software/SCSI2SD/src/scsi.c

   1 //      Copyright (C) 2014 Michael McMaster <michael@codesrc.com>\r
   2 //\r
   3 //      This file is part of SCSI2SD.\r
   4 //\r
   5 //      SCSI2SD is free software: you can redistribute it and/or modify\r
   6 //      it under the terms of the GNU General Public License as published by\r
   7 //      the Free Software Foundation, either version 3 of the License, or\r
   8 //      (at your option) any later version.\r
   9 //\r
  10 //      SCSI2SD is distributed in the hope that it will be useful,\r
  11 //      but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  12 //      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  13 //      GNU General Public License for more details.\r
  14 //\r
  15 //      You should have received a copy of the GNU General Public License\r
  16 //      along with SCSI2SD.  If not, see <http://www.gnu.org/licenses/>.\r
  17 #pragma GCC push_options\r
  18 #pragma GCC optimize("-flto")\r
  19 \r
  20 #include "device.h"\r
  21 #include "scsi.h"\r
  22 #include "scsiPhy.h"\r
  23 #include "config.h"\r
  24 #include "bits.h"\r
  25 #include "diagnostic.h"\r
  26 #include "disk.h"\r
  27 #include "inquiry.h"\r
  28 #include "led.h"\r
  29 #include "mode.h"\r
  30 #include "disk.h"\r
  31 #include "time.h"\r
  32 #include "cdrom.h"\r
  33 #include "debug.h"\r
  34 \r
  35 #include <string.h>\r
  36 \r
  37 // Global SCSI device state.\r
  38 ScsiDevice scsiDev;\r
  39 \r
  40 static void enter_SelectionPhase(void);\r
  41 static void process_SelectionPhase(void);\r
  42 static void enter_BusFree(void);\r
  43 static void enter_MessageIn(uint8 message);\r
  44 static void enter_Status(uint8 status);\r
  45 static void enter_DataIn(int len);\r
  46 static void process_DataIn(void);\r
  47 static void process_DataOut(void);\r
  48 static void process_Command(void);\r
  49 \r
  50 static void doReserveRelease(void);\r
  51 \r
  52 static void enter_BusFree()\r
  53 {\r
  54         // This delay probably isn't needed for most SCSI hosts, but it won't\r
  55         // hurt either. It's possible some of the samplers needed this delay.\r
  56         if (scsiDev.compatMode)\r
  57         {\r
  58                 CyDelayUs(2);\r
  59         }\r
  60 \r
  61         if (scsiDev.status != GOOD && isDebugEnabled())\r
  62         {\r
  63                 // We want to capture debug information for failure cases.\r
  64                 CyDelay(64);\r
  65         }\r
  66 \r
  67         SCSI_ClearPin(SCSI_Out_BSY);\r
  68         // We now have a Bus Clear Delay of 800ns to release remaining signals.\r
  69         SCSI_CTL_PHASE_Write(0);\r
  70 \r
  71         // Wait for the initiator to cease driving signals\r
  72         // Bus settle delay + bus clear delay = 1200ns\r
  73         CyDelayUs(2);\r
  74 \r
  75         ledOff();\r
  76         scsiDev.phase = BUS_FREE;\r
  77 }\r
  78 \r
  79 static void enter_MessageIn(uint8 message)\r
  80 {\r
  81         scsiDev.msgIn = message;\r
  82         scsiDev.phase = MESSAGE_IN;\r
  83 }\r
  84 \r
  85 void process_MessageIn()\r
  86 {\r
  87         scsiEnterPhase(MESSAGE_IN);\r
  88         scsiWriteByte(scsiDev.msgIn);\r
  89 \r
  90         if (unlikely(scsiDev.atnFlag))\r
  91         {\r
  92                 // If there was a parity error, we go\r
  93                 // back to MESSAGE_OUT first, get out parity error message, then come\r
  94                 // back here.\r
  95         }\r
  96         else if ((scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE) ||\r
  97                 (scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG))\r
  98         {\r
  99                 // Go back to the command phase and start again.\r
 100                 scsiDev.phase = COMMAND;\r
 101                 scsiDev.parityError = 0;\r
 102                 scsiDev.dataPtr = 0;\r
 103                 scsiDev.savedDataPtr = 0;\r
 104                 scsiDev.dataLen = 0;\r
 105                 scsiDev.status = GOOD;\r
 106                 transfer.blocks = 0;\r
 107                 transfer.currentBlock = 0;\r
 108         }\r
 109         else /*if (scsiDev.msgIn == MSG_COMMAND_COMPLETE)*/\r
 110         {\r
 111                 enter_BusFree();\r
 112         }\r
 113 }\r
 114 \r
 115 static void messageReject()\r
 116 {\r
 117         scsiEnterPhase(MESSAGE_IN);\r
 118         scsiWriteByte(MSG_REJECT);\r
 119 }\r
 120 \r
 121 static void enter_Status(uint8 status)\r
 122 {\r
 123         scsiDev.status = status;\r
 124         scsiDev.phase = STATUS;\r
 125 \r
 126         scsiDev.lastStatus = scsiDev.status;\r
 127         scsiDev.lastSense = scsiDev.target->sense.code;\r
 128         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 129 }\r
 130 \r
 131 void process_Status()\r
 132 {\r
 133         scsiEnterPhase(STATUS);\r
 134 \r
 135         uint8 message;\r
 136 \r
 137         uint8 control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 138         if ((scsiDev.status == GOOD) && (control & 0x01))\r
