wdenk | 2d1a537 | 2004-02-23 19:30:57 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2002 |
| 3 | * MAZeT GmbH <www.mazet.de> |
| 4 | * Stephan Linz <linz@mazet.de>, <linz@li-pro.net> |
| 5 | * |
| 6 | * The most stuff comes from PPCBoot and Linux. |
| 7 | * |
| 8 | * IMMS gGmbH <www.imms.de> |
| 9 | * Thomas Elste <info@elste.org> |
| 10 | * |
| 11 | * Modifications for ModNET50 Board |
| 12 | * |
| 13 | * See file CREDITS for list of people who contributed to this |
| 14 | * project. |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or |
| 17 | * modify it under the terms of the GNU General Public License as |
| 18 | * published by the Free Software Foundation; either version 2 of |
| 19 | * the License, or (at your option) any later version. |
| 20 | * |
| 21 | * This program is distributed in the hope that it will be useful, |
| 22 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 23 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 24 | * GNU General Public License for more details. |
| 25 | * |
| 26 | * You should have received a copy of the GNU General Public License |
| 27 | * along with this program; if not, write to the Free Software |
| 28 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 29 | * MA 02111-1307 USA |
| 30 | */ |
| 31 | |
| 32 | #include <common.h> |
| 33 | #include <asm/arch/netarm_registers.h> |
| 34 | |
| 35 | #define SCR (*(volatile unsigned int *)(NETARM_GEN_MODULE_BASE + NETARM_GEN_SYSTEM_CONTROL)) |
| 36 | |
| 37 | #define ALIGN_ABORT_OFF SCR = SCR & ~NETARM_GEN_SYS_CFG_ALIGN_ABORT |
| 38 | #define ALIGN_ABORT_ON SCR = SCR | NETARM_GEN_SYS_CFG_ALIGN_ABORT |
| 39 | |
| 40 | #define PROG_ADDR (0x555*2) |
| 41 | #define SETUP_ADDR (0x555*2) |
| 42 | #define ID_ADDR (0x555*2) |
| 43 | #define UNLOCK_ADDR1 (0x555*2) |
| 44 | #define UNLOCK_ADDR2 (0x2AA*2) |
| 45 | |
| 46 | #define UNLOCK_CMD1 (0xAA) |
| 47 | #define UNLOCK_CMD2 (0x55) |
| 48 | #define ERASE_SUSPEND_CMD (0xB0) |
| 49 | #define ERASE_RESUME_CMD (0x30) |
| 50 | #define RESET_CMD (0xF0) |
| 51 | #define ID_CMD (0x90) |
| 52 | #define SECERASE_CMD (0x30) |
| 53 | #define CHIPERASE_CMD (0x10) |
| 54 | #define PROG_CMD (0xa0) |
| 55 | #define SETUP_CMD (0x80) |
| 56 | |
| 57 | #define DQ2 (0x04) |
| 58 | #define DQ3 (DQ2*2) |
| 59 | #define DQ5 (DQ3*4) |
| 60 | #define DQ6 (DQ5*2) |
| 61 | |
| 62 | #define WRITE_UNLOCK(addr) { \ |
| 63 | *(volatile __u16*)(addr + UNLOCK_ADDR1) = (__u16)UNLOCK_CMD1; \ |
| 64 | *(volatile __u16*)(addr + UNLOCK_ADDR2) = (__u16)UNLOCK_CMD2; \ |
| 65 | } |
| 66 | |
| 67 | #define CONFIG_AM29_RESERVED (0) |
| 68 | #define K (1024) |
| 69 | #define MB (4) |
| 70 | |
| 71 | #define CELL_SIZE (64*K) |
| 72 | #define DEVICE_SIZE (MB*K*K) |
| 73 | #define CELLS_PER_DEVICE (DEVICE_SIZE/CELL_SIZE) |
| 74 | #define RESERVED_CELLS (CONFIG_AM29_RESERVED*K)/CELL_SIZE |
| 75 | #define MAX_FLASH_DEVICES (1) |
| 76 | #define AVAIL_SIZE (DEVICE_SIZE*MAX_FLASH_DEVICES - RESERVED_CELLS*CELL_SIZE) |
| 77 | |
| 78 | |
| 79 | flash_info_t flash_info[CFG_MAX_FLASH_BANKS]; |
| 80 | static __u16 toggling_bits; |
