Type ASSEMBLE
Source Lines : 977
Fixes Applied : 4
Most Recent Version : Thursday, July 5, 1979
Last Fix ID : [R13122DK]
Function
PAGABLE FRAME RECORD INITIALIZATION MODULE. CALLED AT
CP INITIALIZATION TIME IF THE ERROR RECORDING CYLINDERS
HAVE BEEN FORMATTED. IF RUNNING ON A 303X PROCESSOR,
DMKIOH WILL READ FRAMES FROM ALL SRF DEVICES SPECIFIED
ON THE 'SRF=' KEYWORD OF THE RIOGEN MACRO; THE
FRAMES WILL BE FORMATTED AS RECORDS AND WRITTEN
TO THE BEGINNING OF THE VM/370 ERROR RECORDING
CYLINDERS.
DMKIOH IS ALSO CALLED DURING CPEREP 'CLEARF' PROCESSING
TO REINITIALIZE FRAME RECORDS WHEN RUNNING ON A 303X
PROCESSOR.
Attributes
PAGABLE,SERIAL-REUSABLE,CALLED BY DMKIOGF1 VIA SVC.
Operation
1. CHECK FOR ANY SRF DEVICES BY EXAMINING THE LIST
LOCATED BY DMKRIOSF. IF NONE, WRITE MESSAGE TO
OPERATOR AND RETURN TO DMKIOGF1 AT STEP 18.
CALL DMKFREE TO OBTAIN SPACE FOR AN IOBLOK
PLUS CCW'S, AND INITIALIZE THE IOBLOK.
2. PREPARE TO READ FRAMES:
- CALL DMKFREE TO OBTAIN SPACE FOR A 2K
BUFFER
- BUILD A STANDARD RECORD HEADER TO BE USED
IN CONSTRUCTING ALL FRAME RECORDS
3. CALL DMKPGTVG TO OBTAIN A VIRTUAL PAGE TO USE
IN CONSTRUCTING BLOCKED FRAME RECORDS.
4. CALL DMKRPAGT AND DMKPTRLK TO BRING THE FIRST
RECORDING PAGE INTO STORAGE AND LOCK IT THERE.
IF AN ERROR OCCURS ON THIS READ OPERATION,
DISABLE RECORDING AND RETURN TO DMKIOGF1.
5. ISSUE 'ENABLE' COMMAND TO THE FIRST SRF. IF THE
SRF IS INACCESSIBLE (OR IF IT WAS NOT SYS GEN'ED)
WRITE ERROR MESSAGE TO THE OPERATOR AND GO TO
STEP 11 TO CHECK FOR ANOTHER SRF.
6. IF THE SRF IS AVAILABLE, ISSUE A 'VERBAGE' COMMAND TO
THE SRF TO INDICATE THAT CPU FRAMES ARE TO BE READ,
FOLLOWED BY A 'RDVERB' COMMAND TO OBTAIN THE
FIRST CPU FRAME.
7. MOVE THE FRAME TO THE RECORDING PAGE AS
FOLLOWS:
- MOVE THE LENGTH OF THE FRAME RECORD
(LENGTH OF HEADER + LENGTH OF FRAME) INTO
THE 1ST FULLWORD OF THE RECORD
- MOVE THE 24-BYTE STANDARD RECORD HEADER
- MOVE THE FRAME
- UPDATE THE INDEX IN THE PAGE HEADER TO
THE NEXT AVAILABLE FREE SPACE IN THE PAGE
WHEN THE PAGE IS FULL, WRITE IT BACK TO THE
RECORDING CYLINDERS, AND READ IN THE NEXT
RECORDING PAGE TO CONTINUE THE FRAME RECORD
CONSTRUCTION.
8. CONTINUE READING FROM THE SRF UNTIL ONE OF
THE FOLLOWING OCCURS:
(A) CHANNEL END, DEVICE END, UNIT EXCEPTION
STATUS RECEIVED - END OF CPU FRAMES; GO
TO STEP 9 TO READ DIRECTOR FRAMES NOW.
(B) MORE THAN 50 CPU FRAMES READ - WRITE
ERROR MESSAGE TO OPERATOR; CONTINUE TO
FORMAT AS IF ONLY 50 FRAMES READ.
(C) ERROR STATUS (NON-CE,DE) RECEIVED FROM
RDVERB - IF ANY FRAME RECORDS ARE ON
THE RECORDING CYLS, TURN ON FRMLAST IN
LAST FRAME RECORD WRITTEN, SET DMKIOEFR
TO INDICATE FRAMES PRESENT, AND GO TO
STEP 11 TO CLEAN UP. IF NO FRAME RECORDS HAVE
BEEN WRITTEN TO THE RECORDING CYLINDERS,
GO TO STEP 11.
9. ISSUE A 'VERBAGE' COMMAND TO THE SRF TO
RETRIEVE DIRECTOR FRAMES. PROCEED AS IN STEPS
6-8, EXCEPT WHEN CE,DE,UE STATUS IS DETECTED,
GO TO STEP 10.
10. TURN ON 'LAST FRAME' FLAG IN THE LAST FRAME
RECORD WRITTEN. SET DMKIOEFR TO INDICATE FRAME
RECORDS EXIST ON THE RECORDING CYLINDERS.
11. IF THIS IS THE LAST SRF DEVICE IN THE
LIST, INDICATE THIS RECORDING PAGE
IS FULL (TO PREVENT ERROR RECORDS FROM BEING
PLACED ON THE SAME PAGE WITH FRAME RECORDS),
AND WRITE THE PAGE BACK TO THE RECORDING
CYLINDERS.
12. ISSUE A 'DISABLE' COMMAND TO DETACH FROM THE SRF.
CHECK FOR ANOTHER SRF DEVICE BY EXAMINING THE LIST
LOCATED BY DMKRIOSF. IF NO MORE SRF'S, GO TO
STEP 13. IF ANOTHER SRF IS FOUND, RETURN TO
STEP 5 TO ATTEMPT TO READ FRAMES FROM THIS SRF.
13. CALCULATE DMKIOEHS VALUE FOR USE BY CPEREP
PROCESSING. THIS FIELD IS THE DASD START OF
THE ERROR RECORDS (I.E., FIRST RECORDING PAGE
AFTER ALL FRAME RECORDS) IN CCPD FORMAT.
14. CALL DMKPGTVR TO FREE THE VIRTUAL PAGE
GOTTEN IN STEP 3.
15. CALL DMKFRET TO RELEASE THE IOBLOK, CCW'S,
AND 2K BUFFER SPACE.
16. RETURN TO DMKIOGF1 AT STEP 18.
Calls to Other Routines
DMKPGTVG - TO GET VIRTUAL PAGES.
DMKPGTVR - TO RELEASE VIRTUAL PAGES.
DMKQCNWT - TO WRITE MSGS. TO THE OPERATOR.
DMKRPAGT - TO READ A PAGE INTO CORE.
DMKRPAPT - TO WRITE A PAGE TO RECORDING CYLINDER.
DMKERMSG - TO WRITE OUT ERROR MESSAGES
DMKPTRLK - TO LOCK A PAGE.
DMKPTRUL - TO UNLOCK A PAGE.