iokit/Drivers/scsi/drvSymbios8xx/Sym8xxScript.ss

   1
   2 ; Copyright (c) 1997-1999 Apple Computer, Inc. All rights reserved.
   3 ;
   4 ; @APPLE_LICENSE_HEADER_START@
   5 ;
   6 ; The contents of this file constitute Original Code as defined in and
   7 ; are subject to the Apple Public Source License Version 1.1 (the
   8 ; "License").  You may not use this file except in compliance with the
   9 ; License.  Please obtain a copy of the License at
  10 ; http://www.apple.com/publicsource and read it before using this file.
  11 ;
  12 ; This Original Code and all software distributed under the License are
  13 ; distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14 ; EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15 ; INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16 ; FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17 ; License for the specific language governing rights and limitations
  18 ; under the License.
  19 ;
  20 ; @APPLE_LICENSE_HEADER_END@
  21 ;
  22 ;   File Ownership:
  23 ;
  24 ;       DRI:            Mike Johnson
  25 ;
  26 ;       Other Contact:  Russ Berkoff
  27 ;
  28 ;       Technology:     SCSI
  29 ;
  30 ;   Writers:
  31 ;
  32 ;       (MLJ)   Mike Johnson
  33 ;       (RRA)   Rick Auricchio
  34
  35
  36 ;       NCR Errata Listing 125 Item 1 : Clear the SCNTL0 start bit
  37 ;       when jump to reselect during select (try_reselect)
  38 ;
  39 ;       NCR Errata Listing 117 Item 4 : Bad parity if odd bytes during
  40 ;       wide transfer. Only for DATA OUT in Initiator mode.
  41 ;       (Confirm by Manfred Eierle 3rd June 93 not during DATA IN)
  42
  43     ARCH     825A                ;specifically for 825a and 875 (new instructions)
  44
  45
  46         ;*****************************************************************
  47         ;
  48         ;   Phase codes - These values represent which action is being handled
  49         ;
  50         ;*****************************************************************
  51
  52     ABSOLUTE kphase_DATA_OUT                = 0x00
  53     ABSOLUTE kphase_DATA_IN                 = 0x01
  54     ABSOLUTE kphase_COMMAND                 = 0x02
  55     ABSOLUTE kphase_STATUS                  = 0x03
  56     ABSOLUTE kphase_MSG_OUT                 = 0x06
  57     ABSOLUTE kphase_MSG_IN                  = 0x07
  58     ABSOLUTE kphase_SELECT                  = 0x08
  59     ABSOLUTE kphase_RESELECT                = 0x09
  60     ABSOLUTE kphase_ABORT_CURRENT           = 0x0A
  61     ABSOLUTE kphase_ABORT_MAILBOX           = 0x0B
  62     ABSOLUTE kphase_CMD_COMPLETE            = 0x0C
  63     ABSOLUTE kphase_DISCONNECT              = 0x0D
  64     ABSOLUTE kphase_saveDataPointer         = 0x0E  ; ??? driver work to be done
  65     ABSOLUTE kphase_restoreDataPointer      = 0x0F  ; ??? driver work to be done
  66
  67
  68         ;*****************************************************************
  69         ;   interrupt codes
  70         ;*****************************************************************
  71
  72     ABSOLUTE unknown_phase              = 0x00  ; A spurious phase on SCSI Bus
  73     ABSOLUTE status_error               = 0x01  ; IO completes, but with status error
  74     ABSOLUTE unexpected_msg             = 0x02  ; An 'unknown' message is in ld_message var
  75     ABSOLUTE unexpected_ext_msg         = 0x03  ; An 'unknown' extended message in ld_message
  76     ABSOLUTE wide_32_not_supported      = 0x04  ; The device wants 32 bits data phase
  77     ABSOLUTE no_msgin_after_reselect    = 0x05  ; No message-in after reselection
  78     ABSOLUTE reqack_too_large           = 0x06  ; The device answer ReqAck offset is greater than 8
  79     ABSOLUTE unknown_reselect           = 0x07  ; The valid bit in SFBR reg not set
  80     ABSOLUTE unallocated_nexus          = 0x08  ; nexus index -> 0xFFFFFFFF
  81     ABSOLUTE abort_mailbox              = 0x09  ; Abort/BDR mailbox completed
  82     ABSOLUTE abort_current              = 0x0A  ; Abort/BDR current op completed
  83     ABSOLUTE unknown_message_out        = 0x0B  ; Unknown phase before message out
  84     ABSOLUTE unknown_msg_reject         = 0x0C  ; Unknown message reject
  85     ABSOLUTE negotiateSDTR              = 0x0D  ; Sync negotiation rx'd
  86     ABSOLUTE negotiateWDTR              = 0x0E  ; Wide negotiation rx'd
  87     ABSOLUTE sglist_complete            = 0x0F  ; SGList complete
  88
  89
  90         ;*****************************************************************
  91         ;
  92         ; Data structure for T/L/Q Nexus:
  93         ;
  94         ;*****************************************************************
  95
  96     ABSOLUTE TLQ_SCSI_ID    =  0    ;  4 SCSI ID et al for SELECT instruction
  97     ABSOLUTE TLQ_xferAdr    =  4    ;  4 Physical address of CHMOV instructions
  98     ABSOLUTE TLQ_MSGOp      =  8    ;  8 Byte count, data adr   -> TLQ_MSGO
  99     ABSOLUTE TLQ_CDBp       = 16    ;  8 Byte count, data adr   -> TLQ_CDB
 100     ABSOLUTE TLQ_CDP        = 24    ;  4 Current Data Pointer
 101     ABSOLUTE TLQ_SDP        = 28    ;  4 Saved   Data Pointer
 102     ABSOLUTE TLQ_index      = 32    ;  1 index into nexus array
 103     ABSOLUTE TLQ_xferStarted= 33    ;  1 transfer started flag
 104     ABSOLUTE TLQ_IWR        = 34    ;  1 flag to Ignore Wide Residue
 105     ABSOLUTE TLQ_pad        = 35    ;  1 pad byte
 106
 107
 108         ;*****************************************************************
 109         ;
 110         ; ENTRY declarations - Declare entry points for driver
 111         ;
 112         ;*****************************************************************
 113
 114     ENTRY   select_phase
 115     ENTRY   phase_handler
 116     ENTRY   issueMessageOut         ; for negotiation and Reject messages
 117     ENTRY   issueAbort_BDR          ; to immediately Abort or Bus-Device-Reset
 118     ENTRY   clearACK                ; MsgIn done - clr ACK, jump to phase handler
 119
 120
 121         ;*****************************************************************
 122         ;
 123         ; Define local data structure at start of SCRIPTS.