| 81 | |
| 82 | |
| 83 | /*----------------------------------------------------------------------- |
| 84 | */ |
| 85 | ulong flash_get_size (ulong baseaddr, flash_info_t * info) |
| 86 | { |
| 87 | short i; |
| 88 | __u16 flashtest; |
| 89 | |
| 90 | /* Write auto select command sequence and test FLASH answer */ |
| 91 | WRITE_UNLOCK (baseaddr); |
| 92 | *(volatile __u16 *) (baseaddr + ID_ADDR) = (__u16) ID_CMD; |
| 93 | flashtest /* manufacturer ID */ = *(volatile __u16 *) (baseaddr); |
| 94 | *(volatile __u16 *) (baseaddr + ID_ADDR) = (__u16) RESET_CMD; |
| 95 | |
| 96 | switch ((__u32) ((flashtest << 16) + flashtest)) { |
| 97 | case AMD_MANUFACT: |
| 98 | info->flash_id = FLASH_MAN_AMD & FLASH_VENDMASK; |
| 99 | break; |
| 100 | case FUJ_MANUFACT: |
| 101 | info->flash_id = FLASH_MAN_FUJ & FLASH_VENDMASK; |
| 102 | break; |
| 103 | default: |
| 104 | info->flash_id = FLASH_UNKNOWN; |
| 105 | info->sector_count = 0; |
| 106 | info->size = 0; |
| 107 | return (0); /* no or unknown flash */ |
| 108 | } |
| 109 | |
| 110 | /* Write auto select command sequence and test FLASH answer */ |
| 111 | WRITE_UNLOCK (baseaddr); |
| 112 | *(volatile __u16 *) (baseaddr + ID_ADDR) = (__u16) ID_CMD; |
| 113 | flashtest /* device ID */ = *(volatile __u16 *) (baseaddr + 2); |
| 114 | *(volatile __u16 *) (baseaddr + ID_ADDR) = (__u16) RESET_CMD; |
| 115 | |
| 116 | /* toggling_bits = (flashtest == TOSHIBA)?(DQ6):(DQ2|DQ6); */ |
| 117 | toggling_bits = (DQ2 | DQ6); |
| 118 | |
| 119 | switch ((__u32) ((flashtest << 16) + flashtest)) { |
| 120 | case AMD_ID_LV160B: |
| 121 | info->flash_id += |
| 122 | (FLASH_AM160LV | FLASH_AM160B) & FLASH_TYPEMASK; |
| 123 | info->sector_count = CFG_MAX_FLASH_SECT; |
| 124 | info->size = CFG_FLASH_SIZE; |
| 125 | /* 1*16K Boot Block |
| 126 | 2*8K Parameter Block |
| 127 | 1*32K Small Main Block */ |
| 128 | info->start[0] = baseaddr; |
| 129 | info->start[1] = baseaddr + 0x4000; |
| 130 | info->start[2] = baseaddr + 0x6000; |
| 131 | info->start[3] = baseaddr + 0x8000; |
| 132 | for (i = 1; i < info->sector_count; i++) |
| 133 | info->start[3 + i] = baseaddr + i * CFG_MAIN_SECT_SIZE; |
| 134 | break; |
| 135 | default: |
| 136 | info->flash_id = FLASH_UNKNOWN; |
| 137 | return (0); /* no or unknown flash */ |
| 138 | } |
| 139 | |
| 140 | for (i = 0; i < info->sector_count; i++) { |
| 141 | /* Write auto select command sequence and test FLASH answer */ |
| 142 | WRITE_UNLOCK (info->start[i]); |
| 143 | *(volatile __u16 *) (info->start[i] + ID_ADDR) = (__u16) ID_CMD; |
| 144 | flashtest /* protected verify */ = *(volatile __u16 *) (info->start[i] + 4); |
| 145 | *(volatile __u16 *) (info->start[i] + ID_ADDR) = (__u16) RESET_CMD; |
| 146 | if (flashtest & 0x0001) { |
| 147 | info->protect[i] = 1; /* D0 = 1 if protected */ |
| 148 | } else { |
| 149 | info->protect[i] = 0; |
| 150 | } |
| 151 | } |
| 152 | return (info->size); |
| 153 | } |
| 154 | |
| 155 | /*----------------------------------------------------------------------- |
| 156 | */ |
| 157 | ulong flash_init (void) |
| 158 | { |
| 159 | ulong size = 0; |