 139         {\r
 140                 // Linked command.\r
 141                 scsiDev.status = INTERMEDIATE;\r
 142                 if (control & 0x02)\r
 143                 {\r
 144                         message = MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG;\r
 145                 }\r
 146                 else\r
 147                 {\r
 148                         message = MSG_LINKED_COMMAND_COMPLETE;\r
 149                 }\r
 150         }\r
 151         else\r
 152         {\r
 153                 message = MSG_COMMAND_COMPLETE;\r
 154         }\r
 155         scsiWriteByte(scsiDev.status);\r
 156 \r
 157         scsiDev.lastStatus = scsiDev.status;\r
 158         scsiDev.lastSense = scsiDev.target->sense.code;\r
 159         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 160 \r
 161 \r
 162         // Command Complete occurs AFTER a valid status has been\r
 163         // sent. then we go bus-free.\r
 164         enter_MessageIn(message);\r
 165 }\r
 166 \r
 167 static void enter_DataIn(int len)\r
 168 {\r
 169         scsiDev.dataLen = len;\r
 170         scsiDev.phase = DATA_IN;\r
 171 }\r
 172 \r
 173 static void process_DataIn()\r
 174 {\r
 175         uint32 len;\r
 176 \r
 177         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 178         {\r
 179                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 180         }\r
 181 \r
 182         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 183         if (len > 0)\r
 184         {\r
 185                 scsiEnterPhase(DATA_IN);\r
 186                 scsiWrite(scsiDev.data + scsiDev.dataPtr, len);\r
 187                 scsiDev.dataPtr += len;\r
 188         }\r
 189 \r
 190         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 191                 (transfer.currentBlock == transfer.blocks))\r
 192         {\r
 193                 enter_Status(GOOD);\r
 194         }\r
 195 }\r
 196 \r
 197 static void process_DataOut()\r
 198 {\r
 199         uint32 len;\r
 200 \r
 201         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 202         {\r
 203                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 204         }\r
 205 \r
 206         scsiDev.parityError = 0;\r
 207         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 208         if (len > 0)\r
 209         {\r
 210                 scsiEnterPhase(DATA_OUT);\r
 211 \r
 212                 scsiRead(scsiDev.data + scsiDev.dataPtr, len);\r
 213                 scsiDev.dataPtr += len;\r
 214 \r
 215                 if (scsiDev.parityError &&\r
 216                         (scsiDev.target->cfg->flags & CONFIG_ENABLE_PARITY) &&\r
 217                         !scsiDev.compatMode)\r
 218                 {\r
 219                         scsiDev.target->sense.code = ABORTED_COMMAND;\r
 220                         scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 221                         enter_Status(CHECK_CONDITION);\r
 222                 }\r
 223         }\r
 224 \r
 225         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 226                 (transfer.currentBlock == transfer.blocks))\r
 227         {\r
 228                 if (scsiDev.postDataOutHook != NULL)\r
 229                 {\r
 230                         scsiDev.postDataOutHook();\r
 231                 }\r
 232                 else\r
 233                 {\r
 234                         enter_Status(GOOD);\r
 235                 }\r
 236         }\r
 237 }\r
 238 \r
 239 static const uint8 CmdGroupBytes[8] = {6, 10, 10, 6, 6, 12, 6, 6};\r
 240 static void process_Command()\r
 241 {\r
 242         int group;\r
 243         uint8 command;\r
 244         uint8 control;\r
 245 \r
 246         scsiEnterPhase(COMMAND);\r
 247         scsiDev.parityError = 0;\r
 248 \r
 249         memset(scsiDev.cdb, 0, sizeof(scsiDev.cdb));\r
 250         scsiDev.cdb[0] = scsiReadByte();\r
 251 \r
 252         group = scsiDev.cdb[0] >> 5;\r
 253         scsiDev.cdbLen = CmdGroupBytes[group];\r
 254         scsiRead(scsiDev.cdb + 1, scsiDev.cdbLen - 1);\r
 255 \r
 256         command = scsiDev.cdb[0];\r
 257 \r
 258         // Prefer LUN's set by IDENTIFY messages for newer hosts.\r
 259         if (scsiDev.lun < 0)\r
 260         {\r
 261                 scsiDev.lun = scsiDev.cdb[1] >> 5;\r
 262         }\r
 263 \r
 264         control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 265 \r
 266         scsiDev.cmdCount++;\r
 267 \r
 268         if (unlikely(scsiDev.resetFlag))\r
 269         {\r
 270                 // Don't log bogus commands\r
 271                 scsiDev.cmdCount--;\r
 272                 memset(scsiDev.cdb, 0xff, sizeof(scsiDev.cdb));\r
 273                 return;\r
 274         }\r
 275         else if (scsiDev.parityError &&\r
 276                 (scsiDev.target->cfg->flags & CONFIG_ENABLE_PARITY) &&\r
 277                 !scsiDev.compatMode)\r
 278         {\r
