SVC 3 – Exit

SVC 3 is a SVC entry to the exit routine. The current RB at the time the SVC 3 is issued will be terminated. If no RB’s remain for the TCB the TCB will be terminated. This SVC is entered with interrupts disabled. On entry R4 points to the current TCB and R5 points to the current RB which will be the RB created for the SVC 3 interrupt – not the RB that was active when the SVC was issued. The SVC routine needs to remove the current RB so the Exit Routine will terminate the RB that issued the SVC call.

000000                               12 S003EXIT CSECT ,
000000 18CF                          13          LR    R12,R15            ESTABLISH
                            00000    14          USING S003EXIT,R12                BASE REGISTER
                                     15 *
                            00000    16          USING @TCB,R4
                            00000    17          USING @RB,R5

000002 1825                          22          LR    R2,R5              COPY CURRENT RB ADDRESS
000004 5850 5000      00000          23          L     R5,RBNEXT          NEXT RB ON CHAIN
000008 5050 4008      00008          24          ST    R5,TCBRB           UNCHAIN CURRENT RB
                                     25 *
00000C 4110 0050      00050          26          LA    R1,RBLEN           LENGTH OF RB
000010 BF18 C030      00030          27          ICM   R1,B'1000',=AL1(128)   SP=128
000014 1802                          28          LR    R0,R2                  RB ADDRESS
000016 58F0 0014      00014          29          L     R15,20                 POINT TO MVT
00001A 58F0 F01C      0001C          30          L     R15,MVTFMAIN-@MVT(,R15)    FREEMAIN BRANCH ENTRY
00001E 05EF                          31          BALR  R14,R15
                                     32 *
000020 58F0 0014      00014          33          L     R15,20                 POINT TO MVT
000024 58F0 F024      00024          34          L     R15,MVTEXIT-@MVT(,R15) EXIT ROUTINE
000028 07FF                          35          BR    R15

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