PAGBK Back to Index page
 
Prolog 
Control Block Contents 
   PAGBK 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.


  PAGBK Prolog Top of page
 
 NAME       : HCPPAGBK
 DESCRIPTION: Page I/O DSECT Block
 DSECT      : PAGBK
 FUNCTION   : PAGBK maps a free storage block that contains
              the IORBK, EXPBK (for single exposures), and
              the Set Paging Parameter CCW or the Define
              Extent Data Area.
 LOCATED BY : EXPIORBK - Field in the exposure block that points
              to the beginning of the block.
 RELOCATION CONSIDERATIONS : None
 NOTES      : To use this dsect the following dsects must also
              be included in the module. HCPIORBK, HCPEXPBK.
              This block contains an IORBK and CCW data.  It must
              be backed below 2-Gig.  (Defaulted in CBITABLE).
 
 
  PAGBK Control Block Content Top of page
 

 PAGBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure PAGBK Page I/O DSECT Block Beginning of the IORBK for this exposure. 0000 0 Dbl-Word 8 PAGIORBK (83) This area reserved for the IORBK. 0298 664 Dbl-Word 8 PAGEXPBK (54) This area reserved for the EXPBK. The area below is used for the Set Paging CCW data. 0448 1096 Bitstring 32 PAGSPPAR (0) This area contains the cache CCW data information. 0448 1096 Bitstring 10 PAGDATA (0) This is the data area for the Set Paging Parameter CCW. 0448 1096 Bitstring 1 * 0449 1097 Bitstring 9 PAGDATA1 (0) Defined for the clear move instruction. 0449 1097 Bitstring 5 * 044E 1102 Bitstring 4 PAGCCHH The cylinder/head info. 0452 1106 Bitstring 22 * Reserved for IBM use Redefinition of set paging parameter data area for ECKD and FBA paging devices. 0448 1096 Bitstring 32 PAGDXDA Define extent data area mapped by DXDA (ECKD) or DFDA (FBA) 00000468 PAGCKSIZ *-PAGBK Actual block size in bytes 0000008D PAGSIZE (((*-PAGBK)+7)/8) PAGBK siz in DWs (leave room for expansion) 00000468 PAGBSIZE *-PAGBK Non theoretical PAGBK size in bytes (leave room for expansion)
 
 
  PAGBK Storage Layout Top of page
 
          
*** PAGBK - Page I/O DSECT Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       PAGIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 298 |                                                       |
*     =                       PAGEXPBK                        =
*     |                                                       |
*     +------+----------------------------------+-------------+
* 448 |//////|//////////////////////////////////|  PAGCCHH-   |
*     +------+------+---------------------------+-------------+
* 450 |   -(44E)    |/////////////////////////////////////////|
*     +-------------+/////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
* 468
*
*** PAGBK - Page I/O DSECT Block
          
*** Overlay for PAGSPPAR in PAGBK
*
*     +-------------------------------------------------------+
* 448 |                                                       |
*     =                       PAGDXDA                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 468
*
*** Overlay for PAGSPPAR in PAGBK
 
 
  PAGBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
PAGBSIZE       0448 00000468
PAGCCHH        044E
PAGCKSIZ       0448 00000468
PAGDATA        0448
PAGDATA1       0449
PAGDXDA        0448
PAGEXPBK       0298
PAGIORBK       0000
PAGSIZE        0448 0000008D
PAGSPPAR       0448
 
This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:29:30 EDT.
Copyright IBM Corporation, 1990, 2020