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. This block contains an IORBK and CCW data. It must backed below 2-Gig. (Defaulted in CBITABLE).
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 (65) This area reserved for the IORBK. 0208 520 Dbl-Word 8 PAGEXPBK (25) This area reserved for the EXPBK. The area below is used for the Set Paging CCW data. 02D0 720 Bitstring 32 PAGSPPAR (0) This area contains the cache CCW data information. 02D0 720 Bitstring 10 PAGDATA (0) This is the data area for the Set Paging Parameter CCW. 02D0 720 Bitstring 1 * 02D1 721 Bitstring 9 PAGDATA1 (0) Defined for the clear move instruction. 02D1 721 Bitstring 5 * 02D6 726 Bitstring 4 PAGCCHH The cylinder/head info. 02DA 730 Bitstring 22 * Reserved for IBM use Redefinition of set paging parameter data area for ECKD and FBA paging devices. 02D0 720 Bitstring 32 PAGDXDA Define extent data area mapped by DXDA (ECKD) or DFDA (FBA) 000002F0 PAGCKSIZ *-PAGBK Actual block size in bytes 0000005E PAGSIZE (((*-PAGBK)+7)/8) PAGBK siz in DWs (leave room for expansion) 000002F0 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 = * | | * +-------------------------------------------------------+ * 208 | | * = PAGEXPBK = * | | * +------+----------------------------------+-------------+ * 2D0 |//////|//////////////////////////////////| PAGCCHH- | * +------+------+---------------------------+-------------+ * 2D8 | -(2D6) |/////////////////////////////////////////| * +-------------+/////////////////////////////////////////| * |///////////////////////////////////////////////////////| * |///////////////////////////////////////////////////////| * +-------------------------------------------------------+ * 2F0 * *** PAGBK - Page I/O DSECT Block *** Overlay for PAGSPPAR in PAGBK * * +-------------------------------------------------------+ * 2D0 | | * = PAGDXDA = * | | * +-------------------------------------------------------+ * 2F0 * *** Overlay for PAGSPPAR in PAGBK
PAGBK Cross Reference
Symbol Dspl Value -------------- ---- ----- PAGBSIZE 02D0 000002F0 PAGCCHH 02D6 PAGCKSIZ 02D0 000002F0 PAGDATA 02D0 PAGDATA1 02D1 PAGDXDA 02D0 PAGEXPBK 0208 PAGIORBK 0000 PAGSIZE 02D0 0000005E PAGSPPAR 02D0
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