 124         ; This structure is allocated by the following nops.
 125         ;
 126         ;*****************************************************************
 127         ;
 128
 129     RELATIVE local_data     \
 130         ld_AbortCode                = 4{??}\    ; 1 byte code to Abort or BDR
 131         ld_zeroes                   = 4{??}\    ; 4 bytes of 0 to clear registers
 132         ld_status                   = 4{??}\    ; Status byte from target
 133         ld_counter                  = 4{??}\    ; index into mailbox array
 134            ld_AbortBdr_mailbox      = 4{??}\    ; Abort/BusDeviceReset mailbox
 135            ld_IOdone_mailbox        = 4{??}\    ; [ nexus 0 0 semaphore ]
 136            ld_sched_mlbx_base_adr   = 4{??}\    ; base addr of mailbox array
 137            ld_mailboxp              = 4{??}\    ; address of current mailbox
 138         ld_scsi_id                  = 4{??}\    ; ptr to current mailbox
 139         ld_nexus_array_base         = 4{??}\    ; base address of Nexus pointers
 140         ld_nexus_index              = 4{??}\    ; index to Nexus pointer
 141         ld_nexus                    = 4{??}\    ; address of Nexus
 142            ld_phase_flag            = 4{??}\    ; for debugging
 143            ld_device_table_base_adr = 4{??}\    ; device configuration table
 144            ld_scratch               = 4{??}\    ; scratch memory
 145            ld_unused                = 4{??}\    ; unused
 146         ld_message                  = 4{??}\    ; buffer for MsgIn bytes
 147         ld_message4                 = 4{??}\    ; buffer continuation
 148         ld_pad                      = 4{??}\    ; padding
 149         ld_size                     = 4{??}     ; size of this structure
 150
 151
 152 PROC BSC_SCRIPT:
 153
 154         ; *** These NOPs must be at address 0.                          ***
 155         ; *** This is reserved space for the structure "local_data".    ***
 156         ; *** The driver inits this area to zero.                       ***
 157
 158     nop 0       ; ld_AbortCode,             ld_zeroes
 159     nop 0       ; ld_status,                ld_counter
 160
 161     nop 0       ; ld_AbortBdr_mailbox,      ld_IOdone_mailbox
 162     nop 0       ; ld_sched_mlbx_base_adr,   ld_mailboxp
 163
 164     nop 0       ; ld_scsi_id,               ld_nexus_array_base
 165     nop 0       ; ld_nexus_index,           ld_nexus
 166
 167     nop 0       ; ld_phase_flag,            ld_device_table_base_adr
 168     nop 0       ; ld_scratch,               ld_unused
 169
 170     nop 0       ; ld_message,               ld_message4
 171     nop ld_size ; ld_pad,                   ld_size     (Use ld_size or lose it)
 172
 173     nop sglist_complete     ; use sglist_complete or lose it from gen'd output file
 174
 175     ;****************************************************************************
 176     ;
 177     ; findNexusFromIndex - load DSA with pointer to Nexus given a Nexus index:
 178     ;
 179     ;****************************************************************************
 180
 181 findNexusFromIndex:
 182
 183     load SCRATCHA0, 4, ld_nexus_index       ; load index and leading zeroes
 184     clear CARRY
 185     move SCRATCHA0 SHL 0 to SCRATCHA0       ; double the index
 186     move SCRATCHA1 SHL 0 to SCRATCHA1
 187     move SCRATCHA0 SHL 0 to SCRATCHA0       ; double again
 188     move SCRATCHA1 SHL 0 to SCRATCHA1       ; A0 now has index to 4-byte address
 189     store SCRATCHA0, 4, patchArrayOffset+4  ; *** patch the code
 190
 191     load DSA0, 4, ld_nexus_array_base       ; load base address of array of Nexus pointers
 192 patchArrayOffset:
 193     load DSA0, 4, DSAREL( 0 )               ; *** patched offset. Load pointer.