 279                 scsiDev.target->sense.code = ABORTED_COMMAND;\r
 280                 scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 281                 enter_Status(CHECK_CONDITION);\r
 282         }\r
 283         else if ((control & 0x02) && ((control & 0x01) == 0))\r
 284         {\r
 285                 // FLAG set without LINK flag.\r
 286                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 287                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 288                 enter_Status(CHECK_CONDITION);\r
 289         }\r
 290         else if (command == 0x12)\r
 291         {\r
 292                 scsiInquiry();\r
 293         }\r
 294         else if (command == 0x03)\r
 295         {\r
 296                 // REQUEST SENSE\r
 297                 uint32 allocLength = scsiDev.cdb[4];\r
 298 \r
 299                 // As specified by the SASI and SCSI1 standard.\r
 300                 // Newer initiators won't be specifying 0 anyway.\r
 301                 if (allocLength == 0) allocLength = 4;\r
 302 \r
 303                 memset(scsiDev.data, 0, 256); // Max possible alloc length\r
 304                 scsiDev.data[0] = 0xF0;\r
 305                 scsiDev.data[2] = scsiDev.target->sense.code & 0x0F;\r
 306 \r
 307                 scsiDev.data[3] = transfer.lba >> 24;\r
 308                 scsiDev.data[4] = transfer.lba >> 16;\r
 309                 scsiDev.data[5] = transfer.lba >> 8;\r
 310                 scsiDev.data[6] = transfer.lba;\r
 311 \r
 312                 // Additional bytes if there are errors to report\r
 313                 scsiDev.data[7] = 10; // additional length\r
 314                 scsiDev.data[12] = scsiDev.target->sense.asc >> 8;\r
 315                 scsiDev.data[13] = scsiDev.target->sense.asc;\r
 316 \r
 317                 // Silently truncate results. SCSI-2 spec 8.2.14.\r
 318                 enter_DataIn(allocLength);\r
 319 \r
 320                 // This is a good time to clear out old sense information.\r
 321                 scsiDev.target->sense.code = NO_SENSE;\r
 322                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 323         }\r
 324         // Some old SCSI drivers do NOT properly support\r
 325         // unitAttention. eg. the Mac Plus would trigger a SCSI reset\r
 326         // on receiving the unit attention response on boot, thus\r
 327         // triggering another unit attention condition.\r
 328         else if (scsiDev.target->unitAttention &&\r
 329                 (scsiDev.target->cfg->flags & CONFIG_ENABLE_UNIT_ATTENTION))\r
 330         {\r
 331                 scsiDev.target->sense.code = UNIT_ATTENTION;\r
 332                 scsiDev.target->sense.asc = scsiDev.target->unitAttention;\r
 333 \r
 334                 // If initiator doesn't do REQUEST SENSE for the next command, then\r
 335                 // data is lost.\r
 336                 scsiDev.target->unitAttention = 0;\r
 337 \r
 338                 enter_Status(CHECK_CONDITION);\r
 339         }\r
 340         else if (scsiDev.lun)\r
 341         {\r
 342                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 343                 scsiDev.target->sense.asc = LOGICAL_UNIT_NOT_SUPPORTED;\r
 344                 enter_Status(CHECK_CONDITION);\r
 345         }\r
 346         else if (command == 0x17 || command == 0x16)\r
 347         {\r
 348                 doReserveRelease();\r
 349         }\r
 350         else if ((scsiDev.target->reservedId >= 0) &&\r
 351                 (scsiDev.target->reservedId != scsiDev.initiatorId))\r
 352         {\r
 353                 enter_Status(CONFLICT);\r
 354         }\r
 355         else if (scsiDiskCommand())\r
 356         {\r
 357                 // Already handled.\r
 358                 // check for the performance-critical read/write\r
 359                 // commands ASAP.\r
 360         }\r
 361         else if (command == 0x1C)\r
 362         {\r
 363                 scsiReceiveDiagnostic();\r
 364         }\r
 365         else if (command == 0x1D)\r
 366         {\r
 367                 scsiSendDiagnostic();\r
 368         }\r
 369         else if (command == 0x3B)\r
 370         {\r
 371                 scsiWriteBuffer();\r
 372         }\r
 373         else if (command == 0x3C)\r
 374         {\r
 375                 scsiReadBuffer();\r
 376         }\r
 377         else if (\r
 378                 !scsiCDRomCommand() &&\r
 379                 !scsiModeCommand())\r
 380         {\r
 381                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 382                 scsiDev.target->sense.asc = INVALID_COMMAND_OPERATION_CODE;\r
 383                 enter_Status(CHECK_CONDITION);\r
 384         }\r
 385 \r
 386         // Successful\r
 387         if (scsiDev.phase == COMMAND) // No status set, and not in DATA_IN\r
 388         {\r
 389                 enter_Status(GOOD);\r
 390         }\r
 391 \r
 392 }\r
 393 \r
 394 static void doReserveRelease()\r
 395 {\r