| 160 | int i; |
| 161 | |
| 162 | /* Init: no FLASHes known */ |
| 163 | for (i = 0; i < CFG_MAX_FLASH_BANKS; ++i) { |
| 164 | flash_info[i].flash_id = FLASH_UNKNOWN; |
| 165 | } |
| 166 | |
| 167 | /* Static FLASH Bank configuration here (only one bank) */ |
| 168 | size = flash_get_size (CFG_FLASH_BASE, &flash_info[0]); |
| 169 | |
| 170 | if (flash_info[0].flash_id == FLASH_UNKNOWN || size == 0) { |
| 171 | printf ("## Unknown FLASH on Bank 0 - Size = 0x%08lx = %ld MB\n", |
| 172 | size, size >> 20); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * protect monitor and environment sectors |
| 177 | */ |
| 178 | flash_protect (FLAG_PROTECT_SET, |
| 179 | CFG_FLASH_BASE, |
| 180 | CFG_FLASH_BASE + monitor_flash_len - 1, |
| 181 | &flash_info[0]); |
| 182 | |
| 183 | flash_protect (FLAG_PROTECT_SET, |
Jean-Christophe PLAGNIOL-VILLARD | 0e8d158 | 2008-09-10 22:48:06 +0200 | [diff] [blame] | 184 | CONFIG_ENV_ADDR, |
| 185 | CONFIG_ENV_ADDR + CONFIG_ENV_SIZE - 1, &flash_info[0]); |
wdenk | 2d1a537 | 2004-02-23 19:30:57 +0000 | [diff] [blame] | 186 | |
| 187 | return size; |
| 188 | } |
| 189 | |
| 190 | /*----------------------------------------------------------------------- |
| 191 | */ |
| 192 | void flash_print_info (flash_info_t * info) |
| 193 | { |
| 194 | int i; |
| 195 | |
| 196 | if (info->flash_id == FLASH_UNKNOWN) { |
| 197 | printf ("missing or unknown FLASH type\n"); |
| 198 | return; |
| 199 | } |
| 200 | |
| 201 | switch (info->flash_id & FLASH_VENDMASK) { |
| 202 | case FLASH_MAN_AMD: |
| 203 | printf ("AMD "); |
| 204 | break; |
| 205 | case FLASH_MAN_FUJ: |
| 206 | printf ("Fujitsu "); |
| 207 | break; |
| 208 | default: |
| 209 | printf ("Unknown Vendor "); |
| 210 | break; |
| 211 | } |
| 212 | |
| 213 | switch (info->flash_id & FLASH_TYPEMASK) { |
| 214 | case FLASH_AMDL323B: |
| 215 | printf ("29DL323B (32 M, bottom sector)\n"); |
| 216 | break; |
| 217 | case (FLASH_AM160LV | FLASH_AM160B): |
| 218 | printf ("29LV160BE (1M x 16, bottom sector)\n"); |
| 219 | break; |
| 220 | default: |
| 221 | printf ("Unknown Chip Type\n"); |
| 222 | break; |
| 223 | } |
| 224 | |
| 225 | printf (" Size: %ld MB in %d Sectors\n", |
| 226 | info->size >> 20, info->sector_count); |
| 227 | printf (" Sector Start Addresses:"); |
| 228 | for (i = 0; i < info->sector_count; i++) { |
| 229 | if ((i % 4) == 0) |
| 230 | printf ("\n "); |
| 231 | printf (" S%02d @ 0x%08lX%s", i, |
| 232 | info->start[i], info->protect[i] ? " !" : " "); |
| 233 | } |
| 234 | printf ("\n"); |
| 235 | return; |
| 236 | } |
| 237 | |
| 238 | /*----------------------------------------------------------------------- |
| 239 | */ |
| 240 | int flash_check_protection (flash_info_t * info, int s_first, int s_last) |
| 241 | { |
| 242 | int sect, prot = 0; |
| 243 | |
| 244 | for (sect = s_first; sect <= s_last; sect++) |
| 245 | if (info->protect[sect]) |
| 246 | prot++; |
| 247 | if (prot) |
| 248 | printf ("- can't erase %d protected sectors\n", prot); |
| 249 | return prot; |
| 250 | } |
| 251 | |
| 252 | /*----------------------------------------------------------------------- |
