SCBLOCK Back to Index page
 
Prolog 
Control Block Contents 
   SCBLOCK DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This page documents intended Programming Interfaces that
allow the customer to write programs to obtain the services of z/VM.


  SCBLOCK Prolog Top of page
  
 NAME       : SCBLOCK
 DESCRIPTION: Subcommand Control Block
 DSECT      : SCBLOCK
 FUNCTION   : The SCBLOCK describes the dynamic
              entry point for the SUBCOM function and is
              dynamically allocated from free storage by
              DMSITS.
 
 
  SCBLOCK Control Block Content Top of page
  




 SCBLOCK DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      SCBLOCK        Subcommand Control Block
0000    0 Signed       4 SCBFWPTR       CHAIN POINTER TO NEXT SCBLOCK
0004    4 Address      4 SCBWKWRD       AVAILABLE FOR USER INFORMATION
0008    8 Character    8 SCBNAME        NAME OF SUBCOMMAND ENVIRONMENT
0010   16 Dbl-Word     8 SCBPSW (0)     STARTING PSW FOR SUBCOMMAND
0010   16 Bitstring    1 SCBINT         PSW INTERRUPT BITS
      The following table shows the combination of bits
      in SCBPSW that determine what the various INTTYPEs are.
 INTTYPE             |BIT 0|BIT 1|    |BIT 7|HEX value
 --------------------------------------------------------
 NONE                   0     0        0     00
 EXTERNAL               0     0        1     01
 NONCONSOLE             0     1        0     40
 NONCONSOLE & EXTERNAL  0     1        1     41
 CONSOLE                1     0        0     80
 CONSOLE & EXTERNAL     1     0        1     81
 IO                     1     1        0     C0
 ALL                    1     1        1     C1
             NUCX FIELDS.  THESE ARE PRESENT, BUT NOT USED,
             IN SCBLOCKS ON THE NUCSCBLK CHAIN.
0011   17 Bitstring    1 SCBKEY         PSW KEY
0012   18 Bitstring    1 SCBSFLAG       SYSTEM FLAG BYTE.
          1... ....      SCBSFSYS       X'80' SCBSFSYS DENOTES "SYSTEM"
                                        ROUTINE -- WILL NOT BE
                                        AUTOMATICALLY DELETED DURING
                                        ABEND PROCESSING.
          .1.. ....      SCBSFSER       X'40' SCBSFSER DENOTES "SERVICE"
                                        ROUTINE -- WILL BE CALLED WITH
                                        "PURGE" ARGUMENT DURING ABEND
                                        PROCESSING.
          ..1. ....      SCBSFABN       X'20' SCBSFABN USED DURING ABEND
                                        PROCESSING.
          ...1 ....      SCBSFEND       X'10' SCBSFEND DENOTES 'END OF
                                        COMMAND' ROUTINE
          ..1. ....      SCBSFINT       SCBSFABN SCBSFINT USED DURING END
                                        OF COMMAND PROCESSING.
          .... 1...      SCBSPERM       X'08' SCBSPERM DENOTES THAT THIS
                                        NUCLEUS EXTENSION WON'T BE
                                        DELETED DURING NUCXDROP ALL
                                        PROCESS
          .... .1..      SCBSFIMM       X'04' SCBSFIMM DENOTES THAT THIS
                                        NUCLEUS EXTENSION CAN ALSO BE
                                        CALLED AS AN IMMEDIATE COMMAND
          .... ..1.      SCBSFX         X'02' SCBSFX DENOTES A LOOK-ASIDE
                                        ENTRY POINTING TO A REAL CMS
                                        NUCLEUS ROUTINE.
          .... ...1      SCBSHIDE       X'01' SCBSHIDE USED TO HIDE A
                                        NUCLEUS EXTENSION TEMPORARILY.
0013   19 Bitstring    1 SCBUFLAG       USER FLAG BYTE.
0014   20 Address      4 SCBENTR        ENTRY POINT ADDRESS IN PSW
0018   24 Address      4 SCBXORG        ADDRESS WHERE NUCLEUS EXTENSION
                                        WAS LOADED IN FREE STORAGE.
001C   28 Signed       4 SCBXLEN        LENGTH IN BYTES OF NUCLEUS
                                        EXTENSION. MAY BE ZERO FOR
                                        SECONDARY ENTRY POINTS.
0020   32 Bitstring    1 SCBSFLG2       F*2 SECOND FLAG BYTE
          1... ....      SCBSFA31       X'80' SCBSFA31 EXTENSION IS AMODE
                                        31
          .1.. ....      SCBSFA24       X'40' SCBSFA24 EXTENSION IS AMODE
                                        24
          ..1. ....      SCBSFSEG       X'20' SCBSFSEG SEGMENT RESIDENT
                                        WHEN BOTH ON, EXTENSION IS AMODE
                                        ANY, WHEN BOTH OFF, EXTENSION IS
                                        AMODE SAME.
          ...1 ....      SCBSFUNC       X'10' SCBSFUNC Indicate function
                                        can not be S5U29592 invoked from
                                        the command line
          .... 1...      SCBSMT         X'08' SCBSMT mt subcom
          .... .1..      SCBSTPRV       X'04' SCBSTPRV thread private
                                        subcom
0021   33 Bitstring    1 * (3)          RESERVED FOR FURTURE USE
0024   36 Character    8 SCBSEGID       LOGICAL SEGMENT IDENTIFIER
002C   44 Signed       4 SCBTESTK       thread execomm stack
0030   48 Dbl-Word     8 * (0)          KEEP DOUBLEWORD ALIGNED
          00000030       SCBLOCKB       *-SCBLOCK LENGTH IN BYTES
          00000006       SCBLOCKD       (SCBLOCKB+7)/8 LENGTH IN DWORD
 