 396         int extentReservation = scsiDev.cdb[1] & 1;\r
 397         int thirdPty = scsiDev.cdb[1] & 0x10;\r
 398         int thirdPtyId = (scsiDev.cdb[1] >> 1) & 0x7;\r
 399         uint8 command = scsiDev.cdb[0];\r
 400 \r
 401         int canRelease =\r
 402                 (!thirdPty && (scsiDev.initiatorId == scsiDev.target->reservedId)) ||\r
 403                         (thirdPty &&\r
 404                                 (scsiDev.target->reserverId == scsiDev.initiatorId) &&\r
 405                                 (scsiDev.target->reservedId == thirdPtyId)\r
 406                         );\r
 407 \r
 408         if (extentReservation)\r
 409         {\r
 410                 // Not supported.\r
 411                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 412                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 413                 enter_Status(CHECK_CONDITION);\r
 414         }\r
 415         else if (command == 0x17) // release\r
 416         {\r
 417                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 418                 {\r
 419                         scsiDev.target->reservedId = -1;\r
 420                         scsiDev.target->reserverId = -1;\r
 421                 }\r
 422                 else\r
 423                 {\r
 424                         enter_Status(CONFLICT);\r
 425                 }\r
 426         }\r
 427         else // assume reserve.\r
 428         {\r
 429                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 430                 {\r
 431                         scsiDev.target->reserverId = scsiDev.initiatorId;\r
 432                         if (thirdPty)\r
 433                         {\r
 434                                 scsiDev.target->reservedId = thirdPtyId;\r
 435                         }\r
 436                         else\r
 437                         {\r
 438                                 scsiDev.target->reservedId = scsiDev.initiatorId;\r
 439                         }\r
 440                 }\r
 441                 else\r
 442                 {\r
 443                         // Already reserved by someone else!\r
 444                         enter_Status(CONFLICT);\r
 445                 }\r
 446         }\r
 447 }\r
 448 \r
 449 static void scsiReset()\r
 450 {\r
 451         scsiDev.rstCount++;\r
 452         ledOff();\r
 453 \r
 454         scsiPhyReset();\r
 455         SCSI_Out_Ctl_Write(0);\r
 456 \r
 457         scsiDev.parityError = 0;\r
 458         scsiDev.phase = BUS_FREE;\r
 459         scsiDev.atnFlag = 0;\r
 460         scsiDev.resetFlag = 0;\r
 461         scsiDev.lun = -1;\r
 462 \r
 463         if (scsiDev.target)\r
 464         {\r
 465                 if (scsiDev.target->unitAttention != POWER_ON_RESET)\r
 466                 {\r
 467                         scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 468                 }\r
 469                 scsiDev.target->reservedId = -1;\r
 470                 scsiDev.target->reserverId = -1;\r
 471                 scsiDev.target->sense.code = NO_SENSE;\r
 472                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 473         }\r
 474         scsiDev.target = NULL;\r
 475         scsiDiskReset();\r
 476 \r
 477         scsiDev.postDataOutHook = NULL;\r
 478 \r
 479         // Sleep to allow the bus to settle down a bit.\r
 480         // We must be ready again within the "Reset to selection time" of\r
 481         // 250ms.\r
 482         // There is no guarantee that the RST line will be negated by then.\r
 483         // NOTE: We could be connected and powered by USB for configuration,\r
 484         // in which case TERMPWR cannot be supplied, and reset will ALWAYS\r
 485         // be true. Therefore, the sleep here must be slow to avoid slowing\r
 486         // USB comms\r
 487         CyDelay(1); // 1ms.\r
 488 }\r
 489 \r
 490 static void enter_SelectionPhase()\r
 491 {\r
 492         // Ignore stale versions of this flag, but ensure we know the\r
 493         // current value if the flag is still set.\r
 494         scsiDev.atnFlag = 0;\r
 495         scsiDev.parityError = 0;\r
 496         scsiDev.dataPtr = 0;\r
 497         scsiDev.savedDataPtr = 0;\r
 498         scsiDev.dataLen = 0;\r
 499         scsiDev.status = GOOD;\r
 500         scsiDev.phase = SELECTION;\r
 501         scsiDev.lun = -1;\r
 502         scsiDev.discPriv = 0;\r
 503         scsiDev.compatMode = 0;\r
 504 \r
 505         scsiDev.initiatorId = -1;\r
 506         scsiDev.target = NULL;\r
 507 \r
 508         transfer.blocks = 0;\r
 509         transfer.currentBlock = 0;\r
 510 \r
 511         scsiDev.postDataOutHook = NULL;\r
 512 }\r
 513 \r
 514 static void process_SelectionPhase()\r
 515 {\r
 516         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 517         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 518 \r
 519         // Only read these pins AFTER SEL and BSY - we don't want to catch them\r
 520         // during a transition period.\r
