MLDBK | Back to Index page

| Prolog Control Block Contents MLDBK DSECT MLDENTRY DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

MLDBK Prolog | Top of page

     NAME       : HCPMLDBK
     DESCRIPTION: Mapping List Definition Block.
     DSECT      : MLDBK
     FUNCTION   : The MLDBK is used to pass parameter for
                  diagnose X'244'.
     LOCATED BY : MPLMLDBK - contains the address of this block.
     CREATED BY : Created in the guest virtual machine's storage and
                  copied to VMDVOBUF for CP to use.
     DELETED BY : Deleted by the guest virtual machine.
     SERIALIZED : Guest Virtual Machine is responsible.
     RELOCATION CONSIDERATIONS : None
     COMMENTS   : NONE

MLDBK Control Block Content | Top of page

     MLDBK DSECT
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    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      MLDBK          Mapping List Definition Block.
    0000    0 Signed       4 MLDALET        ALET specifying the ad- dress
                                            space in which the next MLDBK
                                            resides.
    0004    4 Signed       4 MLDFWDPT       Forward pointer to next MLDBK.
    0008    8 Signed       4 MLDENTCT       Count of entries contained in
                                            this block.
    000C   12 Signed       4 *              Reserved for IBM use.
    0010   16 Signed       4 MLDENTR1 (0)   First entry in variable list.
                                            This is a pool-
                                            relative-block-number
                 The following are used to determine the size of the
          header for this control block.                            .
              00000010       MLDLEN         *-MLDBK Length of this control
                                            block in bytes.
              00000002       MLDSIZE        (MLDLEN+7)/8 Size of this control
                                            block in doublewords.
                 The following DSECT fields are for the variable data.

     MLDENTRY DSECT
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    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      MLDENTRY       Mapping List Definition Block.
    0000    0 Signed       4 MLDPRBN        An entry that is a pool-
                                            relative-block number.
              00000004       MLDETLEN       *-MLDENTRY Length of the 1st
                                            entry.
    0004    4 Signed       4 MLDNXTET (0)   Next extent in list.
              00000400       MLDNMETP       4096/MLDETLEN The number of
                                            entries contained in a page.
                                            ****************-------
              00001000       MLDSZETP       MLDETLEN*MLDNMETP Total storage
                                            size of all entries that can fit
                                            into a page.

MLDBK Storage Layout | Top of page

    *** MLDBK - Mapping List Definition Block.
    *
    *     +---------------------------+---------------------------+
    *   0 |         MLDALET           |         MLDFWDPT          |
    *     +---------------------------+---------------------------+
    *   8 |         MLDENTCT          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *
    *** MLDBK - Mapping List Definition Block.

    *** MLDENTRY - Mapping List Definition Block.
    *
    *     +---------------------------+
    *   0 |         MLDPRBN           |
    *     +---------------------------+
    *
    *** MLDENTRY - Mapping List Definition Block.

MLDBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    MLDALET        0000
    MLDENTCT       0008
    MLDENTR1       0010
    MLDETLEN       0000 00000004
    MLDFWDPT       0004
    MLDLEN         0010 00000010
    MLDNMETP       0004 00000400
    MLDNXTET       0004
    MLDPRBN        0000
    MLDSIZE        0010 00000002
    MLDSZETP       0004 00001000

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:29:12 EDT.
Copyright IBM Corporation, 1990, 2020