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 (45) This area reserved for the IORBK. 0168 360 Dbl-Word 8 PAGEXPBK (23) This area reserved for the EXPBK. The area below is used for the Set Paging CCW data. 0220 544 Bitstring 16 PAGSPPAR (0) This area contains the cache CCW data information. 0220 544 Bitstring 10 PAGDATA (0) This is the data area for the Set Paging Parameter CCW. 0220 544 Bitstring 1 * 0221 545 Bitstring 9 PAGDATA1 (0) Defined for the clear move instruction. .... 0221 545 Bitstring 5 * 0226 550 Bitstring 4 PAGCCHH The cylinder/head info. 022A 554 Bitstring 6 * Reserved for IBM use Redefinition of set paging parameter data area for ECKD and FBA paging devices. 0220 544 Bitstring 16 PAGDXDA Define extent data area mapped by DXDA (ECKD) or DFDA (FBA) 00000230 PAGCKSIZ *-PAGBK Actual block size in bytes 00000046 PAGSIZE (((*-PAGBK)+7)/8) PAGBK siz in DWs (leave room for expansion) 00000230 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 = * | | * +-------------------------------------------------------+ * 168 | | * = PAGEXPBK = * | | * +------+----------------------------------+-------------+ * 220 |//////|//////////////////////////////////| PAGCCHH- | * +------+------+---------------------------+-------------+ * 228 | -(226) |/////////////////////////////////////////| * +-------------+-----------------------------------------+ * 230 * *** PAGBK - Page I/O DSECT Block *** Overlay for PAGSPPAR in PAGBK * * +-------------------------------------------------------+ * 220 | PAGDXDA | * | | * +-------------------------------------------------------+ * 230 * *** Overlay for PAGSPPAR in PAGBK
PAGBK Cross Reference
Symbol Dspl Value -------------- ---- ----- PAGBSIZE 0220 00000230 PAGCCHH 0226 PAGCKSIZ 0220 00000230 PAGDATA 0220 PAGDATA1 0221 PAGDXDA 0220 PAGEXPBK 0168 PAGIORBK 0000 PAGSIZE 0220 00000046 PAGSPPAR 0220
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