 521         uint8 mask = scsiReadDBxPins();\r
 522         int maskBitCount = countBits(mask);\r
 523         int goodParity = (Lookup_OddParity[mask] == SCSI_ReadPin(SCSI_In_DBP));\r
 524         int atnFlag = SCSI_ReadFilt(SCSI_Filt_ATN);\r
 525 \r
 526         int tgtIndex;\r
 527         TargetState* target = NULL;\r
 528         for (tgtIndex = 0; tgtIndex < MAX_SCSI_TARGETS; ++tgtIndex)\r
 529         {\r
 530                 if (mask & (1 << scsiDev.targets[tgtIndex].targetId))\r
 531                 {\r
 532                         target = &scsiDev.targets[tgtIndex];\r
 533                         break;\r
 534                 }\r
 535         }\r
 536         if (!bsy && sel &&\r
 537                 target &&\r
 538                 (goodParity || !(target->cfg->flags & CONFIG_ENABLE_PARITY) || !atnFlag) &&\r
 539                 likely(maskBitCount <= 2))\r
 540         {\r
 541                 scsiDev.target = target;\r
 542 \r
 543                 // Do we enter MESSAGE OUT immediately ? SCSI 1 and 2 standards says\r
 544                 // move to MESSAGE OUT if ATN is true before we assert BSY.\r
 545                 // The initiator should assert ATN with SEL.\r
 546                 scsiDev.atnFlag = atnFlag;\r
 547 \r
 548                 // Unit attention breaks many older SCSI hosts. Disable it completely\r
 549                 // for SCSI-1 (and older) hosts, regardless of our configured setting.\r
 550                 // Enable the compatability mode also as many SASI and SCSI1\r
 551                 // controllers don't generate parity bits.\r
 552                 if (!scsiDev.atnFlag)\r
 553                 {\r
 554                         target->unitAttention = 0;\r
 555                         scsiDev.compatMode = 1;\r
 556                 }\r
 557 \r
 558                 // We've been selected!\r
 559                 // Assert BSY - Selection success!\r
 560                 // must happen within 200us (Selection abort time) of seeing our\r
 561                 // ID + SEL.\r
 562                 // (Note: the initiator will be waiting the "Selection time-out delay"\r
 563                 // for our BSY response, which is actually a very generous 250ms)\r
 564                 SCSI_SetPin(SCSI_Out_BSY);\r
 565                 ledOn();\r
 566 \r
 567                 scsiDev.selCount++;\r
 568 \r
 569                 // Wait until the end of the selection phase.\r
 570                 while (likely(!scsiDev.resetFlag))\r
 571                 {\r
 572                         if (!SCSI_ReadFilt(SCSI_Filt_SEL))\r
 573                         {\r
 574                                 break;\r
 575                         }\r
 576                 }\r
 577 \r
 578                 // Save our initiator now that we're no longer in a time-critical\r
 579                 // section.\r
 580                 // SCSI1/SASI initiators may not set their own ID.\r
 581                 {\r
 582                         int i;\r
 583                         uint8_t initiatorMask = mask ^ (1 << target->targetId);\r
 584                         scsiDev.initiatorId = -1;\r
 585                         for (i = 0; i < 8; ++i)\r
 586                         {\r
 587                                 if (initiatorMask & (1 << i))\r
 588                                 {\r
 589                                         scsiDev.initiatorId = i;\r
 590                                         break;\r
 591                                 }\r
 592                         }\r
 593                 }\r
 594 \r
 595                 scsiDev.phase = COMMAND;\r
 596         }\r
 597         else if (!sel)\r
 598         {\r
 599                 scsiDev.phase = BUS_BUSY;\r
 600         }\r
 601 }\r
 602 \r
 603 static void process_MessageOut()\r
 604 {\r
 605         scsiEnterPhase(MESSAGE_OUT);\r
 606 \r
 607         scsiDev.atnFlag = 0;\r
 608         scsiDev.parityError = 0;\r
 609         scsiDev.msgOut = scsiReadByte();\r
 610         scsiDev.msgCount++;\r
 611 \r
 612         if (scsiDev.parityError &&\r
 613                 (scsiDev.target->cfg->flags & CONFIG_ENABLE_PARITY) &&\r
 614                 !scsiDev.compatMode)\r
 615         {\r
 616                 // Skip the remaining message bytes, and then start the MESSAGE_OUT\r
 617                 // phase again from the start. The initiator will re-send the\r
 618                 // same set of messages.\r
 619                 while (SCSI_ReadFilt(SCSI_Filt_ATN) && !scsiDev.resetFlag)\r
 620                 {\r
 621                         scsiReadByte();\r
 622                 }\r
 623 \r
 624                 // Go-back and try the message again.\r
 625                 scsiDev.atnFlag = 1;\r
 626                 scsiDev.parityError = 0;\r
 627         }\r
 628         else if (scsiDev.msgOut == 0x00)\r
 629         {\r
 630                 // COMMAND COMPLETE. but why would the target be receiving this ? nfi.\r
 631                 enter_BusFree();\r
