HYPMAP Back to Index page
 
Prolog 
Control Block Contents 
   HYPMAP DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  HYPMAP Prolog Top of page
 
 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 Top of page
 

 HYPMAP DSECT Top of page
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 Top of page
 
          
*** HYPMAP - Hyperblock Mapping Table
*
*     +---------------------------+---------------------------+
*   0 |         HYPMSIZE          |         HYPMENTS          |
*     +-------------+-------------+---------------------------+
*   8 |  HYPMBLKC   |/////////////|         HYPMAHYP          |
*     +-------------+-------------+---------------------------+
*  10 |         HYPMFN1           |         HYPMFN2           |
*     +---------------------------+---------------------------+
*  18 |         HYPMFT1           |         HYPMFT2           |
*     +---------------------------+---------------------------+
*
*** HYPMAP - Hyperblock Mapping Table
 
 
  HYPMAP Cross Reference Top of page
 
 
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
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 16:01:22 EDT.
Copyright IBM Corporation, 1990, 2022