 194
 195     move DSA0 to SFBR                       ; Ensure pointer is not 0xFFFFFFFF
 196     int unallocated_nexus, if 0xFF          ; Interrupt if NFG
 197
 198     store DSA0, 4, ld_nexus                 ; Store the Nexus pointer
 199     return                                  ; end findNexusFromIndex
 200
 201
 202     ;****************************************************************************
 203     ;
 204     ; initContext - Initialize the registers for Sync and Wide using
 205     ;   values stored in the device configuration table.
 206     ;   Return with values in SCRATCHB for Select code.
 207     ;
 208     ;****************************************************************************
 209
 210 initContext:
 211
 212     load SCRATCHB0, 4, ld_scsi_id                   ; load 4-bit SCSI ID and zeroes
 213     clear CARRY
 214     move SCRATCHB0 SHL SCRATCHB0                    ; * 2
 215     move SCRATCHB0 SHL SCRATCHB0                    ; * 2 -> UInt32 index
 216     store SCRATCHB0, 4, patchGetDevConfigOffset+4   ; *** Patch load  code
 217
 218     load DSA0, 4, ld_device_table_base_adr          ; load base physical addr of tables
 219
 220 patchGetDevConfigOffset:
 221     load  SCRATCHB0, 4, DSAREL( 0 )                 ; *** Patched table offset ***
 222
 223         ; SCRATCHB0 = 0
 224         ; SCRATCHB1 = TP,MO (SXFER bits7-5 bits3-0)
 225         ; SCRATCHB2 = 0 (position for SCSI ID)
 226         ; SCRATCHB3 = SCCF,EWS (SCNTL3 bits6-4 bit 3)
 227
 228     move SCRATCHB1 to SFBR                          ; init SXFER from B1
 229     move SFBR to SXFER
 230                                                     ; Init SCNTL3 from B3
 231     move SCRATCHB3 to SFBR
 232     move SFBR to SCNTL3
 233     return                                          ; return with SCRATCHB intact.
 234
 235
 236     ;*****************************************************************
 237     ;
 238     ; Select_phase:
 239     ;       Clear the SIGP bit.
 240     ;       Check if any Abort/BusDeviceReset request waiting.
 241     ;       Nexus is found in the list of 256 mailboxes.
 242     ;       If current mailbox is empty, jump to reselect_phase.
 243     ;       SCRIPTS tries to select device.
 244     ;       If select fails due to reselect, jump to reselect_phase
 245     ;       Select Timeout handled by driver.
 246     ;       If select succeeds, clear the mailbox entry
 247     ;       and increment the mailbox counter.
 248     ;       Jump to the phase_handler (hopefully for MSG_OUT)
 249     ;
 250     ;*****************************************************************
 251
 252 select_phase:
 253
 254     move CTEST2 | 0x00 to CTEST2           ; Clear SIGP bit from ISTAT reg
 255
 256         ; Check abort mailbox:
 257
 258     load SCRATCHA0, 4, ld_AbortBdr_mailbox ; Get AbortBdr mailbox
 259         ; The Identify byte in byte 0 is also the semaphore
 260         ; A0 = Identify byte (0xC0 + LUN  N.B. Disconnect allowed)
 261         ; A1 = Tag, if any
 262         ; A2 = SCSI ID
 263         ; A3 = Abort code   Abort=0x06; Abort Tag=0D; Bus Device Reset=0x0C
 264     move SCRATCHA0 to SFBR                  ; test the semaphore/Identify
 265     jump rel( AbortMailbox ), if not 0      ; jump if aborting
 266
 267
 268         ; Get the next IO nexus in the mailboxes circular list.
 269         ; Calculate current mailbox address as so:
 270         ;   counter byte index * 4  to get mailbox index
 271         ;   add base physical address of mailboxes giving current mailbox address
 272
 273     load SCRATCHA0, 4, ld_counter           ; get 1-byte mailbox counter & 0s
 274     clear CARRY
 275     move SCRATCHA0 SHL 0 to SCRATCHA0       ; double it
 276     move SCRATCHA1 SHL 0 to SCRATCHA1
 277     move SCRATCHA0 SHL 0 to SCRATCHA0       ; double it again
 278     move SCRATCHA1 SHL 0 to SCRATCHA1       ; now have a UInt32 index
 279     store SCRATCHA0, 4, fetchMailbox+4      ; *** patch the load  DSA instruction
 280     store SCRATCHA0, 4, clear_mailbox+4     ; *** patch the store DSA instruction
 281
 282     load DSA0, 4, ld_sched_mlbx_base_adr    ; load base physical address of mailboxes
 283
 284 fetchMailbox:
 285     load  DSA0, 4, DSAREL( 0 )              ; *** Patched offset. Load Nexus address
 286     store DSA0, 4, ld_nexus                 ; save pointer to current Nexus
 287     load SCRATCHA0, 4, ld_nexus             ; copy to A0
 288
 289     move SCRATCHA0 to SFBR                  ;
 290     jump rel( next_mailbox ), if 1          ; if low-byte == 0x01 then cancelled mailbox
 291
 292     move SCRATCHA1 | SFBR to SFBR           ; if non-zero, have implicit semaphore
 293     move SCRATCHA2 | SFBR to SFBR
 294     move SCRATCHA3 | SFBR to SFBR
 295     jump rel( reselect_phase ), if 0        ; go to reselect_phase if empty
 296
 297         ;*****************************************************************
 298         ;
 299         ; Something in mailbox: we have work to do
 300         ;
 301         ;*****************************************************************
 302
 303     move kphase_SELECT to SCRATCHB0             ; set phase indicator
 304     store SCRATCHB0, 1, ld_phase_flag
 305
 306     load  SCRATCHB0, 4, ld_zeroes               ; clr the invalid-nexus-index flag
 307     load  SCRATCHB0, 1, DSAREL( TLQ_index )     ; get index byte from nexus