 632         }\r
 633         else if (scsiDev.msgOut == 0x06)\r
 634         {\r
 635                 // ABORT\r
 636                 scsiDiskReset();\r
 637                 enter_BusFree();\r
 638         }\r
 639         else if (scsiDev.msgOut == 0x0C)\r
 640         {\r
 641                 // BUS DEVICE RESET\r
 642 \r
 643                 scsiDiskReset();\r
 644 \r
 645                 scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 646 \r
 647                 // ANY initiator can reset the reservation state via this message.\r
 648                 scsiDev.target->reservedId = -1;\r
 649                 scsiDev.target->reserverId = -1;\r
 650                 enter_BusFree();\r
 651         }\r
 652         else if (scsiDev.msgOut == 0x05)\r
 653         {\r
 654                 // Initiate Detected Error\r
 655                 // Ignore for now\r
 656         }\r
 657         else if (scsiDev.msgOut == 0x0F)\r
 658         {\r
 659                 // INITIATE RECOVERY\r
 660                 // Ignore for now\r
 661         }\r
 662         else if (scsiDev.msgOut == 0x10)\r
 663         {\r
 664                 // RELEASE RECOVERY\r
 665                 // Ignore for now\r
 666                 enter_BusFree();\r
 667         }\r
 668         else if (scsiDev.msgOut == MSG_REJECT)\r
 669         {\r
 670                 // Message Reject\r
 671                 // Oh well.\r
 672                 scsiDev.resetFlag = 1;\r
 673         }\r
 674         else if (scsiDev.msgOut == 0x08)\r
 675         {\r
 676                 // NOP\r
 677         }\r
 678         else if (scsiDev.msgOut == 0x09)\r
 679         {\r
 680                 // Message Parity Error\r
 681                 // Go back and re-send the last message.\r
 682                 scsiDev.phase = MESSAGE_IN;\r
 683         }\r
 684         else if (scsiDev.msgOut & 0x80) // 0x80 -> 0xFF\r
 685         {\r
 686                 // IDENTIFY\r
 687                 if ((scsiDev.msgOut & 0x18) || // Reserved bits set.\r
 688                         (scsiDev.msgOut & 0x20))  // We don't have any target routines!\r
 689                 {\r
 690                         messageReject();\r
 691                 }\r
 692 \r
 693                 scsiDev.lun = scsiDev.msgOut & 0x7;\r
 694                 scsiDev.discPriv = \r
 695                         ((scsiDev.msgOut & 0x40) && (scsiDev.initiatorId >= 0))\r
 696                                 ? 1 : 0;\r
 697         }\r
 698         else if (scsiDev.msgOut >= 0x20 && scsiDev.msgOut <= 0x2F)\r
 699         {\r
 700                 // Two byte message. We don't support these. read and discard.\r
 701                 scsiReadByte();\r
 702         }\r
 703         else if (scsiDev.msgOut == 0x01)\r
 704         {\r
 705                 int i;\r
 706 \r
 707                 // Extended message.\r
 708                 int msgLen = scsiReadByte();\r
 709                 if (msgLen == 0) msgLen = 256;\r
 710                 uint8_t extmsg[256];\r
 711                 for (i = 0; i < msgLen && !scsiDev.resetFlag; ++i)\r
 712                 {\r
 713                         // Discard bytes.\r
 714                         extmsg[i] = scsiReadByte();\r
 715                 }\r
 716                 \r
 717                 if (extmsg[0] == 3 && msgLen == 2) // Wide Data Request\r
 718                 {\r
 719                         // Negotiate down to 8bit\r
 720                         scsiEnterPhase(MESSAGE_IN);\r
 721                         static const uint8_t WDTR[] = {0x01, 0x02, 0x03, 0x00};\r
 722                         scsiWrite(WDTR, sizeof(WDTR));\r
 723                 }\r
 724                 else if (extmsg[0] == 1 && msgLen == 5) // Synchronous data request\r
 725                 {\r
 726                         // Negotiate back to async\r
 727                         scsiEnterPhase(MESSAGE_IN);\r
 728                         static const uint8_t SDTR[] = {0x01, 0x03, 0x01, 0x00, 0x00};\r
 729                         scsiWrite(SDTR, sizeof(SDTR));\r
 730                 }\r
 731                 else\r
 732                 {\r
 733                         // Not supported\r
 734                         messageReject();\r
 735                 }\r
 736         }\r
 737         else\r
 738         {\r
 739                 messageReject();\r
 740         }\r
 741 \r
 742         // Re-check the ATN flag in case it stays asserted.\r
 743         scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 744 }\r
 745 \r
 746 void scsiPoll(void)\r
 747 {\r
 748         if (unlikely(scsiDev.resetFlag))\r
 749         {\r
 750                 scsiReset();\r
 751                 if ((scsiDev.resetFlag = SCSI_ReadFilt(SCSI_Filt_RST)))\r
 752                 {\r
 753                         // Still in reset phase. Do not try and process any commands.\r
 754                         return;\r
 755                 }\r
 756         }\r
 757 \r
 758         switch (scsiDev.phase)\r
 759         {\r
