Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### BKIBK

Prolog

Control Block Contents
BKIBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### BKIBK Prolog

     NAME       : HCPBKIBK
     DESCRIPTION: Block I/O Block for DIAGNOSE X'250'
     DSECT      : BKIBK
     FUNCTION   : Main control block for the DIAGNOSE X'250'
                  function; all other information can be found
                  from this block.
     LOCATED BY : VDEVBKIA
     CREATED BY : HCPBICIN, during the initialization of the
                  DIAGNOSE X'250' block I/O environment
     DELETED BY : HCPBICRE, during the removal of the
                  DIAGNOSE X'250' block I/O environment
     SERIALIZED : The block I/O block lock, BKILOCK.
     COMMENTS   : Refer to the description of the VDEVBKIA
                  field for information on the serialization
                  for pointing to this block from the
                  appropriate VDEV. There is one BKIBK for
                  each VDEV for which a DIAGNOSE X'250'
                  environment is initialized.

#### BKIBK Control Block Content

#### BKIBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      BKIBK          Block I/O Block for DIAGNOSE
                                            X'250'
    0000    0 Bitstring    1 BKISTAT        Block I/O function status
              .1.. ....      BKIRESET       X'40' A reset operation is
                                            pending. Note: this flag is set
                                            for serviceability - it is not
                                            checked, since BKIRMPD is always
                                            set as well by the time
                                            reset/remove status needs to be
                                            recognized.
    0001    1 Bitstring    1 BKIFLAGS       Device status flags
              .... .1..      BKIRMPD        X'04' A REMOVE request is pending
              .... ...1      BKIDEVRD       X'01' Virtual device is read only
    0002    2 Bitstring    2 *              Reserved for IBM use
    0004    4 Signed       4 BKIOFFCP       CP offset for CMS disk
         BKIDBCCT indicates processes in HCPDBC. It is used to indicate that
         outstanding i/o is being done maybe by the minidisk cache i/o handler
         (HCPFTUAD). Thus BKIDBIRQ and BKIDBCCT BOTH must be 0 to indicate there
         is no outstanding Diag 250 for this device.
    0008    8 Signed       4 BKIDBCCT       Count of processes in HCPDBC
    000C   12 Signed       4 BKIDBIRQ       Chain of outstanding DBIRQs
    0010   16 Signed       4 BKIDBCWK       Chain of outstanding i/o requests
    0014   20 Signed       4 BKIBLKSZ       Block size of user's disk
    0018   24 Signed       4 BKIOFFST       User's requested offset
    001C   28 Signed       2 BKIVDEVN       Virtual device number
    001E   30 Bitstring    2 *              Reserved for future IBM use
    0020   32 Signed       4 BKISTART       User's starting block
    0024   36 Signed       4 BKIEND         User's ending block
    0028   40 Signed       4 BKIVDEVA       Virtual device block address
    002C   44 Signed       4 BKIDINFO       Address of device information
    0030   48 Signed       4 BKISAVBK       Caller's save block
    0034   52 Signed       4 BKIRMVMD       Address of the VMDBK on which
                                            .the RESET or REMOVE was .issued.
    0038   56 Signed       4 *              Reserved for IBM use
    0040   64 Dbl-Word     8 BKILOCK (3)    BKIBK lock
    0058   88 Signed       4 *              Reserved for IBM use
    005C   92 Signed       4 *              Reserved for IBM use
    0060   96 Signed       4 *              Reserved for IBM Use
    0064  100 Signed       4 *              Reserved for IBM use
              0000000D       BKISIZE        (*-BKIBK+7)/8 Length of BKIBK in
                                            DWs

#### BKIBK Storage Layout

    *** BKIBK - Block I/O Block for DIAGNOSE X'250'
    *
    *     +------+------+-------------+---------------------------+
    *   0 |:STAT |:FLAGS|/////////////|         BKIOFFCP          |
    *     +------+------+-------------+---------------------------+
    *   8 |         BKIDBCCT          |         BKIDBIRQ          |
    *     +---------------------------+---------------------------+
    *  10 |         BKIDBCWK          |         BKIBLKSZ          |
    *     +---------------------------+-------------+-------------+
    *  18 |         BKIOFFST          |  BKIVDEVN   |/////////////|
    *     +---------------------------+-------------+-------------+
    *  20 |         BKISTART          |          BKIEND           |
    *     +---------------------------+---------------------------+
    *  28 |         BKIVDEVA          |         BKIDINFO          |
    *     +---------------------------+---------------------------+
    *  30 |         BKISAVBK          |         BKIRMVMD          |
    *     +---------------------------+---------------------------+
    *  38 |///////////////////////////|///////////////////////////|
    *     +---------------------------+---------------------------+
    *  40 |                                                       |
    *     =                       BKILOCK                         =
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  58 |///////////////////////////|///////////////////////////|
    *     +---------------------------+---------------------------+
    *  60 |///////////////////////////|///////////////////////////|
    *     +---------------------------+---------------------------+
    *  68
    *
    *** BKIBK - Block I/O Block for DIAGNOSE X'250'

#### BKIBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    BKIBLKSZ       0014
    BKIDBCCT       0008
    BKIDBCWK       0010
    BKIDBIRQ       000C
    BKIDEVRD       0001 01
    BKIDINFO       002C
    BKIEND         0024
    BKIFLAGS       0001
    BKILOCK        0040
    BKIOFFCP       0004
    BKIOFFST       0018
    BKIRESET       0000 40
    BKIRMPD        0001 04
    BKIRMVMD       0034
    BKISAVBK       0030
    BKISIZE        0064 0000000D
    BKISTART       0020
    BKISTAT        0000
    BKIVDEVA       0028
    BKIVDEVN       001C

This information is based on z/VM V4R3.0. Last updated on 30 Apr 2002 at 15:40:44 EDT.
Copyright IBM Corporation, 1990, 2002