 308     store SCRATCHB0, 4, ld_nexus_index          ; save it in local data
 309
 310     load DSA0, 4, ld_nexus                      ; restore DSA register
 311     load SCRATCHB2, 1, DSAREL( TLQ_SCSI_ID+2 )  ; get Target's SCSI ID
 312     move SCRATCHB2 to SFBR
 313     move SFBR to SCRATCHB0                      ; position it
 314     store SCRATCHB0, 1, ld_scsi_id              ; save it
 315     call rel( initContext )                     ; setup Sync/Wide regs in SCRATCHB
 316     load DSA0, 4, ld_nexus                      ; restore DSA register
 317     store SCRATCHB1, 1, DSAREL( TLQ_SCSI_ID+1 ) ; SXFER
 318     store SCRATCHB3, 1, DSAREL( TLQ_SCSI_ID+3 ) ; SCNTL3
 319
 320         ;********************** select the device ********************************
 321     SELECT ATN from TLQ_SCSI_ID, rel( try_reselect )    ; ************************
 322         ;*************************************************************************
 323
 324         ; looking good - clear the mailbox:
 325
 326 next_mailbox:
 327     load SCRATCHA0, 4, ld_zeroes            ; zero out scratch register A
 328     load DSA0, 4, ld_sched_mlbx_base_adr    ; load base physical address of mailboxes
 329 clear_mailbox:
 330     store SCRATCHA0, 4, DSAREL( 0 )         ; *** Patched offset. Zero the mailbox
 331
 332         ; Update the index to the mailbox circular list:
 333     load SCRATCHB0, 1, ld_counter           ; get counter (mailbox index)
 334     move SCRATCHB0 + 1 to SCRATCHB0         ; add 1
 335     store SCRATCHB0, 1, ld_counter  ; put it back
 336
 337     load SCRATCHB0, 1, ld_nexus             ; if low-byte == 0x01 then cancelled mailbox
 338     move SCRATCHB0 to SFBR
 339     jump rel( select_phase ), if 1
 340
 341 ;   *** FALL THROUGH TO phase_handler ***
 342
 343
 344     ;*****************************************************************
 345     ;
 346     ;   Phase_handler
 347     ;       The phase handler script is a dispatcher function of SCSI phase
 348     ;
 349     ;*****************************************************************
 350
 351 phase_handler:
 352     load DSA0, 4, ld_nexus                          ; reload DSA
 353     jump rel( command_phase ),        when CMD      ; wait for REQ
 354     jump rel( data_out_phase ),       if DATA_OUT   ; already latched REQ signal
 355     jump rel( message_out_phase ),    if MSG_OUT
 356     jump rel( data_in_phase ),        if DATA_IN
 357     jump rel( status_phase ),         if STATUS
 358     jump rel( message_in_phase ),     if MSG_IN
 359     int     unknown_phase
 360
 361
 362     ;*****************************************************************
 363     ;
 364     ; Message-Out phase
 365     ;
 366     ;*****************************************************************
 367
 368 message_out_phase:
 369     move kphase_MSG_OUT to SCRATCHB0                ; Set phase indicator
 370     store SCRATCHB0, 1, ld_phase_flag
 371
 372     move from TLQ_MSGOp, when MSG_OUT               ; put out the message(s)
 373     jump rel( phase_handler )
 374
 375
 376         ; issueMessageOut - Driver entry point for Sync/Wide negotiation and
 377         ; to issue message Reject:
 378
 379 issueMessageOut:
 380     set     ATN                                     ; tell Target we have something to say
 381     clear   ACK
 382     jump rel( message_out_phase ),  when MSG_OUT    ; wait for REQ. Jump if msg-out phase.
 383     jump rel( phase_handler ),      if not MSG_IN   ; jump if weird phase
 384     move 1, ld_scratch+1,           when   MSG_IN   ; dump the msg byte
 385     clear ACK                                       ; accept Target's last msg-in byte
 386     jump rel( issueMessageOut )
 387
 388
 389     ;*****************************************************************
 390     ;
 391     ;   Command phase
 392     ;
 393     ;*****************************************************************
 394
 395 command_phase:
 396     move kphase_COMMAND to SCRATCHB0    ; Set phase indicator
 397     store SCRATCHB0, 1, ld_phase_flag
 398
 399     clear ATN                           ; In case we missed the sending nego
 400     move FROM TLQ_CDBp, when CMD        ; issue the CDB
 401     jump rel( phase_handler )
 402
 403
 404     ;*****************************************************************
 405     ;
 406     ; Data_out_phase
 407     ;
 408     ;*****************************************************************
 409
 410 data_out_phase:
 411     move kphase_DATA_OUT to SCRATCHB0       ; Set phase indicator
 412     store SCRATCHB0, 1, ld_phase_flag
 413
 414     call rel( driverXfer )                  ; call driver-built CHMOV instructions
 415     jump rel( phase_handler )               ; if all data xfer'd, get next phase
 416
 417 driverXfer:                                 ; get here from data-in code also
 418     load  SCRATCHA0, 4, DSAREL( TLQ_xferAdr )
 419     store SCRATCHA0, 4, doItPatch+4         ; *** patch the JUMP address
 420     move 0xFF to SCRATCHA1
 421     store SCRATCHA1, 1, DSAREL( TLQ_xferStarted )
 422
 423 doItPatch:
 424     jump 0x0333                             ; *** patched address
 425
 426
 427
 428     ;*****************************************************************
 429     ;
 430     ; Data_in_phase
 431     ;   875 sets ATN if bad parity detected.
