CPTBK | Back to Index page

| Prolog Control Block Contents CPTBK DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

CPTBK Prolog | Top of page

     NAME       : HCPCPTBK
     DESCRIPTION: Channel program initialization block
     DSECT      : CPTBK
     FUNCTION   : To map the common channel program init. block
     LOCATED BY :
                  RDCCPTA field in the HCPRDC Block.
     CREATED BY : CPTBK'S are static and are created by invocations
                  of the HCPCPTBL macro within module HCPCPG.
     DELETED BY : CPTBK'S are not deleted.
     SERIALIZED : NONE.
     RELOCATION CONSIDERATIONS : None

CPTBK Control Block Content | Top of page

     CPTBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      CPTBK          Channel program initialization block
    0000    0 Dbl-Word     8 * (0)          Start of channel prog init. block
                                            Read Label
    0000    0 Signed       4 RDLBS          Read Label CP Size
    0004    4 Address      4 RDLBA          Read Label CP Entry Point Read
                                            Alloc Map
    0008    8 Signed       4 RALOCS         Read Alloc CP Size
    000C   12 Address      4 RALOCA         Read Alloc CP Entry Point Read
                                            Alloc Map Metadata
    0010   16 Signed       4 RALMTS         Read Alloc Meta CP size
    0014   20 Address      4 RALMTA         Read Alloc Meta CP Entry Pt.
                                            Write Label
    0018   24 Signed       4 WRTLBS         Write Label CP Size
    001C   28 Address      4 WRTLBA         Write Label CP Entry Point Write
                                            Alloc Map
    0020   32 Signed       4 WALOCS         Write Alloc CP Size
    0024   36 Address      4 WALOCA         Write Alloc CP Entry Point Erase
                                            Extent
    0028   40 Signed       4 EREXTS         Erase Extent CP Size
    002C   44 Address      4 EREXTA         Erase Extent CP Entry Point
                                            Unload Buffer
    0030   48 Signed       4 UNLODS         Unload Buffer CP Size
    0034   52 Address      4 UNLODA         Unload Buffer CP Entry Point
                                            Sense Id
    0038   56 Signed       4 SNSIDS         Sense ID CP Size
    003C   60 Address      4 SNSIDA         Sense ID CP Entry Point Perform
                                            Subsystem Function
    0040   64 Signed       4 PSFS           PSF CP Size
    0044   68 Address      4 PSFA           PSF CP Entry Point
    0048   72 Bitstring    1 CPARCH         Device Arch
              1... ....      CPFBA          X'80' Device Arch is DASD/FBA
              .1.. ....      CPCKD          X'40' Device Arch is DASD/CKD
              ..1. ....      CPECKD         X'20' Device Arch is DASD/ECKD
              ...1 ....      CPCKDE         X'10' Device Arch is DASD/CKD-E
              .... 1...      CPTAPE         X'08' Device Arch is TAPE
    0049   73 Bitstring    3 *              Reserved
              0000004C       CPBTSZ         (*-CPTBK) Number of bytes
              0000000A       CPTSIZE        (*-CPTBK+7)/8 Number of
                                            doublewords

CPTBK Storage Layout | Top of page

    *** CPTBK - Channel program initialization block
    *
    *     +---------------------------+---------------------------+
    *   0 |          RDLBS            |          RDLBA            |
    *     +---------------------------+---------------------------+
    *   8 |          RALOCS           |          RALOCA           |
    *     +---------------------------+---------------------------+
    *  10 |          RALMTS           |          RALMTA           |
    *     +---------------------------+---------------------------+
    *  18 |          WRTLBS           |          WRTLBA           |
    *     +---------------------------+---------------------------+
    *  20 |          WALOCS           |          WALOCA           |
    *     +---------------------------+---------------------------+
    *  28 |          EREXTS           |          EREXTA           |
    *     +---------------------------+---------------------------+
    *  30 |          UNLODS           |          UNLODA           |
    *     +---------------------------+---------------------------+
    *  38 |          SNSIDS           |          SNSIDA           |
    *     +---------------------------+---------------------------+
    *  40 |           PSFS            |           PSFA            |
    *     +------+--------------------+---------------------------+
    *  48 |CPARCH|////////////////////| 4C
    *     +------+--------------------+
    *
    *** CPTBK - Channel program initialization block

CPTBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    CPARCH         0048
    CPBTSZ         0049 0000004C
    CPCKD          0048 40
    CPCKDE         0048 10
    CPECKD         0048 20
    CPFBA          0048 80
    CPTAPE         0048 08
    CPTSIZE        0049 0000000A
    EREXTA         002C
    EREXTS         0028
    PSFA           0044
    PSFS           0040
    RALMTA         0014
    RALMTS         0010
    RALOCA         000C
    RALOCS         0008
    RDLBA          0004
    RDLBS          0000
    SNSIDA         003C
    SNSIDS         0038
    UNLODA         0034
    UNLODS         0030
    WALOCA         0024
    WALOCS         0020
    WRTLBA         001C
    WRTLBS         0018

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:27:27 EDT.
Copyright IBM Corporation, 1990, 2020