IBM: LEDA

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.

LEDA

Prolog

Control Block Contents

LEDA DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

LEDA Prolog

 Name       : HCPLEDA
 Description: Locate Record Extended data area
 STATUS     : VM/ESA Version 2, Release 4.0
 DSECT      : LEDA
 Function   : Maps the contents of the Locate Record
              Extended data area.
 Located by :
              HCCWADDR - The Locate Record Extended CCW data
              address field contains the address of
              the locate record extended data area.
 Created by :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build ECKD channel programs
              which is allocated in modules HCPFTU/HCPFTP.
 Deleted by :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build ECKD channel programs
              which is deallocated in modules HCPFTU/HCPFTP.
 Serialized :
              Track cache manager -
              TCMTSLK  - Track cache lock
 Comments   :
              Track cache manager -
              None

LEDA Control Block Content


LEDA DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      LEDA           Locate Record Extended data area
0000    0 Bitstring   16 LEDAREA (0)    Locate Record Extended data area
     Byte 0 (Operation byte)
     Although defined as BITs, the contents of the operation byte are,
     architecturally, multiple codes.
0000    0 Bitstring    1 LEDOP          Operation byte
          11.. ....      LEDOR          X'C0' Operation byte, bits 0 and
                                        1 ------- Codes for use with
                                        LEDOR
          .... ....      LEDORCA        X'00' Orient on count area
          .1.. ....      LEDORHA        X'40' Orient on home address
          1... ....      LEDORDA        X'80' Orient on data area
          11.. ....      LEDORIX        X'C0' Orient on index -------
          ..11 1111      LEDOOC         X'3F' Operation byte, bits 2
                                        through 7 ------- Codes for use
                                        with LEDOOC
          .... ...1      LEDOCWD        X'01' Write data
          .... ..11      LEDOCFW        X'03' Format write
          .... .11.      LEDOCRD        X'06' Read data
          .... 1.11      LEDOCWT        X'0B' Write track
          .... 11..      LEDOCRT        X'0C' Read tracks
          ...1 .11.      LEDOCR         X'16' Read
          ..11 1111      LEDOCX         X'3F' Extended Op Code -------
     Byte 1 (Auxiliary byte)
0001    1 Bitstring    1 LEDAUX         Auxiliary byte
          1... ....      LEDAVTLF       X'80' Validate transfer length
                                        factor
          .... ...1      LEDARCS        X'01' Read count suffix
     Byte 2 (Zeros)
0002    2 Bitstring    1 LEDZEROS       Must be zeros
     Byte 3 (Count)
0003    3 Bitstring    1 LEDCOUNT       Count
     Bytes 4 through 7 (Seek address)
0004    4 Bitstring    4 LEDSEEK (0)    Seek address (CCHH)
0004    4 Bitstring    2 LEDSCC         CC of CCHH
0006    6 Bitstring    2 LEDSHH         HH of CCHH
     Bytes 8 through 12 (Search argument)
0008    8 Bitstring    5 LEDSRCH (0)    Search argument (CCHHR)
0008    8 Bitstring    2 LEDRCC         CC of CCHHR
000A   10 Bitstring    2 LEDRHH         HH of CCHHR
000C   12 Bitstring    1 LEDRR          R of CCHHR
     Byte 13 (Sector number)
000D   13 Bitstring    1 LEDSECT        Sector number
          1111 1111      LEDNOSCT       X'FF' Sector orientation not
                                        performed
     Bytes 14 and 15 (Transfer length factor)
000E   14 Bitstring    2 LEDTLF         Transfer length factor
     Byte 16 (Reserved)
0010   16 Bitstring    1 LEDRES         Reserved for IBM use
     Byte 17 (Extended Operation)
0011   17 Bitstring    1 LEDEOP         Extended Operation
          .... ....      LEDOTHOP       X'00' Use operation code in byte
                                        0
          .... 1..1      LEDWRANY       X'09' Write Any
          .... 1.1.      LEDRDANY       X'0A' Read Any
          .... 111.      LEDRDTKS       X'0E' Read Trackset
          ...1 ....      LEDPRETS       X'10' Prestage Trackset
          ...1 ...1      LEDWRTKS       X'11' Write Trackset
          ...1 ..11      LEDUWRTK       X'13' Update Write Trackset
     Bytes 18-19 (Extended Parameter Length)
0012   18 Bitstring    2 LEDEPLEN       Extended Parameter Length
     Bytes 20-21 (Extended Parameter)
0014   20 Bitstring    1 LEDEPRM1       Extended Parameter byte 1
0015   21 Bitstring    1 LEDEPRM2       Extended Parameter byte 2
     Length equates
          00000016       LEDBSIZE       *-LEDAREA Size of LEDA in bytes
          00000003       LEDSIZE        ((*-LEDAREA)+7)/8 Size of LEDA in
                                        DWs

LEDA Storage Layout

*** LEDA - Locate Record Extended data area
*
*     +------+------+------+------+-------------+-------------+
*   0 |LEDOP |LEDAUX|:ZEROS|:COUNT|   LEDSCC    |   LEDSHH    |
*     +------+------+------+------+------+------+-------------+
*   8 |   LEDRCC    |   LEDRHH    |LEDRR |:SECT |   LEDTLF    |
*     +------+------+-------------+------+------+-------------+
*  10 |LEDRES|LEDEOP|  LEDEPLEN   |:EPRM1|:EPRM2| 16
*     +------+------+-------------+------+------+
*
*** LEDA - Locate Record Extended data area