Programming Interface Information:
This information is NOT
intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only. |
HYPMAP
Cross Reference (Contains links to field and bit definitions)
HYPMAP Prolog
Name : HYPMAP Description: Hyperblock Mapping Table DSECT : HYPMAP Function : HYPMAP is the hyperblock mapping table for read-only disks. It contains a header plus an entry for each 4K page of hyperblocks (or FSTs for a STAT) associated with the accessed disk. HYPMAP is used mainly by file management to reduce the paging overhead when searching for a file on a read-only disk. HYPMAP is called by the HYPMAP macro.
HYPMAP Control Block Content
HYPMAP DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure HYPMAP Hyperblock Mapping Table H E A D E R 0000 0 Signed 4 HYPMSIZE Size of table (DWORDS) 0004 4 Signed 4 HYPMENTS Number of entries in table 00000001 HYPMHSIZ (*-HYPMAP+7)/8 Size of header (DWORDS) T A B L E E N T R I E S 0008 8 Signed 4 HYPTAB (0) Start of table 0008 8 Signed 2 HYPMBLKC Number of hyperblocks/FST's on the page mapped by this table entry 000A 10 Signed 2 * ** Unused ** 000C 12 Address 4 HYPMAHYP Pointer to hyperblock 0010 16 Character 16 HYPMFID (0) ID of last file in this block 0010 16 Character 8 HYPMFN (0) Filename 0010 16 Character 4 HYPMFN1 First half of filename 0014 20 Character 4 HYPMFN2 Second half of filename 0018 24 Character 8 HYPMFT (0) Filetype 0018 24 Character 4 HYPMFT1 First half of filetype 001C 28 Character 4 HYPMFT2 Second half of filetype 0020 32 Character 1 HYPMNEXT (0) Start of next entry 00000018 HYPMLEN *-HYPTAB Length of table entry
HYPMAP Storage Layout
*** HYPMAP - Hyperblock Mapping Table * * +---------------------------+---------------------------+ * 0 | HYPMSIZE | HYPMENTS | * +-------------+-------------+---------------------------+ * 8 | HYPMBLKC |/////////////| HYPMAHYP | * +-------------+-------------+---------------------------+ * 10 | HYPMFN1 | HYPMFN2 | * +---------------------------+---------------------------+ * 18 | HYPMFT1 | HYPMFT2 | * +---------------------------+---------------------------+ * 20 | | * = HYPMNEXT = * | | * +-------------------------------------------------------+ * *** HYPMAP - Hyperblock Mapping Table
HYPMAP Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----HYPMAHYP 000C
HYPMBLKC 0008
HYPMENTS 0004
HYPMFID 0010
HYPMFN 0010
HYPMFN1 0010
HYPMFN2 0014
HYPMFT 0018
HYPMFT1 0018
HYPMFT2 001C
HYPMHSIZ 0004 00000001
HYPMLEN 0020 00000018
HYPMNEXT 0020
HYPMSIZE 0000
HYPTAB 0008
Last updated on 12 Aug 1999 at 11:21:26 EDT.
Copyright IBM Corporation, 1990, 1999