IOBLOK IOBLOK contains information required to perform I/O operations. The I/O request
initiator fer the I/O operation is either a CF-initiated or virtual machine-initiated
event. There are five pointers to the IOBLOK: RCHFICB field of the BCHELOK, RCHFIOE field of the RCUBLOK, RDEVAIOB field of the Rt!VBLOK, VDEVFIOB field cf the VDEVBLOK, RDEVFIOB field of the RDEVBLOK. 0 8 10 18 20 28 30 38
Hexadecimal
Displacement
------------ 0 2
3
r
IOBRADD 11* 1 11*2 IOBLINK IOBFPNT IOEEPNT IOBCYL IOBVADD IOBMI5C IOBUSER IOBIRI IOBCAW IOERCIW IOBCSW IOBIOER IOBMI5C2 1*3 1*4
Field Name IOBRADD DS lOB FLAG DS Bit§ IOBCP EQO IOBRSTRT EQO IOBSPLT EQO IOBPAG EQO IOBRELCU EQU IOBERP EQO IOBRES EQO IOBBVC EQO IOBSTAT DS IOBFATAL EQU IOBFLT EQU IOBPATBF EQU lOB MINI EQO IOBALTSK EQU IOBCC3 EQU 1OBCC2 EQU IOBCC1 EQO IOBCCO EQO 1//IOBRSV2//I//////////1OBR5V3//////////// 1B 1X in IOBFLAG -X'8o.- X'40' X'20' X'10' X'08
i X'04' X'02' X'01' 1X in IOBSTAT --X'80-'-- X'40' X'20' X'08' X'04' X'03' X'02' X'01' X'OO' Field Description, Contents, Meaning Real device address for SIC 1*1 IOBLCK flags CP-generated I/O operation
Restarted oFeration - IOBRCAW DISC - CP split seek operation IOBLCK created for paging I/O Control unit released at initiation I/O task is under control cf ERP I/O task has been reset I/O initiated via DIAGNOSE instruction 1*2 IOBLCK status Unrecoverable error in this I/O operaticn IOELOK queued pending completion of a MSS cylinder fault Path is fixed, use IOBRADD value
This is a mini-IOBLOK DASt channel program has seek tc alternate
track
processing CC 3, not available
processing CC 2, channel busy
processing CC 1, csw stored
processing I/O interrupt
Section 1. CP Data Areas and Centrel Blocks 25

IOBLOK Hexadecimal
Displacement
------------
4
8 C 10 12
14
18 1C 20 24
28 30 34
38
39
31 3C 12
Field Name IOBLINK DS IOBFPNT DS IOEBPNT DS IOBMSIZE EOO IOBCYL DS IOBVADD DS IOBMISC DS IOBOSER DS IOBIRA DS IOBCli DS IOBRCAi DS IOBCSi DS IOBIOER DS IOBMISC2 DS lOB SPEC DS Bit§ IOBTIO EOO IOBBIO EQO IOBSIOF EQO IOBIMSTK EQO IOBONSL EOO IOBCOPY EQO IOBSENS EQO IOBTRPND EOO 1F
1F
1F (*-IOBLOK) /8
1H
1H
1F
1F
1F
1F
1F
1D
1F
1F 1X in IOBSPEC --X'80-' - X'40' X'20' X'10' X'08' X'04' X'02' X'01' 1*3 Field Description, Contents, Meaning Pointer for multipath IOELCK chain
Pointer to next IOBLOK in queue
Pointer to previous IOBLOK in queue
Multiple path IOBLOK size in dcublewcrds (X'02') DASt - seek cylinder for tbis ICELOK Virtual device address Ose varies according to caller
Pointer to VMBLCK of user IOELCK interrupt return address
Pointer to CCIl chain
Pointer to restart CCIl chain
Real CSIl for I/O operation
Pointer to IOERBLOK with sense byte Ose varies according to caller IOELCK special requests flag IOELCK request for a TIO IOBLCK request for a HIO Virtual SIO fast release Shut down StR function IOELCK resulting fro. unsolicited interrupt I/O block associated with a COpy request Sense operation for COpy request Virtual trace pending on tbis I/O block IOBSPBC2 DS 1X I-*4 IOB-LOK spe-cial req-uests flag-secoDdbyte in IOESPEC2 IOBiRIP EQO --X '80-' -- IOBCLN EOO X'40' IOBONREL EQO X'20' IOBOC EQO X'10' IOBSNSIO EOO X'08' IOBREL EQO X'04' IOBRSV2 DS 1B IOBRSV3 DS 1F IOBSIZE EOO (*-IOBLOK)/8 1.Q£ fE IOBLOK§ ORG IOBVADD IOBRCNT DS 1H
Input/output task for AOTOPCLL wrap list VDEVELOK locked when CCIl gct control
Input/output task contains release, DMKONT must process Onit check status
Nor.al sense operation in Frogress Channel program contains CP release
Reserved for IBM use
Reserved for IBM use IOELOK size in doublewords (X'OS') Retry count
26 IBM VM/370 Data Areas and Control Block Logic