| 253 | */ |
| 254 | int flash_check_erase_amd (ulong start) |
| 255 | { |
| 256 | __u16 v1, v2; |
| 257 | |
| 258 | v1 = *(volatile __u16 *) (start); |
| 259 | v2 = *(volatile __u16 *) (start); |
| 260 | |
| 261 | if (((v1 ^ v2) & toggling_bits) == toggling_bits) { |
| 262 | if (((v1 | v2) & DQ5) == DQ5) { |
| 263 | printf ("[DQ5] "); |
| 264 | /* OOPS: exceeded timing limits */ |
| 265 | |
| 266 | v1 = *(volatile __u16 *) (start); |
| 267 | v2 = *(volatile __u16 *) (start); |
| 268 | |
| 269 | if (((v1 ^ v2) & toggling_bits) == toggling_bits) { |
| 270 | |
| 271 | printf ("[%s] ", |
| 272 | ((toggling_bits & (DQ2 | DQ6)) == |
| 273 | (DQ2 | DQ6)) ? "DQ2,DQ6" : "DQ6"); |
| 274 | |
| 275 | /* OOPS: there is an erasure in progress, |
| 276 | * try to reset chip */ |
| 277 | *(volatile __u16 *) (start) = |
| 278 | (__u16) RESET_CMD; |
| 279 | |
| 280 | return 1; /* still busy */ |
| 281 | } |
| 282 | } |
| 283 | return 1; /* still busy */ |
| 284 | } |
| 285 | return 0; /* be free */ |
| 286 | } |
| 287 | |
| 288 | /*----------------------------------------------------------------------- |
| 289 | */ |
| 290 | int flash_erase (flash_info_t * info, int s_first, int s_last) |
| 291 | { |
| 292 | int flag, sect, setup_offset = 0; |
| 293 | int rc = ERR_OK; |
| 294 | |
| 295 | if (info->flash_id == FLASH_UNKNOWN) { |
| 296 | printf ("- missing\n"); |
| 297 | return ERR_UNKNOWN_FLASH_TYPE; |
| 298 | } |
| 299 | |
| 300 | if ((s_first < 0) || (s_first > s_last)) { |
| 301 | printf ("- no sectors to erase\n"); |
| 302 | return ERR_INVAL; |
| 303 | } |
| 304 | |
| 305 | if (flash_check_protection (info, s_first, s_last)) |
| 306 | return ERR_PROTECTED; |
| 307 | |
| 308 | switch (info->flash_id & FLASH_VENDMASK) { |
| 309 | case FLASH_MAN_FUJ: |
| 310 | case FLASH_MAN_AMD: |
| 311 | switch (info->flash_id & FLASH_TYPEMASK) { |
| 312 | case (FLASH_AM160LV | FLASH_AM160B): |
| 313 | setup_offset = UNLOCK_ADDR1; /* just the adress for setup_cmd differs */ |
| 314 | case FLASH_AMDL323B: |
wdenk | cd0a9de | 2004-02-23 20:48:38 +0000 | [diff] [blame] | 315 | /* |
wdenk | 2d1a537 | 2004-02-23 19:30:57 +0000 | [diff] [blame] | 316 | * Disable interrupts which might cause a timeout |
| 317 | * here. Remember that our exception vectors are |
| 318 | * at address 0 in the flash, and we don't want a |
| 319 | * (ticker) exception to happen while the flash |
| 320 | * chip is in programming mode. |
| 321 | */ |
| 322 | flag = disable_interrupts (); |
| 323 | /* Start erase on unprotected sectors */ |
| 324 | for (sect = s_first; sect <= s_last && !ctrlc (); |
| 325 | sect++) { |
| 326 | printf ("Erasing sector %2d ... ", sect); |
| 327 | |
| 328 | if (info->protect[sect] == 0) { |
| 329 | /* not protected */ |
| 330 | /* Write sector erase command sequence */ |
| 331 | WRITE_UNLOCK (info->start[0]); |
| 332 | *(volatile __u16 *) (info->start[0] + |
| 333 | setup_offset) = |
| 334 | (__u16) SETUP_CMD; |
| 335 | WRITE_UNLOCK (info->start[0]); |
| 336 | *(volatile __u16 *) (info-> |
| 337 | start[sect]) = |
| 338 | (__u16) SECERASE_CMD; |