 432     ;   Use of CHMOV instructions assures that we properly handle
 433     ;   a leftover wide byte in the SWIDE or SODL register, depending
 434     ;   on the data direction. This can happen in either of two conditions:
 435     ;     1. The Target disconnects at an odd boundary. This is
 436     ;       extremely unlikely with disk devices.
 437     ;     2. The client passes either an odd buffer address or
 438     ;       an odd transfer count. When the Target disconnects (at
 439     ;       an even boundary, we end up with the extra wide
 440     ;       byte in SWIDE or SODL. MacOS does this with VM on.
 441     ;
 442     ;*****************************************************************
 443
 444 data_in_phase:
 445     move kphase_DATA_IN to SCRATCHB0        ; Set phase indicator
 446     store SCRATCHB0, 1, ld_phase_flag
 447
 448     call rel( driverXfer )                  ; call driver-built CHMOV instructions
 449
 450     ; The driver gets interrupted if a phase mismatch occurs as when
 451     ; the Target goes MSG-IN with a Disconnect.
 452     ; The driver codes either a RETURN if the Scatter/Gather list is complete or
 453     ; an INT if more Scatter/Gather elements need to be generated.
 454     ; On the Macintosh, client programs expect extra incoming data to be dumped.
 455     ; For example, during boot the ROM reads 512 bytes from a 2K-byte-sector CD.
 456
 457 bucket_loop:
 458     jump rel( phase_handler ), when not DATA_IN ; wait for phase, exit if changed
 459     CHMOV 1, ld_status, when DATA_IN            ; eat a byte
 460     jump rel( bucket_loop );                    ; keep dumping bytes
 461
 462
 463     ;*****************************************************************
 464     ;
 465     ; Status phase
 466     ;
 467     ;*****************************************************************
 468
 469 status_phase:
 470     move kphase_STATUS to SCRATCHB0             ; Set phase indicator
 471     store SCRATCHB0, 1, ld_phase_flag
 472
 473     move 1, ld_status, when STATUS              ; Read Status byte from bus
 474     jump rel( phase_handler )
 475
 476
 477     ;*****************************************************************
 478     ;
 479     ; Message-In phase
 480     ;
 481     ;*****************************************************************
 482
 483 message_in_phase:
 484     move kphase_MSG_IN to SCRATCHB0             ; Set phase indicator
 485     store SCRATCHB0, 1, ld_phase_flag
 486
 487     move 1, ld_message, when MSG_IN             ; Read byte from bus
 488
 489     jump rel( cmdComplete ),        if 0x00     ; Command Complete
 490     jump rel( saveDataPointer ),    if 0x02     ; Save Data Pointer
 491     jump rel( disconnect_msg ),     if 0x04     ; Disconnect
 492     jump rel( ignoreWideResidue ),  if 0x23     ; Ignore Wide Residue
 493     jump rel( restoreDataPointer ), if 0x03     ; Restore Data Pointer
 494     jump rel( extended_msg ),       if 0x01     ; Extended message
 495     jump rel( msg_reject ),         if 0x07     ; Message Reject
 496         ; Identify,                 if 0x80-FF  ; Identify + LUN
 497         ; simple_queue_tag,         if 0x20     ; Simple Queue Tag
 498         ; initiate_recovery,        if 0x0F     ; Initiate Recovery
 499         ; linked_cde_complete,      if 0x0A/0x0B
 500     int unexpected_msg                          ; unknown
 501
 502 msg_reject:
 503     int  unknown_msg_reject
 504
 505 clearACK:                                       ; ENTRY point to end negotiation
 506     clear ACK
 507     jump rel( phase_handler )
 508
 509
 510
 511     ;*****************************************************************
 512     ;
 513     ; Ignore Wide Residue
 514     ;
 515     ;*****************************************************************
 516
 517 ignoreWideResidue:      ; this is a two byte message so snag the 2nd byte here
 518     clear ACK
 519     move 1, ld_message+1, when MSG_IN       ; save residue count
 520     move SFBR to SCRATCHB2                  ; byte is still in SFBR. Position it.
 521     store SCRATCHB2, 1, DSAREL( TLQ_IWR )   ; Store residue count in Nexus for driver.
 522     clear ACK
 523     jump rel( phase_handler )
 524
 525
 526     ;*****************************************************************
 527     ;
 528     ; Extended message
 529     ;       Accept Wide and Synchronous Data Transfer messages
 530     ;
 531     ;*****************************************************************
 532
 533 extended_msg:
 534     clear ACK
 535     move 1, ld_message+1, when MSG_IN       ; read msg length byte from bus
 536     clear ACK
 537     move 1, ld_message+2, when MSG_IN       ; read ext msg code from bus
 538     clear ACK
 539         ; extended_identify,   IF 0x02
 540         ; modify_data_pointer, if 0x00
 541     jump rel( sdtr ),   if 0x01             ; jump if SDTR, sync negotiation msg
 542     jump rel( wdtr ),   if 0x03             ; jump if WDTR, wide negotiation msg
 543     int unexpected_ext_msg                  ; let driver deal with unknown
 544
 545
 546     ;*****************************************************************
 547     ;
 548     ; Command complete
 549     ;       The Command-Complete message is sent to indicate that the
 550     ;       IO operation has completed and valid status has been sent.
