enum_t * find_cmos_enum (unsigned config_id, |
| 339 | unsigned long long value) |
| 340 | { const cmos_enum_item_t *item; |
| 341 | |
| 342 | if ((item = find_first_cmos_enum_id(config_id)) == NULL) |
| 343 | return NULL; |
| 344 | |
| 345 | while (item->item.value < value) |
| 346 | { item = item->next; |
| 347 | |
| 348 | if ((item == NULL) || (item->item.config_id != config_id)) |
| 349 | return NULL; |
| 350 | } |
| 351 | |
| 352 | return (item->item.value == value) ? &item->item : NULL; |
| 353 | } |
| 354 | |
| 355 | /**************************************************************************** |
| 356 | * first_cmos_enum |
| 357 | * |
| 358 | * Return a pointer to the first CMOS enum in our list or NULL if list is |
| 359 | * empty. |
| 360 | ****************************************************************************/ |
| 361 | const cmos_enum_t * first_cmos_enum (void) |
| 362 | { return (cmos_enum_list == NULL) ? NULL : &cmos_enum_list->item; } |
| 363 | |
| 364 | /**************************************************************************** |
| 365 | * next_cmos_enum |
| 366 | * |
| 367 | * Return a pointer to next enum in list after 'last' or NULL if no more |
| 368 | * enums. |
| 369 | ****************************************************************************/ |
| 370 | const cmos_enum_t * next_cmos_enum (const cmos_enum_t *last) |
| 371 | { const cmos_enum_item_t *last_item, *next_item; |
| 372 | |
| 373 | last_item = cmos_enum_to_const_item(last); |
| 374 | next_item = last_item->next; |
| 375 | return (next_item == NULL) ? NULL : &next_item->item; |
| 376 | } |
| 377 | |
| 378 | /**************************************************************************** |
| 379 | * first_cmos_enum_id |
| 380 | * |
| 381 | * Return a pointer to the first CMOS enum in our list that matches |
| 382 | * 'config_id' or NULL if there are no matching enums. |
| 383 | ****************************************************************************/ |
| 384 | const cmos_enum_t * first_cmos_enum_id (unsigned config_id) |
| 385 | { const cmos_enum_item_t *item; |
| 386 | |
| 387 | item = find_first_cmos_enum_id(config_id); |
| 388 | return (item == NULL) ? NULL : &item->item; |
| 389 | } |
| 390 | |
| 391 | /**************************************************************************** |
| 392 | * next_cmos_enum_id |
| 393 | * |
| 394 | * Return a pointer to next enum in list after 'last' that matches the |
| 395 | * 'config_id' field of 'last' or NULL if there are no more matching enums. |
| 396 | ****************************************************************************/ |
| 397 | const cmos_enum_t * next_cmos_enum_id (const cmos_enum_t *last) |
| 398 | { const cmos_enum_item_t *item; |
| 399 | |
| 400 | item = cmos_enum_to_const_item(last)->next; |
| 401 | return ((item == NULL) || (item->item.config_id != last->config_id)) ? |
| 402 | NULL : &item->item; |
| 403 | } |
| 404 | |
| 405 | /**************************************************************************** |
| 406 | * is_checksum_name |
| 407 | * |
| 408 | * Return 1 if 'name' matches the name of the parameter representing the CMOS |
| 409 | * checksum. Else return 0. |
| 410 | ****************************************************************************/ |
| 411 | int is_checksum_name (const char name[]) |
| 412 | { return !strcmp(name, checksum_param_name); } |
| 413 | |
| 414 | /**************************************************************************** |
| 415 | * checksum_layout_to_bytes |
| 416 | * |
| 417 | * On entry, '*layout' contains checksum-related layout information expressed |
| 418 | * in bits. Perform sanity checking on the information and convert it from |
| 419 | * bit positions to byte positions. Return OK on success or an error code if |
| 420 | * a sanity check fails. |
| 421 | ****************************************************************************/ |
| 422 | int checksum_layout_to_bytes (cmos_checksum_layout_t *layout) |