| 339 | |
| 340 | /* wait some time */ |
| 341 | reset_timer_masked (); |
| 342 | while (get_timer_masked () < 1000) { |
| 343 | } |
| 344 | |
| 345 | /* arm simple, non interrupt dependent timer */ |
| 346 | reset_timer_masked (); |
| 347 | while (flash_check_erase_amd (info->start[sect])) { |
| 348 | if (get_timer_masked () > CFG_FLASH_ERASE_TOUT) { |
| 349 | printf ("timeout!\n"); |
| 350 | /* OOPS: reach timeout, |
| 351 | * try to reset chip |
| 352 | */ |
| 353 | *(volatile __u16 *) (info-> start[sect]) = (__u16) RESET_CMD; |
| 354 | rc = ERR_TIMOUT; |
| 355 | goto outahere_323B; |
| 356 | } |
| 357 | } |
| 358 | printf ("ok.\n"); |
| 359 | } else { |
| 360 | printf ("protected!\n"); |
| 361 | } |
| 362 | } |
| 363 | if (ctrlc ()) |
| 364 | printf ("User Interrupt!\n"); |
| 365 | outahere_323B: |
| 366 | /* allow flash to settle - wait 10 ms */ |
| 367 | udelay_masked (10000); |
| 368 | if (flag) |
| 369 | enable_interrupts (); |
| 370 | return rc; |
| 371 | default: |
| 372 | printf ("- unknown chip type\n"); |
| 373 | return ERR_UNKNOWN_FLASH_TYPE; |
| 374 | } |
| 375 | break; |
| 376 | default: |
| 377 | printf ("- unknown vendor "); |
| 378 | return ERR_UNKNOWN_FLASH_VENDOR; |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | /*----------------------------------------------------------------------- |
| 383 | */ |
| 384 | int flash_check_write_amd (ulong dest) |
| 385 | { |
| 386 | __u16 v1, v2; |
| 387 | |
| 388 | v1 = *(volatile __u16 *) (dest); |
| 389 | v2 = *(volatile __u16 *) (dest); |
| 390 | |
| 391 | /* DQ6 toggles during write */ |
| 392 | if (((v1 ^ v2) & DQ6) == DQ6) { |
| 393 | if (((v1 | v2) & DQ5) == DQ5) { |
| 394 | printf ("[DQ5] @ %08lX\n", dest); |
| 395 | |
| 396 | /* OOPS: exceeded timing limits, |
| 397 | * try to reset chip */ |
| 398 | *(volatile __u16 *) (dest) = (__u16) RESET_CMD; |
| 399 | return 0; /* be free */ |
| 400 | } |
| 401 | return 1; /* still busy */ |
| 402 | } |
| 403 | |
| 404 | return 0; /* be free */ |
| 405 | } |
| 406 | |
| 407 | /*----------------------------------------------------------------------- |
| 408 | * Copy memory to flash |
| 409 | */ |
| 410 | static int write_word (flash_info_t * info, ulong dest, ushort data) |
| 411 | { |
| 412 | int rc = ERR_OK; |
| 413 | int flag; |
| 414 | |
| 415 | /* Check if Flash is (sufficiently) erased */ |
| 416 | if ((*(__u16 *) (dest) & data) != data) |
| 417 | return ERR_NOT_ERASED; |
| 418 | |
wdenk | cd0a9de | 2004-02-23 20:48:38 +0000 | [diff] [blame] | 419 | /* |
wdenk | 2d1a537 | 2004-02-23 19:30:57 +0000 | [diff] [blame] | 420 | * Disable interrupts which might cause a timeout |
| 421 | * here. Remember that our exception vectors are |
| 422 | * at address 0 in the flash, and we don't want a |
| 423 | * (ticker) exception to happen while the flash |
| 424 | * chip is in programming mode. |
| 425 | */ |
| 426 | flag = disable_interrupts (); |
| 427 | |
| 428 | /* Write program command sequence */ |
| 429 | WRITE_UNLOCK (info->start[0]); |
| 430 | |
| 431 | /* Flash dependend program seqence */ |
