MODHDCB

Prolog  

Control Block Contents  
   MODHDCB DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

MODHDCB Prolog

 Name       : MODHDCB
 Description: Module Header Control Block
 DSECT      : MODHDCB
 Notes      : This macro describes the first record,
              called the header record, in a CMS Module file.
              This header is 80 bytes long and exists in
              variable format record file system module files
              and all byte file system module files.

MODHDCB Control Block Content

MODHDCB DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      MODHDCB        Module Header Control Block
0000    0 Character   40 NUCONMAP       1st 40 bytes mapped by NUCON
0000    0 Signed       4 STARTADR       Start Location
0004    4 Signed       4 XFRSTLOC       Beginning location in storage
0008    8 Signed       4 XLASTLOC       Ending location in storage
000C   12 Signed       4 XLOCCNT        Location counter
0010   16 Character   16 RSVD0          Reserved
0020   32 Bitstring    4 XLDRFLGS       Module flag
0020   32 Bitstring    1 XLDRNOER
          .... .1..      NOERASE        X'04'
          .... ...1      SYSTEM         X'01'
0021   33 Bitstring    1 XLDRSTRN
          1... ....      STRINIT        X'80'
0022   34 Bitstring    2 RESERVED
0024   36 Character    4 RSVD1          Reserved and must be zero
0028   40 Bitstring    2 TABLENT        # Loader Table Entries
002A   42 Character    1 POFLAG         X'80' nucon uses as UNRES flag
          .1.. ....      ISAPO          X'40' Module is a program object
002B   43 Bitstring    1 MODFLAG        Module flag
          1... ....      NOLOADMF       X'80' Indicates 'No Load Map'
          .1.. ....      CLEAROPT       X'40' CLEAR option flag
          ..1. ....      MODDOS         X'20' Generated with DOS option
          ...1 ....      MODALL         X'10' Generated with ALL option
          .... ..1.      MAP24BYT       X'02' Map entries are 24 bytes
          .... ...1      POSTXA         X'01' Module gen'd by CMS 5.5 or
                                        later
002C   44 Bitstring    1 MODEFLAG       AMODE/RMODE flag
          1... ....      AMODE31        X'80' Indicates an AMODE of 31
          .1.. ....      AMODE24        X'40' Indicates an AMODE of 24
          11.. ....      AMODEANY       X'C0' Indicates an AMODE of ANY
          ..1. ....      RMODEANY       X'20' Indicates an RMODE of ANY
          ...1 ....      RMODE24        X'10' Indicates an RMODE of 24
002D   45 Bitstring    1 RLDFLAG        Relocation flag
          1... ....      RELODATA       X'80' RLD data does exist
          .1.. ....      FORMAT31       X'40' 31 bit RLD entries
          ..1. ....      TWORLD         X'20' 2 RLD recs in file
          ...1 ....      CLEANMOD       X'10' Cleanup module at end of
                                        svc
          .... 1...      FIXDTRNS       X'08' Fixed transient area module
002E   46 Bitstring    1 ARCFLAG        Architecture flag
          1... ....      INVLD370       X'80' 370 architecture is invalid
          .1.. ....      INVALXA        X'40' XA architecture is invalid
          ..1. ....      INVALXC        X'20' XC architecture is invalid
002F   47 Bitstring    1 *              Reserved
0030   48 Bitstring    2 RLDRECS        Number of RLD records in the
                                        module
0032   50 Bitstring    2 LRLDBYTS       Number of bytes in last rld
                                        record - bfs files only
0034   52 Signed       4 HISTSIZE       Size of the history data in bytes
                                        - bfs files only
0038   56 Bitstring    2 ICATCH         Module eye catcher for DMSEXC
003A   58 Bitstring    2 POREC          First PO record number
0040   64 Dbl-Word     8 * (0)
          00000040       MODHDLEN       *-MODHDCB MODHDCB length in bytes
          00000008       MODDBLEN       (MODHDLEN+7)/8 MODHDCB length in
                                        dw

MODHDCB Storage Layout

          
*** MODHDCB - Module Header Control Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       NUCONMAP                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  28
*
*** MODHDCB - Module Header Control Block
          
*** Overlay for NUCONMAP in MODHDCB
*
*     +---------------------------+---------------------------+
*   0 |         STARTADR          |         XFRSTLOC          |
*     +---------------------------+---------------------------+
*   8 |         XLASTLOC          |         XLOCCNT           |
*     +---------------------------+---------------------------+
*  10 |                        RSVD0                          |
*     |                                                       |
*     +---------------------------+---------------------------+
*  20 |         XLDRFLGS          | 24
*     +---------------------------+
*
*** Overlay for NUCONMAP in MODHDCB
          
*** Overlay for XLDRFLGS in MODHDCB
*
*     +------+------+-------------+---------------------------+
*  20 |:RNOER|:RSTRN|/////////////|          RSVD1            |
*     +------+------+------+------+------+------+------+------+
*  28 |  TABLENT    |POFLAG|:FLAG |:EFLAG|:FLAG |:FLAG |//////|
*     +-------------+------+------+------+------+------+------+
*  30 |  RLDRECS    |  LRLDBYTS   |         HISTSIZE          |
*     +-------------+-------------+---------------------------+
*  38 |   ICATCH    |   POREC     |///////////////////////////|
*     +-------------+-------------+---------------------------+
*  40
*
*** Overlay for XLDRFLGS in MODHDCB

MODHDCB Cross Reference

Symbol         Dspl Value
-------------- ---- -----
AMODEANY       002C C0
AMODE24        002C 40
AMODE31        002C 80
ARCFLAG        002E
CLEANMOD       002D 10
CLEAROPT       002B 40
FIXDTRNS       002D 08
FORMAT31       002D 40
HISTSIZE       0034
ICATCH         0038
INVALXA        002E 40
INVALXC        002E 20
INVLD370       002E 80
ISAPO          002A 40
LRLDBYTS       0032
MAP24BYT       002B 02
MODALL         002B 10
MODDBLEN       0040 00000008
MODDOS         002B 20
MODEFLAG       002C
MODFLAG        002B
MODHDLEN       0040 00000040
NOERASE        0020 04
NOLOADMF       002B 80
NUCONMAP       0000
POFLAG         002A
POREC          003A
POSTXA         002B 01
RELODATA       002D 80
RESERVED       0022
RLDFLAG        002D
RLDRECS        0030
RMODEANY       002C 20
RMODE24        002C 10
RSVD0          0010
RSVD1          0024
STARTADR       0000
STRINIT        0021 80
SYSTEM         0020 01
TABLENT        0028
TWORLD         002D 20
XFRSTLOC       0004
XLASTLOC       0008
XLDRFLGS       0020
XLDRNOER       0020
XLDRSTRN       0021
XLOCCNT        000C