 551     ;       The Target should then disconnect.
 552     ;       SCRIPTS must spin until the IOdone mailbox is empty.
 553     ;       Then it sets the IOdone mailbox with the current Nexus.
 554     ;       The status message is analyzed.
 555     ;       If status is good, INTF the driver and jump to select_phase.
 556     ;       If status is NG, save it in the NEXUS and INT the driver.
 557     ;
 558     ;*****************************************************************
 559
 560 cmdComplete:
 561     move kphase_CMD_COMPLETE to SCRATCHB0       ; Set phase indicator
 562     store SCRATCHB0, 1, ld_phase_flag
 563
 564     move SCNTL2 & 0X7F to SCNTL2                ; Clr SDU: SCSI Disconnect Unexpected
 565     clear ACK
 566     WAIT DISCONNECT
 567
 568 testMbxLp:                                      ; loop until IOdone mailbox empty
 569     load SCRATCHA0, 4, ld_IOdone_mailbox
 570     move SCRATCHA3 to SFBR                      ; A3 = semaphore
 571     jump rel( testMbxLp ), if not 0
 572
 573         ; Fill in the IOdone mailbox with the following:
 574         ;   A0 = index to Nexus
 575         ;   A1 = Status
 576         ;   A2 = 0
 577         ;   A3 = semaphore (FF = set)
 578     load SCRATCHA0, 1, ld_nexus_index       ; A0 = index to Nexus
 579     load SCRATCHB0, 1, ld_status
 580     move SCRATCHB0 to SFBR
 581     move SFBR to SCRATCHA1                  ; A1 = Status
 582     move 0x00 to SCRATCHA2                  ; A2 = 0
 583     move 0xFF to SCRATCHA3                  ; A3 = semaphore IOdone mailbox
 584     store SCRATCHA0, 4, ld_IOdone_mailbox
 585
 586     move SCRATCHA1 to SFBR                  ; Test the Status of this IO
 587         ; SFBR = status msg
 588         ; Test status - If good, Interrupt on the fly and jump to select phase
 589     intfly 0xFF, if 0 and mask 0xC1         ; mask off reserved bits
 590     jump rel( select_phase ), if 0 and mask 0xC1
 591     int     status_error                    ; Status err. Interrupt driver & stop
 592
 593
 594     ;*****************************************************************
 595     ;
 596     ; Disconnect
 597     ;       The 8xx Accepts the disconnection and jumps to the select_phase
 598     ;       to check for another IO
 599     ;
 600     ;*****************************************************************
 601
 602 disconnect_msg:
 603     load SCRATCHB0, 1, ld_phase_flag
 604     move SCRATCHB0 to SFBR
 605         ; If we got here from reselect just bailout since ld_nexus is
 606         ; not setup and the code using it is not needed anyway (no data xfer)
 607     jump rel( bailout ), if kphase_RESELECT
 608
 609     move kphase_DISCONNECT to SCRATCHB0
 610     store SCRATCHB0, 1, ld_phase_flag
 611
 612 bailout:
 613     move 0xFF to SCRATCHB3                  ; invalidate nexus index for driver
 614     store SCRATCHB3, 1, ld_nexus_index+3
 615     move SCNTL2 & 0x7F to SCNTL2            ; Clr SDU: SCSI Disconnect Unexpected
 616     clear ACK
 617     WAIT DISCONNECT                         ; wait for bus-free
 618     jump rel( select_phase )                ; go see if more to do
 619
 620
 621     ;******************************************************************
 622     ;
 623     ; ??? mlj - saveDataPointer and restoreDataPointer are incorrect.
 624     ; ??? They basically do nothing.
 625     ; Save Data Pointer
 626     ;
 627     ;*****************************************************************
 628
 629 saveDataPointer:
 630     move kphase_saveDataPointer to SCRATCHB0
 631     store SCRATCHB0, 1, ld_phase_flag
 632     clear ACK
 633     jump rel( phase_handler )
 634
 635
 636     ;******************************************************************
 637     ;
 638     ; ??? mlj - saveDataPointer and restoreDataPointer are incorrect.
 639     ; ??? They basically do nothing.
 640     ; Restore Data Pointer
 641     ;       The local values still blocks, still bytes and data address
 642     ;       must be loaded from the corresponding NEXUS data set.
 643     ;       This message should followed an IDE (parity error)
 644     ;
 645     ;*****************************************************************
 646
 647 restoreDataPointer:
 648     move kphase_restoreDataPointer to SCRATCHB0
 649     store SCRATCHB0, 1, ld_phase_flag
 650     clear ACK
 651     jump rel( phase_handler )
 652
 653
 654     ;*****************************************************************
 655     ;
 656     ; Synchronous data transfer request or response
 657     ;
 658     ;*****************************************************************
 659 sdtr:
 660     move 2, ld_message+3, when MSG_IN       ; Read period & offset from bus
 661     int negotiateSDTR
 662
 663
 664     ;***************************************************************************
 665     ;
 666     ; Wide Data Transfer request or response
 667     ;
 668     ;***************************************************************************
 669 wdtr:
 670     move 1, ld_message+3, when MSG_IN       ; get Transfer Width Exponent fm bus
 671     int  negotiateWDTR
 672
 673
 674     ;*****************************************************************
 675     ;
 676     ; Reselect phase
 677     ;       The chip waits here either for a Reselection from a Target or
 678     ;       a SIGP from the driver indicating something in the mailbox.