| 423 | { unsigned start, end, index; |
| 424 | |
| 425 | start = layout->summed_area_start; |
| 426 | end = layout->summed_area_end; |
| 427 | index = layout->checksum_at; |
| 428 | |
| 429 | if (start % 8) |
| 430 | return LAYOUT_SUMMED_AREA_START_NOT_ALIGNED; |
| 431 | |
| 432 | if ((end % 8) != 7) |
| 433 | return LAYOUT_SUMMED_AREA_END_NOT_ALIGNED; |
| 434 | |
| 435 | if (index % 8) |
| 436 | return LAYOUT_CHECKSUM_LOCATION_NOT_ALIGNED; |
| 437 | |
| 438 | if (end <= start) |
| 439 | return LAYOUT_INVALID_SUMMED_AREA; |
| 440 | |
| 441 | /* Convert bit positions to byte positions. */ |
| 442 | start /= 8; |
| 443 | end /= 8; /* equivalent to "end = ((end - 7) / 8)" */ |
| 444 | index /= 8; |
| 445 | |
| 446 | if (verify_cmos_byte_index(start) || verify_cmos_byte_index(end)) |
| 447 | return LAYOUT_SUMMED_AREA_OUT_OF_RANGE; |
| 448 | |
| 449 | if (verify_cmos_byte_index(index)) |
| 450 | return LAYOUT_CHECKSUM_LOCATION_OUT_OF_RANGE; |
| 451 | |
| 452 | /* checksum occupies 16 bits */ |
| 453 | if (areas_overlap(start, end - start + 1, index, index + 1)) |
| 454 | return LAYOUT_CHECKSUM_OVERLAPS_SUMMED_AREA; |
| 455 | |
| 456 | layout->summed_area_start = start; |
| 457 | layout->summed_area_end = end; |
| 458 | layout->checksum_at = index; |
| 459 | return OK; |
| 460 | } |
| 461 | |
| 462 | /**************************************************************************** |
| 463 | * checksum_layout_to_bits |
| 464 | * |
| 465 | * On entry, '*layout' contains checksum-related layout information expressed |
| 466 | * in bytes. Convert this information to bit positions. |
| 467 | ****************************************************************************/ |
| 468 | void checksum_layout_to_bits (cmos_checksum_layout_t *layout) |
| 469 | { layout->summed_area_start *= 8; |
| 470 | layout->summed_area_end = (layout->summed_area_end * 8) + 7; |
| 471 | layout->checksum_at *= 8; |
| 472 | } |
| 473 | |
| 474 | /**************************************************************************** |
| 475 | * default_cmos_layout_get_fn |
| 476 | * |
| 477 | * If this function is ever called, it means that an appropriate callback for |
| 478 | * obtaining CMOS layout information was not set before attempting to |
| 479 | * retrieve layout information. |
| 480 | ****************************************************************************/ |
| 481 | static void default_cmos_layout_get_fn (void) |
| 482 | { BUG(); } |
| 483 | |
| 484 | /**************************************************************************** |
| 485 | * areas_overlap |
| 486 | * |
| 487 | * Return 1 if the two given areas overlap. Else return 0. |
| 488 | ****************************************************************************/ |
| 489 | static int areas_overlap (unsigned area_0_start, unsigned area_0_length, |
| 490 | unsigned area_1_start, unsigned area_1_length) |
| 491 | { unsigned area_0_end, area_1_end; |
| 492 | |
| 493 | area_0_end = area_0_start + area_0_length - 1; |
| 494 | area_1_end = area_1_start + area_1_length - 1; |
| 495 | return ((area_1_start <= area_0_end) && (area_0_start <= area_1_end)); |
| 496 | } |
| 497 | |
| 498 | /**************************************************************************** |
| 499 | * find_first_cmos_enum_id |
| 500 | * |
| 501 | * Return a pointer to the first item in our list of enums that matches |
| 502 | * 'config_id'. Return NULL if there is no matching enum. |
| 503 | ****************************************************************************/ |
| 504 | static const cmos_enum_item_t * find_first_cmos_enum_id (unsigned config_id) |
| 505 | { cmos_enum_item_t *item; |
| 506 | |
| 507 | for (item = cmos_enum_list; |
| 508 | (item != NULL) && (item->item.config_id < config_id); |
| 509 | item = item->next); |
| 510 | |
| 511 | return ((item == NULL) || (item->item.config_id > config_id)) ? |
| 512 | NULL : item; |
| 513 | } |