 760         case BUS_FREE:\r
 761                 if (SCSI_ReadFilt(SCSI_Filt_BSY))\r
 762                 {\r
 763                         scsiDev.phase = BUS_BUSY;\r
 764                 }\r
 765                 // The Arbitration phase is optional for SCSI1/SASI hosts if there is only\r
 766                 // one initiator in the chain. Support this by moving\r
 767                 // straight to selection if SEL is asserted.\r
 768                 // ie. the initiator won't assert BSY and it's own ID before moving to selection.\r
 769                 else if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
 770                 {\r
 771                         enter_SelectionPhase();\r
 772                 }\r
 773         break;\r
 774 \r
 775         case BUS_BUSY:\r
 776                 // Someone is using the bus. Perhaps they are trying to\r
 777                 // select us.\r
 778                 if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
 779                 {\r
 780                         enter_SelectionPhase();\r
 781                 }\r
 782                 else if (!SCSI_ReadFilt(SCSI_Filt_BSY))\r
 783                 {\r
 784                         scsiDev.phase = BUS_FREE;\r
 785                 }\r
 786         break;\r
 787 \r
 788         case ARBITRATION:\r
 789                 // TODO Support reselection.\r
 790                 break;\r
 791 \r
 792         case SELECTION:\r
 793                 process_SelectionPhase();\r
 794         break;\r
 795 \r
 796         case RESELECTION:\r
 797                 // Not currently supported!\r
 798         break;\r
 799 \r
 800         case COMMAND:\r
 801                 // Do not check ATN here. SCSI 1 & 2 initiators must set ATN\r
 802                 // and SEL together upon entering the selection phase if they\r
 803                 // want to send a message (IDENTIFY) immediately.\r
 804                 if (scsiDev.atnFlag)\r
 805                 {\r
 806                         process_MessageOut();\r
 807                 }\r
 808                 else\r
 809                 {\r
 810                         process_Command();\r
 811                 }\r
 812         break;\r
 813 \r
 814         case DATA_IN:\r
 815                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 816                 if (scsiDev.atnFlag)\r
 817                 {\r
 818                         process_MessageOut();\r
 819                 }\r
 820                 else\r
 821                 {\r
 822                         process_DataIn();\r
 823                 }\r
 824         break;\r
 825 \r
 826         case DATA_OUT:\r
 827                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 828                 if (scsiDev.atnFlag)\r
 829                 {\r
 830                         process_MessageOut();\r
 831                 }\r
 832                 else\r
 833                 {\r
 834                         process_DataOut();\r
 835                 }\r
 836         break;\r
 837 \r
 838         case STATUS:\r
 839                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 840                 if (scsiDev.atnFlag)\r
 841                 {\r
 842                         process_MessageOut();\r
 843                 }\r
 844                 else\r
 845                 {\r
 846                         process_Status();\r
 847                 }\r
 848         break;\r
 849 \r
 850         case MESSAGE_IN:\r
 851                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 852                 if (scsiDev.atnFlag)\r
 853                 {\r
 854                         process_MessageOut();\r
 855                 }\r
 856                 else\r
 857                 {\r
 858                         process_MessageIn();\r
 859                 }\r
 860 \r
 861         break;\r
 862 \r
 863         case MESSAGE_OUT:\r
 864                 process_MessageOut();\r
 865         break;\r
 866         }\r
 867 }\r
 868 \r
 869 void scsiInit()\r
 870 {\r
 871         scsiDev.atnFlag = 0;\r
 872         scsiDev.resetFlag = 1;\r
 873         scsiDev.phase = BUS_FREE;\r
 874         scsiDev.target = NULL;\r
 875 \r
 876         int i;\r
 877         for (i = 0; i < MAX_SCSI_TARGETS; ++i)\r
 878         {\r
 879                 const TargetConfig* cfg = getConfigByIndex(i);\r
 880                 if (cfg && (cfg->scsiId & CONFIG_TARGET_ENABLED))\r
 881                 {\r
 882                         scsiDev.targets[i].targetId = cfg->scsiId & CONFIG_TARGET_ID_BITS;\r
 883                         scsiDev.targets[i].cfg = cfg;\r
 884 \r
 885                         scsiDev.targets[i].liveCfg.bytesPerSector = cfg->bytesPerSector;\r
 886                 }\r
 887                 else\r
 888                 {\r
 889                         scsiDev.targets[i].targetId = 0xff;\r
 890                         scsiDev.targets[i].cfg = NULL;\r
 891                 }\r
 892                 scsiDev.targets[i].reservedId = -1;\r
