$MSGBK

Prolog  

Control Block Contents  
   $MSGBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

$MSGBK Prolog

 NAME       : LGRMSGBK
 DESCRIPTION: Relocation mapping for HCPMSGBK
 DSECT      : $MSGBK
 FUNCTION   : LGRMSGBK describes those fields of the MSGBK that
              will be migrated to the destination system during
              guest relocation.
 LOCATED BY : This is a mapping of the RDODATA area within the
              RDOBK during guest relocation.
 RELOCATION CONSIDERATIONS : This control block is used during live guest
              relocation.  It is used to relocate a control block
              defined in a corresponding HCP COPY file.  Any
              fields or bits defined in HCPMSGBK which are
              required on the destination system must be defined
              here, and code must be added to migrate the field
              or bit during a relocation.

$MSGBK Control Block Content

$MSGBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      $MSGBK         Relocation mapping for HCPMSGBK
          00000001       $MSG_VER       1 Mapping version number
0000    0 Signed       2 $MSG_HDRL      Header length (in bytes)
0002    2 Signed       2 $MSG_BITL      Length of mapped bits (in bytes)
0004    4 Signed       4 *              Reserved for future use
          00000008       $MSG_HDLN      *-$MSGBK Length of header (bytes)
      Bit map: Contains the MSGBK flags that are subject to
               relocation. These bits are defined sequentially,
               regardless of how they are defined in HCPMSGBK.
               This yields a consistent mapping that ensures
               compatibility when a guest is relocated between
               systems at differing service levels.
               Names in the comments column indicate the control
               block byte which contains the flag. This name is
               subject to change if the flag definition changes.
         ====> NEVER change bits which already exist here.
         ====> NEVER change the order of bits in this section.
         ====> ALWAYS add new bits at the end of this section,
               together with new flag bytes as required.
0008    8 Signed       2 $MSG_BITS (0)  Bit map area
          00000000       $MSG_BLEN      *-$MSG_BITS Length of bit map
                                        area
      Data:    Contains all HCPMSGBK data that is subject to
               relocation, except for flag bits, which are
               handled separately.
               All fields are defined as XLnn to avoid alignment
               warnings and to pack the data efficiently.
         ====> NEVER change fields which already exist here.
         ====> NEVER change the order of fields in this section.
         ====> ALWAYS add new fields at the end of this section.
               together with new flag bytes as required.
0008    8 Bitstring    1 $MSG_DATA (0)  Start of data map
0008    8 Bitstring    4 $MSGFPNT       -> RDO offset to next $MSGBK
000C   12 Bitstring    4 $MSGTGCLS      TARGET MESSAGE CLASS
0010   16 Bitstring    4 $MSGSNDAD      -> RDO offset to message data
0014   20 Bitstring    4 $MSGSNDLN      SEND BUFFER LENGTH
          00000018       $MSG_LEN       *-$MSGBK Total length, in bytes
          00000003       $MSG_SZ        ($MSG_LEN+7)/8 Size in
                                        doublewords

$MSGBK Storage Layout

          
*** $MSGBK - Relocation mapping for HCPMSGBK
*
*     +-------------+-------------+---------------------------+
*   0 | $MSG_HDRL   | $MSG_BITL   |///////////////////////////|
*     +-------------+-------------+---------------------------+
*   8 |         $MSGFPNT          |        $MSGTGCLS          |
*     +---------------------------+---------------------------+
*  10 |        $MSGSNDAD          |        $MSGSNDLN          |
*     +---------------------------+---------------------------+
*  18
*
*** $MSGBK - Relocation mapping for HCPMSGBK

$MSGBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
$MSG_BITL      0002
$MSG_BITS      0008
$MSG_BLEN      0008 00000000
$MSG_DATA      0008
$MSG_HDLN      0004 00000008
$MSG_HDRL      0000
$MSG_LEN       0014 00000018
$MSG_SZ        0014 00000003
$MSG_VER       0000 00000001
$MSGFPNT       0008
$MSGSNDAD      0010
$MSGSNDLN      0014
$MSGTGCLS      000C