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 7.3.0 Last updated on 22 Jun 2022 at 15:48:21 EDT.
Copyright IBM Corporation, 1990, 2022