 679     ;       If reselected, the script uses the Nexus value which is either
 680     ;       a Tag or a SCSI ID/LUN combo to lookup the Nexus.
 681     ;       Then init the SXFER and SCNTL3 registers from the device config table.
 682     ;
 683     ;*****************************************************************
 684
 685 try_reselect:                               ; Select failed - probably reselecting
 686                                             ; Cf NCR Errata Listing 117 Item 1:
 687     move SCNTL0 & 0xDF to SCNTL0            ; clr Start bit
 688     move CTEST2 | 0x00 to CTEST2            ; Clear SIGP bit from ISTAT reg
 689
 690 reselect_phase:
 691     move kphase_RESELECT to SCRATCHB0       ; Set phase indicator
 692     store SCRATCHB0, 1, ld_phase_flag
 693
 694     move 0xFF to SCRATCHB3                  ; invalidate nexus index for driver
 695     store SCRATCHB3, 1, ld_nexus_index+3
 696
 697         ; wait here for reselect from a Target
 698         ; or SIGP from the driver
 699
 700     WAIT RESELECT REL( select_phase )       ; jump if SIGP
 701
 702         ; Reselected:
 703
 704     move SSID to SFBR                       ; SSID = [ Valxxx Scsi_id ]
 705     int unknown_reselect, if 0 and mask 0x7F; Interrupt if VAL bit not set
 706     move SFBR & 0x0F to SCRATCHB0           ; B0 = Target ID
 707     store SCRATCHB0, 1, ld_scsi_id          ; save it
 708
 709     call rel( initContext )                 ; setup sync regs here
 710
 711     int no_msgin_after_reselect, when not MSG_IN
 712
 713     move 1, ld_message, when MSG_IN         ; Read Identify byte from bus
 714
 715         ; if another REQ is asserted, a SimpleQueueTag message should be next
 716
 717     clear ACK                               ; notify Target: msg byte rx'd
 718     jump rel( getNextMsg ), when MSG_IN     ; jump if SimpleQueueTag coming
 719
 720         ; untagged operation:
 721
 722     move SFBR & 0x07 to SCRATCHA0           ; isolate LUN from Identify byte
 723
 724     load SCRATCHB0, 1, ld_scsi_id           ; B0 = Target ID
 725     clear CARRY
 726     move SCRATCHB0 SHL SFBR                 ; shift left #1
 727     move SFBR SHL SCRATCHB0                 ; shift left #2
 728     move SCRATCHB0 SHL SFBR                 ; shift left #3
 729     move SCRATCHA0 | SFBR to SCRATCHA0      ; form Nexus index = 0b0TTTTLLL
 730
 731     store SCRATCHA0, 1, ld_nexus_index      ; store as index to Nexus
 732     jump rel( haveNexusIndex )
 733
 734         ; should be tagged operation:
 735
 736 getNextMsg:
 737     move 1, ld_message,  when MSG_IN        ; read message byte from bus
 738     jump rel( disconnect_msg ), if 0x04     ; if Disconnect, oh well.
 739     clear ACK
 740     jump rel( phase_handler ), if not 0x20; Branch if not Queue tag code
 741         ; get the Queue Tag and save as the nexus index
 742     move 1, ld_nexus_index, when MSG_IN     ; Nexus index <- Tag from bus
 743     clear ACK                               ; acknowledge it
 744
 745 haveNexusIndex:
 746     move 0x00 to SCRATCHB3                  ; clear invalid-nexus-index flag
 747     store SCRATCHB3, 1, ld_nexus_index+3
 748     call rel( findNexusFromIndex )          ; set DSA <- Nexus pointer
 749     jump rel( phase_handler )               ; start handling phases.
 750
 751
 752         ;*****************************************************************
 753         ;
 754         ; AbortMailbox - Abort (or BusDeviceReset) the mailbox entry.
 755         ; This is a queued operation - not an immediate
 756         ; operation as is issueAbort_BDR.
 757         ;   The Abort message clears all IO processes for the
 758         ;   selecting Initiator on the specified LUN.
 759         ;
 760         ;   The Bus Device Reset message clears all IO processes for
 761         ;   all Initiators on all LUNs of selected Target.
 762         ;   It forces a hard reset condition to the selected SCSI device.
 763         ;
 764         ;   A0 = Identify byte (0xC0 + LUN  N.B. Disconnect allowed)
 765         ;   A1 = Tag, if any
 766         ;   A2 = SCSI ID
 767         ;   A3 = Abort code Abort=0x06; Abort Tag=0D; Bus Device Reset=0x0C
 768         ;
 769         ;   Mailbox not cleared by SCRIPTS so that driver can find SCSI ID when done
 770         ;   N.B.: Device is Async and Narrow after BDR!!!
 771         ;   Driver must set the device config table values accordingly.
