BPLBK

Prolog  

Control Block Contents  
   BPLBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

BPLBK Prolog

 NAME       : HCPBPLBK
 DESCRIPTION: *BLOCKIO parameter list dsect
 DSECT      : BPLBK
 FUNCTION   : This DSECT maps the input parameter list sent
              by the guest to CP when the guest requests a
              multiple block I/O operation from *BLOCKIO
 LOCATED BY : SNDPLADR in SNDBK
 CREATED BY : HCPBIMMS (who copies the guest's parameter
              list into host storage)
 DELETED BY : HCPBIMMS
 SERIALIZED : Unique task execution
              VMDBK dispatch lock.
              BLOCKIO lock
 Notes      : When the guest sends the address in guest storage
              of this parameter list, it may not be word-aligned.
              This DSECT assumes that before any fields are
              referenced, the parameter list has been moved into
              host storage and been word-aligned.  References
              to address fields will cause an exception if this
              is not the case.

BPLBK Control Block Content

BPLBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BPLBK          *BLOCKIO parameter list dsect
0000    0 Signed       4 * (0)
0000    0 Bitstring    1 BPLRQCOD       Request code
          00000001       BPLWRITE       X'01' Write request
          00000002       BPLREAD        X'02' Read request
0001    1 Bitstring    1 BPLRETCD       Return code for this operation
0002    2 Bitstring    2 *              Reserved for IBM use
0004    4 Address      4 BPLBUFAD       Guest real address of data buffer
0008    8 Signed       4 BPLBKNUM       Block number. Signed value; may
                                        be negative.
000C   12 Signed       4 *              Reserved for IBM use
0010   16 Signed       4 BPLNXENT (0)   Next entry in p-list starts here
          00000002       BPLSIZE        (*-BPLBK+7)/8 Size, in
                                        doublewords, of BPLBK

BPLBK Storage Layout

          
*** BPLBK - *BLOCKIO parameter list dsect
*
*     +------+------+-------------+---------------------------+
*   0 |:RQCOD|:RETCD|/////////////|         BPLBUFAD          |
*     +------+------+-------------+---------------------------+
*   8 |         BPLBKNUM          |///////////////////////////|
*     +---------------------------+---------------------------+
*
*** BPLBK - *BLOCKIO parameter list dsect

BPLBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
BPLBKNUM       0008
BPLBUFAD       0004
BPLNXENT       0010
BPLREAD        0000 00000002
BPLRETCD       0001
BPLRQCOD       0000
BPLSIZE        0010 00000002
BPLWRITE       0000 00000001