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Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM. |
DHDR
Control Block Contents
DHDR DSECT
Cross Reference (Contains links to field and bit definitions)
DHDR Prolog
Name : HCPDHDR
Description: Directory header block
DSECT : DHDR
Function : This control block points to all of the parts
that make up the object directory.
Located by : SYSDHDR
Created by : HCPDIR
HCPUDTBH
Deleted by : HCPUDS
DHDR Control Block Content
DHDR DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure DHDR Directory header block 0000 0 Bitstring 512 DHDRHDR (0) Fixed-length header portion 0000 0 Signed 4 DHDRSIZE The length of the DHDR block in bytes The version code for the currently online object directory has been created to distinguish between the different styles of the object directory. The "old" style directory is for VM/ESA 1.2.2 and earlier releases. This is Version 0. The Version 1 is the initial "new" style object directory for VM/ESA 2.1.0 release. 0004 4 Bitstring 1 DHDRODVR Version code of object directory 00000000 DHDRODV0 X'00' VM/ESA 1.2.2 and prior version of object directory 00000001 DHDRODV1 X'01' VM/ESA 2.1.0 version of object directory 0005 5 Bitstring 1 * (2) Reserved for IBM use 0007 7 Bitstring 1 DHDRVERS Version code for this block 00000000 DHDRVER0 X'00' Initial version 00000000 * 0008 8 Character 16 DHDRLABL Eye catcher - (CL16'DIRECTORY HEADER') Note that each of the following fields sometimes contains storage addresses, not DASD addresses. DHDRUSER DHDRUID DHDRGID 0018 24 Signed 4 DHDRUSER CCPV/PPPV of userid index start 001C 28 Signed 4 DHDRUID CCPV/PPPV of uid index start 0020 32 Signed 4 DHDRGID CCPV/PPPV of gid index start 0024 36 Signed 4 * (5) Reserved for IBM use (good place for additional index ptrs) 0038 56 Signed 4 DHDRNCBE Count of dir cntrl blck entries 003C 60 Signed 4 * (111) Reserved for IBM use 01F8 504 Character 6 DHDRSRES &SYSRES substitution value 01FE 510 Bitstring 2 * Reserved for IBM use 00000200 DHDRLEN (*-DHDR) Size of fixed-length portion of the DHDR, in bytes 00000040 DHDRSZ (*-DHDR+7)/8 Size of fixed-length portion of the DHDR, in doublewords The directory control block table (DHDRDCBT) contains the DHDRDCBE entries for each control block in the object directory. The order of the DHDRDCBE entries in the table must be the same as the order of the directory control block IDs defined in DHDRDCBI. 0200 512 Dbl-Word 8 DHDRDATA (0) Variable-length portion of DHDR 0200 512 Dbl-Word 8 DHDRDCBT (0) Directory control block table (starts at offset X'200') 0200 512 Character 16 DHDRDCBE (0) Dir control block table entry 0200 512 Signed 4 DHDRDCBS Size (in bytes) of the cntrl blck 0204 516 Bitstring 1 DHDRDCBV Version code for this cntrl blck 00000000 DHDRCBV0 X'00' Initial version 0205 517 Bitstring 1 DHDRDCBF Directory control block flag 00000000 DHDRINIT X'00' Init flag of this dir CB 00000080 DHDRIDGD X'80' The block is contained in DGDBK 00000000 * 0206 518 Signed 2 DHDRDCBI Directory contrl block IDs 00000001 DHDRDHDR 1 DHDR ID 00000002 DHDRDNX1 2 DNXBK ID for USER 1st level index 00000003 DHDRDNX2 3 DNXBK ID for USER 2nd level index 00000004 DHDRDNX3 4 DNXBK ID for UID 1st level index 00000005 DHDRDNX4 5 DNXBK ID for UID 2nd level index 00000006 DHDRDNX5 6 DNXBK ID for GID index 00000007 DHDRDUND 7 DUNDX ID 00000008 DHDRDVMD 8 DVMD ID 00000009 DHDRDDEV 9 DDEV ID 0000000A DHDRDCPU 10 