 
  SCBLOCK Storage Layout Top of page
  
          
*** SCBLOCK - Subcommand Control Block
*
*     +---------------------------+---------------------------+
*   0 |         SCBFWPTR          |         SCBWKWRD          |
*     +---------------------------+---------------------------+
*   8 |                       SCBNAME                         |
*     +------+------+------+------+---------------------------+
*  10 |SCBINT|SCBKEY|:SFLAG|:UFLAG|         SCBENTR           |
*     +------+------+------+------+---------------------------+
*  18 |         SCBXORG           |         SCBXLEN           |
*     +------+--------------------+---------------------------+
*  20 |:SFLG2|////////////////////|        SCBSEGID-          |
*     +------+--------------------+---------------------------+
*  28 |          -(024)           |         SCBTESTK          |
*     +---------------------------+---------------------------+
*  30
*
*** SCBLOCK - Subcommand Control Block
 
 
  SCBLOCK Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
SCBENTR        0014
SCBFWPTR       0000
SCBINT         0010
SCBKEY         0011
SCBLOCKB       0030 00000030
SCBLOCKD       0030 00000006
SCBNAME        0008
SCBPSW         0010
SCBSEGID       0024
SCBSFABN       0012 20
SCBSFA24       0020 40
SCBSFA31       0020 80
SCBSFEND       0012 10
SCBSFIMM       0012 04
SCBSFINT       0012 20
SCBSFLAG       0012
SCBSFLG2       0020
SCBSFSEG       0020 20
SCBSFSER       0012 40
SCBSFSYS       0012 80
SCBSFUNC       0020 10
SCBSFX         0012 02
SCBSHIDE       0012 01
SCBSMT         0020 08
SCBSPERM       0012 08
SCBSTPRV       0020 04
SCBTESTK       002C
SCBUFLAG       0013
SCBWKWRD       0004
SCBXLEN        001C
SCBXORG        0018
 
This information is based on z/VM 7.4.0 Last updated on 24 Jun 2024 at 11:37:49 EDT.
Copyright IBM Corporation, 1990, 2024