 893                 scsiDev.targets[i].reserverId = -1;\r
 894                 scsiDev.targets[i].unitAttention = POWER_ON_RESET;\r
 895                 scsiDev.targets[i].sense.code = NO_SENSE;\r
 896                 scsiDev.targets[i].sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 897         }\r
 898 }\r
 899 \r
 900 void scsiDisconnect()\r
 901 {\r
 902         scsiEnterPhase(MESSAGE_IN);\r
 903         scsiWriteByte(0x02); // save data pointer\r
 904         scsiWriteByte(0x04); // disconnect msg.\r
 905 \r
 906         // For now, the caller is responsible for tracking the disconnected\r
 907         // state, and calling scsiReconnect.\r
 908         // Ideally the client would exit their loop and we'd implement this\r
 909         // as part of scsiPoll\r
 910         int phase = scsiDev.phase;\r
 911         enter_BusFree();\r
 912         scsiDev.phase = phase;\r
 913 }\r
 914 \r
 915 int scsiReconnect()\r
 916 {\r
 917         int reconnected = 0;\r
 918 \r
 919         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 920         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 921         if (!sel && !bsy)\r
 922         {\r
 923                 CyDelayUs(1);\r
 924                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 925                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 926         }\r
 927 \r
 928         if (!sel && !bsy)\r
 929         {\r
 930                 // Arbitrate.\r
 931                 ledOn();\r
 932                 uint8_t scsiIdMask = 1 << scsiDev.target->targetId;\r
 933                 SCSI_Out_Bits_Write(scsiIdMask);\r
 934                 SCSI_Out_Ctl_Write(1); // Write bits manually.\r
 935                 SCSI_SetPin(SCSI_Out_BSY);\r
 936 \r
 937                 CyDelayUs(3); // arbitrate delay. 2.4us.\r
 938 \r
 939                 uint8_t dbx = scsiReadDBxPins();\r
 940                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 941                 if (sel || ((dbx ^ scsiIdMask) > scsiIdMask))\r
 942                 {\r
 943                         // Lost arbitration.\r
 944                         SCSI_Out_Ctl_Write(0);\r
 945                         SCSI_ClearPin(SCSI_Out_BSY);\r
 946                         ledOff();\r
 947                 }\r
 948                 else\r
 949                 {\r
 950                         // Won arbitration\r
 951                         SCSI_SetPin(SCSI_Out_SEL);\r
 952                         CyDelayUs(1); // Bus clear + Bus settle.\r
 953 \r
 954                         // Reselection phase\r
 955                         SCSI_CTL_PHASE_Write(__scsiphase_io);\r
 956                         SCSI_Out_Bits_Write(scsiIdMask | (1 << scsiDev.initiatorId));\r
 957                         scsiDeskewDelay(); // 2 deskew delays\r
 958                         scsiDeskewDelay(); // 2 deskew delays\r
 959                         SCSI_ClearPin(SCSI_Out_BSY);\r
 960                         CyDelayUs(1);  // Bus Settle Delay\r
 961 \r
 962                         uint32_t waitStart_ms = getTime_ms();\r
 963                         bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 964                         // Wait for initiator.\r
 965                         while (\r
 966                                 !bsy &&\r
 967                                 !scsiDev.resetFlag &&\r
 968                                 (elapsedTime_ms(waitStart_ms) < 250))\r
 969                         {\r
 970                                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 971                         }\r
 972 \r
 973                         if (bsy)\r
 974                         {\r
 975                                 SCSI_SetPin(SCSI_Out_BSY);\r
 976                                 scsiDeskewDelay(); // 2 deskew delays\r
 977                                 scsiDeskewDelay(); // 2 deskew delays\r
 978                                 SCSI_ClearPin(SCSI_Out_SEL);\r
 979 \r
 980                                 // Prepare for the initial IDENTIFY message.\r
 981                                 SCSI_Out_Ctl_Write(0);\r
 982                                 scsiEnterPhase(MESSAGE_IN);\r
 983 \r
 984                                 // Send identify command\r
 985                                 scsiWriteByte(0x80);\r
 986 \r
 987                                 scsiEnterPhase(scsiDev.phase);\r
 988                                 reconnected = 1;\r
 989                         }\r
 990                         else\r
 991                         {\r
 992                                 // reselect timeout.\r
 993                                 SCSI_Out_Ctl_Write(0);\r
 994                                 SCSI_ClearPin(SCSI_Out_SEL);\r
 995                                 SCSI_CTL_PHASE_Write(0);\r
 996                                 ledOff();\r
 997                         }\r
 998                 }\r
 999         }\r
1000         return reconnected;\r
1001 }\r
1002 \r
1003 #pragma GCC pop_options\r