Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
PAGBK
Control Block Contents
PAGBK DSECT
Cross Reference (Contains links to field and bit definitions)
PAGBK Prolog
NAME : HCPPAGBK DESCRIPTION: Page I/O DSECT Block DSECT : PAGBK FUNCTION : PAGBK maps a 512 byte aligned 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. NOTES : To use this dsect the following dsects must also be included in the module. HCPIORBK, HCPEXPBK.
PAGBK Control Block Content
PAGBK DSECT
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 (57) This area reserved for the IORBK. 01C8 456 Dbl-Word 8 PAGEXPBK (23) This area reserved for the EXPBK. The area below is used for the Set Paging CCW data. 0280 640 Bitstring 16 PAGSPPAR (0) This area contains the cache CCW data information. 0280 640 Bitstring 10 PAGDATA (0) This is the data area for the Set Paging Parameter CCW. 0280 640 Bitstring 1 * 0281 641 Bitstring 9 PAGDATA1 (0) Defined for the clear move instruction. 0281 641 Bitstring 5 * 0286 646 Bitstring 4 PAGCCHH The cylinder/head info. 028A 650 Bitstring 6 * Reserved for IBM use Redefinition of set paging parameter data area for ECKD and FBA paging devices. 0280 640 Bitstring 16 PAGDXDA Define extent data area mapped by DXDA (ECKD) or DFDA (FBA) 00000290 PAGCKSIZ *-PAGBK Actual block size in bytes 00000052 PAGSIZE (((*-PAGBK)+7)/8) PAGBK siz in DWs (leave room for expansion) 00000290 PAGBSIZE *-PAGBK Non theoretical PAGBK size in bytes (leave room for expansion) CKMAINT PAGCKSIZ,GT,512 Check block size
PAGBK Storage Layout
*** PAGBK - Page I/O DSECT Block * * +-------------------------------------------------------+ * 0 | | * = PAGIORBK = * | | * +-------------------------------------------------------+ * 1C8 | | * = PAGEXPBK = * | | * +------+----------------------------------+-------------+ * 280 |//////|//////////////////////////////////| PAGCCHH- | * +------+------+---------------------------+-------------+ * 288 | -(286) |/////////////////////////////////////////| * +-------------+-----------------------------------------+ * 290 * *** PAGBK - Page I/O DSECT Block *** Overlay for PAGSPPAR in PAGBK * * +-------------------------------------------------------+ * 280 | PAGDXDA | * | | * +-------------------------------------------------------+ * 290 * *** Overlay for PAGSPPAR in PAGBK
PAGBK Cross Reference
Symbol Dspl Value -------------- ---- ----- PAGBSIZE 0280 00000290 PAGCCHH 0286 PAGCKSIZ 0280 00000290 PAGDATA 0280 PAGDATA1 0281 PAGDXDA 0280 PAGEXPBK 01C8 PAGIORBK 0000 PAGSIZE 0280 00000052 PAGSPPAR 0280
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