IBM: DUCT

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.

DUCT

Prolog

Control Block Contents

DUCT DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

DUCT Prolog

 Name       : HCPDUCT
 Description: Dispatchable Unit Control Table
 Status     : VM/ESA Version 2, Release 4.0
 DSECT      : DUCT
 Function   : The DUCT maps the storage associated with the
              Dispatchable Unit Control Table
 Located by : The DUCTO in CR2
 Created by : None.
 Deleted by : None.
 References : None.
 Serialized : When used to map a guest DUCT, the DUCT is serialized by
              instruction stream serialization.
 Notes      : None.

DUCT Control Block Content


DUCT DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      DUCT           Dispatchable Unit Control Table
0000    0 Signed       4 DUIBM1         Reserved for IBM use
0004    4 Signed       4 DUIBM2         Reserved for IBM use
0008    8 Signed       4 *              Reserved for IBM use
000C   12 Signed       4 DUIBM4         Reserved for IBM use
0010   16 Signed       4 DUALD          Dispatchable-Unit Access- List
                                        Designation
0014   20 Bitstring    8 *              Reserved for IBM use
001C   28 Signed       4 DUPRGM         For use by programming
0020   32 Signed       4 DUBSAADR       BSA addr mode & return addr First
                                        bit of the DUBSAADR field
          1... ....      DUBSAADM       X'80' BSA address mode bit
0024   36 Signed       4 DUBSAPSW       PSW info for BSA instruction
0028   40 Bitstring    4 *              Reserved for IBM use
002C   44 Address      4 DUTRPCTL       Addr of Trap-Control-Block
0030   48 Bitstring   16 *              Reserved for IBM use
          00000040       DUCTLEN        *-DUCT Length in bytes
          00000008       DUCTSIZE       (*-DUCT+7)/8 Length in
                                        doublewords
     Redefinition of Word 9
0024   36 Bitstring    2 DUBSAPKM       PSW key mask
0026   38 Bitstring    1 *              Reserved for IBM use
0027   39 Bitstring    1 DUBSAPS1       Misc PSW stuff
          1111 ....      DUBSAPSK       X'F0' PSW key
          .... 1...      DUBSARA        X'08' Reduced authority bit EQU
                                        X'04' Reserved EQU X'02' Reserved
          .... ...1      DUBSAPSB       X'01' Problem state bit

DUCT Storage Layout

*** DUCT - Dispatchable Unit Control Table
*
*     +---------------------------+---------------------------+
*   0 |          DUIBM1           |          DUIBM2           |
*     +---------------------------+---------------------------+
*   8 |///////////////////////////|          DUIBM4           |
*     +---------------------------+---------------------------+
*  10 |          DUALD            |///////////////////////////|
*     +---------------------------+---------------------------+
*  18 |///////////////////////////|          DUPRGM           |
*     +---------------------------+---------------------------+
*  20 |         DUBSAADR          |         DUBSAPSW          |
*     +---------------------------+---------------------------+
*  28 |///////////////////////////|         DUTRPCTL          |
*     +---------------------------+---------------------------+
*  30 |///////////////////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
*  40
*
*** DUCT - Dispatchable Unit Control Table
*** Overlay for DUBSAPSW in DUCT
*
*                                 +-------------+------+------+
*  20 ...                      24 |  DUBSAPKM   |//////|:SAPS1|
*                                 +-------------+------+------+
*  28
*
*** Overlay for DUBSAPSW in DUCT