SCBLOCK

Prolog  

Control Block Contents  
   SCBLOCK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

SCBLOCK Prolog

 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

SCBLOCK DSECT

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' DENOTES "SYSTEM" ROUTINE --
                                        WILL NOT BE AUTOMATICALLY DELETED
                                        DURING ABEND PROCESSING.
          .1.. ....      SCBSFSER       X'40' DENOTES "SERVICE" ROUTINE
                                        -- WILL BE CALLED WITH "PURGE"
                                        ARGUMENT DURING ABEND PROCESSING.
          ..1. ....      SCBSFABN       X'20' USED DURING ABEND
                                        PROCESSING.
          ...1 ....      SCBSFEND       X'10' DENOTES 'END OF COMMAND'
                                        ROUTINE
          ..1. ....      SCBSFINT       SCBSFABN USED DURING END OF
                                        COMMAND PROCESSING.
          .... 1...      SCBSPERM       X'08' DENOTES THAT THIS NUCLEUS
                                        EXTENSION WON'T BE DELETED DURING
                                        NUCXDROP ALL PROCESS
          .... .1..      SCBSFIMM       X'04' DENOTES THAT THIS NUCLEUS
                                        EXTENSION CAN ALSO BE CALLED AS
                                        AN IMMEDIATE COMMAND
          .... ..1.      SCBSFX         X'02' DENOTES A LOOK-ASIDE ENTRY
                                        POINTING TO A REAL CMS NUCLEUS
                                        ROUTINE.
          .... ...1      SCBSHIDE       X'01' 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' EXTENSION IS AMODE 31
          .1.. ....      SCBSFA24       X'40' EXTENSION IS AMODE 24
          ..1. ....      SCBSFSEG       X'20' SEGMENT RESIDENT WHEN BOTH
                                        ON, EXTENSION IS AMODE ANY, WHEN
                                        BOTH OFF, EXTENSION IS AMODE
                                        SAME.
          ...1 ....      SCBSFUNC       X'10' Indicate function can not
                                        be S5U29592 invoked from the
                                        command line
          .... 1...      SCBSMT         X'08' mt subcom
          .... .1..      SCBSTPRV       X'04' 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

          
*** 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

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