| 432 | switch (info->flash_id & FLASH_VENDMASK) { |
| 433 | case FLASH_MAN_FUJ: |
| 434 | case FLASH_MAN_AMD: |
| 435 | switch (info->flash_id & FLASH_TYPEMASK) { |
| 436 | case (FLASH_AM160LV | FLASH_AM160B): |
| 437 | *(volatile __u16 *) (info->start[0] + UNLOCK_ADDR1) = |
| 438 | (__u16) PROG_CMD; |
| 439 | *(volatile __u16 *) (dest) = (__u16) data; |
| 440 | break; |
| 441 | case FLASH_AMDL323B: |
| 442 | *(volatile __u16 *) (dest) = (__u16) PROG_CMD; |
| 443 | *(volatile __u16 *) (dest) = (__u16) data; |
| 444 | break; |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | /* arm simple, non interrupt dependent timer */ |
| 449 | reset_timer_masked (); |
| 450 | |
| 451 | while (flash_check_write_amd (dest)) { |
| 452 | if (get_timer_masked () > CFG_FLASH_WRITE_TOUT) { |
| 453 | printf ("timeout! @ %08lX\n", dest); |
| 454 | /* OOPS: reach timeout, |
| 455 | * try to reset chip */ |
| 456 | *(volatile __u16 *) (dest) = (__u16) RESET_CMD; |
| 457 | |
| 458 | rc = ERR_TIMOUT; |
| 459 | goto outahere_323B; |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | /* Check if Flash was (accurately) written */ |
| 464 | if (*(__u16 *) (dest) != data) |
| 465 | rc = ERR_PROG_ERROR; |
| 466 | |
| 467 | outahere_323B: |
| 468 | if (flag) |
| 469 | enable_interrupts (); |
| 470 | return rc; |
| 471 | } |
| 472 | |
| 473 | /*----------------------------------------------------------------------- |
| 474 | * Copy memory to flash. |
| 475 | */ |
| 476 | int write_buff (flash_info_t * info, uchar * src, ulong addr, ulong cnt) |
| 477 | { |
| 478 | ulong cp, wp; |
| 479 | ushort data; |
| 480 | int l; |
| 481 | int i, rc; |
| 482 | |
| 483 | wp = (addr & ~1); /* get lower word aligned address */ |
| 484 | |
| 485 | /* |
| 486 | * handle unaligned start bytes |
| 487 | */ |
| 488 | if ((l = addr - wp) != 0) { |
| 489 | data = 0; |
| 490 | for (i = 0, cp = wp; i < l; ++i, ++cp) { |
| 491 | data = (data >> 8) | (*(uchar *) cp << 8); |
| 492 | } |
| 493 | for (; i < 2 && cnt > 0; ++i) { |
| 494 | data = (data >> 8) | (*src++ << 8); |
| 495 | --cnt; |
| 496 | ++cp; |
| 497 | } |
| 498 | for (; cnt == 0 && i < 2; ++i, ++cp) { |
| 499 | data = (data >> 8) | (*(uchar *) cp << 8); |
| 500 | } |
| 501 | |
| 502 | if ((rc = write_word (info, wp, data)) != 0) { |
| 503 | return (rc); |
| 504 | } |
| 505 | wp += 2; |
| 506 | } |
| 507 | |
| 508 | /* |
| 509 | * handle word aligned part |
| 510 | */ |
| 511 | while (cnt >= 2) { |
| 512 | data = *((ushort *) src); |
| 513 | if ((rc = write_word (info, wp, data)) != 0) |
| 514 | return (rc); |
| 515 | src += 2; |
| 516 | wp += 2; |
| 517 | cnt -= 2; |
| 518 | } |
| 519 | |
| 520 | if (cnt == 0) |
| 521 | return ERR_OK; |
| 522 | |
| 523 | /* |
| 524 | * handle unaligned tail bytes |
| 525 | */ |
| 526 | data = 0; |
| 527 | for (i = 0, cp = wp; i < 2 && cnt > 0; ++i, ++cp) { |
| 528 | data = (data >> 8) | (*src++ << 8); |
| 529 | --cnt; |
| 530 | } |
| 531 | for (; i < 2; ++i, ++cp) { |
| 532 | data = (data >> 8) | (*(uchar *) cp << 8); |
| 533 | } |
| 534 | |
| 535 | return write_word (info, wp, data); |
| 536 | } |