 772         ;*****************************************************************
 773
 774 AbortMailbox:
 775     move kphase_ABORT_MAILBOX to SCRATCHB0      ; Set phase code
 776     store SCRATCHB0, 1, ld_phase_flag
 777
 778     move 0xFF to SCRATCHB3                      ; invalidate nexus index for driver
 779     store SCRATCHB3, 1, ld_nexus_index+3
 780
 781     load  SCRATCHB2, 1, ld_AbortBdr_mailbox+2   ; get SCSI ID
 782     store SCRATCHB2, 1, AbortSelect+2           ; *** Patch the Select/ATN instruction
 783
 784 AbortSelect:
 785     SELECT ATN 0, REL( try_reselect )           ; *** Patched SCSI ID
 786
 787     move SCRATCHA1 to SFBR                      ; check for Tag
 788     jump rel( taggedAbort ) if not 0x00         ; jump if tagged abort
 789
 790         ; untagged Abort or BusDeviceReset:
 791
 792     move SCRATCHA3 to SFBR                      ; position the abort code
 793     move SFBR to SCRATCHA1
 794     store SCRATCHA0, 2, ld_scratch              ; Store Identify and Abort msgs
 795     move 0x00 to SCNTL2                         ; Clr SDU SCSI Disconnect Unexpected
 796     move 2, ld_scratch , when MSG_OUT           ; emit Identify and Abort messages
 797     WAIT DISCONNECT
 798     int abort_mailbox
 799
 800         ; AbortTag:
 801
 802 taggedAbort:
 803     move SCRATCHA1 to SFBR                      ; position the Tag
 804     move SFBR to SCRATCHA2
 805     move 0x20 to SCRATCHA1                      ; gen SimpleQueueTag code
 806     store SCRATCHA0, 4, ld_scratch              ; store Identify, SQT, Tag, AbortTag
 807     move 0x00 to SCNTL2                         ; Clr SDU SCSI Disconnect Unexpected
 808     move 4, ld_scratch, when MSG_OUT            ; emit all 4 bytes
 809     WAIT DISCONNECT
 810     int abort_mailbox
 811
 812
 813         ;*****************************************************************
 814         ;
 815         ; issueAbort_BDR - Abort (or BusDeviceReset) the current operation.
 816         ; This is an immediate operation - not a queued operation
 817         ; as is AbortMailbox.
 818         ;   The Abort message clears all IO processes for the
 819         ;   selecting Initiator on the specified LUN.
 820         ;
 821         ;   The Bus Device Reset message clears all IO processes for
 822         ;   all Initiators on all LUNs of selected Target.
 823         ;   It forces a hard reset condition to the selected SCSI device.
 824         ;
 825         ;*****************************************************************
 826
 827 issueAbort_BDR:
 828     move kphase_ABORT_CURRENT to SCRATCHB0      ; Set phase code
 829     store SCRATCHB0, 1, ld_phase_flag
 830
 831     move ISTAT & 0x08 to SFBR                   ; see if Target connected to bus
 832     int abort_current, if 0                     ; interrupt driver if not connected
 833
 834     SET ATN                                     ; get Target's attention
 835     load DSA0, 4, ld_nexus                      ; load pointer to Nexus
 836
 837 bucketLoop:
 838     clear ACK
 839     jump rel( sendAbortBDR ),   when MSG_OUT    ; wait for REQ. Jump if OK.
 840
 841     jump rel( BucketInStatus ), if STATUS       ; bit bucket in
 842     jump rel( BucketInMsg ),    if MSG_IN       ; bit bucket in
 843     jump rel( BucketInData ),   if DATA_IN      ; bit bucket in
 844
 845     move 0xAD to SCRATCHA0
 846     jump rel( BucketOutData ),  if DATA_OUT     ; bit bucket out
 847     jump rel( BucketOutCmd ),   if CMD          ; bit bucket out
 848     int unknown_phase                           ; back to driver for harsher measures
 849
 850
 851 BucketInStatus:
 852     move 1, ld_scratch, when STATUS             ; eat the Status byte
 853     jump rel( bucketLoop );                     ; keep bit-bucketing bytes
 854
 855 BucketInMsg:
 856     move 1, ld_scratch, when MSG_IN             ; eat a message byte
 857     jump rel( bucketLoop );                     ; keep bit-bucketing bytes
 858
 859 BucketInData:
 860     move 1, ld_scratch, when DATA_IN            ; eat a data byte
 861     jump rel( bucketLoop );                     ; keep bit-bucketing bytes
 862
 863 BucketOutData:
 864     move SCRATCHA0 xor 0x73 to SCRATCHA0        ; gen 0xDEAD ...
 865     store SCRATCHA0, 1, ld_scratch
 866     move 1, ld_scratch, when DATA_OUT           ; pad a byte out
 867     jump rel( bucketLoop );                     ; keep bit-bucketing bytes
 868
 869 BucketOutCmd:
 870     move 0x00 to SCRATCHA0                      ; load Null, TestUnitReady, whatever
 871     store SCRATCHA0, 1, ld_scratch
 872     move 1, ld_scratch, when CMD                ; pad a byte out
 873     jump rel( bucketLoop );                     ; keep bit-bucketing bytes
 874
 875
 876 sendAbortBDR:
 877     move 0x00 to SCNTL2                         ; Clr SDU SCSI Disconnect Unexpected
 878     move  1, ld_AbortCode, when MSG_OUT         ; Send Abort(06) or BDR(0C) message
 879     load  SCRATCHA0, 4, ld_zeroes               ; load 0's
 880     store SCRATCHA0, 4, ld_AbortCode            ; clear the Abort code
 881     WAIT DISCONNECT
 882     int abort_current                           ; went BusFree - tell Driver