I have posted two coded fragments from a program I found on the Internet.
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* 00009700
L R3,0(,R1) PARAMETER POINTER 00009800
LA R3,0(,R3) ZERO BIT 31 00009900
* 00010000
MODESET MODE=SUP 00010100
IPK , Get PSW Key in R2 00010200
LR R11,R2 SAVE PSWKEY 00010300
SPKA X'70' Switch To PSW Key 7 From address 00010400
* 00010500
STORAGE OBTAIN, OBTAIN WORKAREA X00010600
LENGTH=WORKLEN, X00010700
CALLRKY=YES, X00010800
LOC=BELOW, X00010900
SP=129 00011000
MVC 4(4,R1),=CL4'F1SA' INDICATE LINKAGE STACK USED 00011100
LR R13,R1 00011200
USING WORKAREA,R13 00011300
* 00011600
SPKA 0(R11) Switch Back To Original PSW Key 00011700
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In the Above snipet of code A Storage Obtain is issued for Subpool 129 with
the CALLRKY=YES. It is my understanding that PSW Key had been previously set
to Key 7 by the SPKA instruction.
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DLM8 DS 0H 00013800
SPKA X'70' Switch Into Key 7 00013900
XC EPNAME,EPNAME 00014000
LR R0,R4 COPY LENGTH TO R0 00014100
LR R1,R11 COPY SOURCE KEY TO R1 00014200
MVCSK EPNAME,2(R3) COPY EPNAME 00014300
OC EPNAME,=CL8' ' FORCE UPPERCASE AND BLANKS 00014400
SPKA 0(R11) Switch Back To Original PSW Key 00014500
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In a second code fragment (Above) the author again sets the PSW Key to Key 7,
then prepares to issue an MVCSK instruction to move some data from R3 to the
storage Obtained in the first code fragment.
I am assuming the "MVCSK" instruction is the proper method for moving data
between
two different keys, when Not in Key 0.
Register 3 contained the address of the MVS PARMS data from the EXEC DD
Statement.
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* 00037100
WORKAREA DSECT , KEY 7 WORKAREA 00037200
SAVEAREA DS 18F 00037300
STECB DS 1F ECB ADDRESS FOR ATTACH 00037400
STTCB DS 1F TCB ADDRESS RETURNED BY ATTACH 00037500
EPNAME DS CL8 EPNAME FOR ATTACH EPLOC= 00037600
LATT DS XL(LATTL) ATTACH WORK AREA 00037700
RACROUTE DS XL(MFLROUTL) WORKAREA FOR RACROUTE 00037800
SAFWK DS XL512 WORKAREA FOR SAF 00037900
WORKLEN EQU *-WORKAREA 00038000
* 00038100
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So Why is it necessary to use MVCSK instruction in the second code fragment and
its not necessary in the first code fragment ?
Paul D'Angelo
