|
Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
XSUBK
Control Block Contents
XSUBK DSECT
Cross Reference (Contains links to field and bit definitions)
XSUBK Prolog
NAME : HCPXSUBK
DESCRIPTION: Expanded Storage Usability Map
DSECT : XSUBK
FUNCTION : This map is used to keep track of the allocation
of Expanded Storage. Each map corresponds to one
increment of XSTORE and can therefore represent
up to 64Meg of expanded storage.
LOCATED BY : XDRUMAPT located in the HCPXDRBK.
CREATED BY : HCPESCDI during initialization processing.
DELETED BY : HCPESCDI if no expanded storage is configured
to the system.
XSUBK Control Block Content
XSUBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure XSUBK Expanded Storage Usability Map
The following are bit maps that represents the
allocation of one increment of Expanded Storage
(up to 64 megabytes).
Each bit position represents the allocation state
of a block of XSTORE.
0000 0 Bitstring 1 XSUALMAP (2048)
XSTORE availability map. When a
bit's value is "1" then the
corresponding block is allocated.
0800 2048 Bitstring 1 XSUERMAP (2048)
XSTORE error map. When a bit's
value is "1" then the
corresponding block is in error.
XSUBK Storage Layout
*** XSUBK - Expanded Storage Usability Map
*
* +-------------------------------------------------------+
* 0 | |
* = XSUALMAP =
* | |
* +-------------------------------------------------------+
* 800 | |
* = XSUERMAP =
* | |
* +-------------------------------------------------------+
*1000
*
*** XSUBK - Expanded Storage Usability Map
XSUBK Cross Reference
Symbol Dspl Value -------------- ---- ----- XSUALMAP 0000 XSUERMAP 0800
Copyright IBM Corporation, 1990, 2007