DCPU ID 0000000B DHDRDNSA 11 DNSA ID 0000000C DHDRDAPP 12 DAPPC ID 0000000D DHDRDIUC 13 DIUCV ID 0000000E DHDRDGDB 14 DGDBK ID 0000000F DHDRDGRP 15 DGRPM ID 00000010 DHDRDGSB 16 DGSBK ID 00000011 DHDRDSGR 17 DSGR ID 00000000 * Notes : In order to avoid changing the existing directory control block IDs in DHDRCBI, the new ID should be added at the end with the number of the last directory control block ID in DHDRDCBI plus one. 0208 520 Dbl-Word 8 * Reserved field 0210 528 Character 16 DHDRNXTE (0) Next dir cntrl blck table entry **** THE VALUE OF FSMAXB FOR DATAMAP IS 4072 000000DE DHDRMXTE (FSMAXB-DHDRLEN)/L'DHDRDCBE Maximum number of dir control block table entries 00000DE0 DHDRMXLN (DHDRMXTE*L'DHDRDCBE) Maximum length of DHDRDCBT 00000FE0 DHDRMXBS (DHDRLEN+DHDRMXLN) Maximum DHDR size in bytes 000001FC DHDRMXDS (DHDRMXBS+7)/8 Maximum DHDR size in DBs 00000000 DHDRVLEN 0 Length zero for variable len CB
DHDR Storage Layout
*** DHDR - Directory header block
*
* +---------------------------+------+-------------+------+
* 0 | DHDRSIZE |:RODVR|/////////////|:RVERS|
* +---------------------------+------+-------------+------+
* 8 | DHDRLABL |
* | |
* +---------------------------+---------------------------+
* 18 | DHDRUSER | DHDRUID |
* +---------------------------+---------------------------+
* 20 | DHDRGID |///////////////////////////|
* +---------------------------+///////////////////////////|
* |///////////////////////////////////////////////////////|
* |///////////////////////////////////////////////////////|
* +---------------------------+---------------------------+
* 38 | DHDRNCBE |///////////////////////////|
* +---------------------------+///////////////////////////|
* 40 |///////////////////////////////////////////////////////|
* =///////////////////////////////////////////////////////=
* |///////////////////////////////////////////////////////|
* +-----------------------------------------+-------------+
* 1F8 | DHDRSRES |/////////////|
* +---------------------------+------+------+-------------+
* 200 | DHDRDCBS |:RDCBV|:RDCBF| DHDRDCBI |
* +---------------------------+------+------+-------------+
* 208 |///////////////////////////////////////////////////////|
* +-------------------------------------------------------+
*
*** DHDR - Directory header block
DHDR Cross Reference
Symbol Dspl Value -------------- ---- ----- * 0007 00000000 * 0205 00000000 * 0206 00000000 DHDRCBV0 0204 00000000 DHDRDAPP 0206 0000000C DHDRDATA 0200 DHDRDCBE 0200 DHDRDCBF 0205 DHDRDCBI 0206 DHDRDCBS 0200 DHDRDCBT 0200 DHDRDCBV 0204 DHDRDCPU 0206 0000000A DHDRDDEV 0206 00000009 DHDRDGDB 0206 0000000E DHDRDGRP 0206 0000000F DHDRDGSB 0206 00000010 DHDRDHDR 0206 00000001 DHDRDIUC 0206 0000000D DHDRDNSA 0206 0000000B DHDRDNX1 0206 00000002 DHDRDNX2 0206 00000003 DHDRDNX3 0206 00000004 DHDRDNX4 0206 00000005 DHDRDNX5 0206 00000006 DHDRDSGR 0206 00000011 DHDRDUND 0206 00000007 DHDRDVMD 0206 00000008 DHDRGID 0020 DHDRHDR 0000 DHDRIDGD 0205 00000080 DHDRINIT 0205 00000000 DHDRLABL 0008 DHDRLEN 01FE 00000200 DHDRMXBS 0210 00000FE0 DHDRMXDS 0210 000001FC DHDRMXLN 0210 00000DE0 DHDRMXTE 0210 000000DE DHDRNCBE 0038 DHDRNXTE 0210 DHDRODVR 0004 DHDRODV0 0004 00000000 DHDRODV1 0004 00000001 DHDRSIZE 0000 DHDRSRES 01F8 DHDRSZ 01FE 00000040 DHDRUID 001C DHDRUSER 0018 DHDRVERS 0007 DHDRVER0 0007 00000000 DHDRVLEN 0210 00000000
Last updated on 5 Jun 2001 at 13:22:55 EDT.
Copyright IBM Corporation, 1990, 2001