SVCSECT SVCSECT describes the fields used by DMSITS in handling SVC interrupts. An SVCSECT block
is built dynamically when an SVC is issued. 1he first SVCSECT is pointed to by the ASVCSECT field in NUCON; if SVCs are nested, the chain of SVCSECT blocks is processed
using the CURRALOC and LASTALOC fields.
o JNUMB JFIRST
8 JF4 JLAST 10 A*1 1//////1 SVCAB CURRALOC 18 LASTALOC DEPTH 20 ADMSOVS OVEPF OVBTF 28 OVAPF OVATF A*2 1//////////////////// 30 SVCSAVE 18 NRftSAV 158 ///////////////////////////1 SVCOUNT 160 SVCSTOP SVLAD 168 SVLADW SVLFS 110 LOADLIST 118 LOADNAftE 180 (Literals are loaded into this area)
188 (The literals here are from the origin) 190 LOADSTRT
198 (Hexadecimals are entered in this area) 1AO ///////////////////////////1/////1///11////////////////
1A8 ftODLIST 1 BO DUftCOft 1B8 A*3 ZER03 TRANSRT 1CO TRANSRT (cont.) A*4 AtTRINS 1C8 TEftP02 1DO /////////////////1/////////1//1//////////1/////////////
1-----------------------------------------------------
1D8 1///////////////////////////1//1///1///1/1///1//1/////// I I 1 EO I RGPRO RGPR 1 I , 234 IBM VM/310 Data Areas and Control Block Logic

1E8 RGPR2 1FO RGPR4
1F8 RGPR6 200 RGPR8 208 RGPR10 210 RGPR12
218 RGPR14 220 228 230 238 240 Hexadecimal Field
Displacement Name o o 4
8
C
11
12
14
18
1C 20 24
26
28
2A USVCTBL DS JFIRST JF4 JLAST DC
DC
DC Bit§ SFSYS EQU SFTRN EQU SFNue EQU SFREN EQU DC SVCAB DC CURRALOC DC LASTALOC DC
DEPTH DC ID!!SOVS DC OVBPP DC OVBTP DC OVAPP DC OVATP DC OF ! (*-*)
F'4'
A (*-*)
in SFLAG --X'80'- X'40' X'20' X'01' X'OO' H'O' A (0) A (0) P'O' for SVCTRACE --A(O)"----- BL2 n on
BL2"on
BL2"on BL2
n
O" SVCSECT RGPR3
RGPR5
RGPR7
RGPR9
RGPR11
RGPR13
RGPR15 RFPRO RFPR2
RFPR4
RFPR6 NR!!USAV Field Description# Contents, !eaninq User SVC tatle No. of douhlewords 1D SVC number table Address of first item (if any] in table
Loop increment for BXLE Address of last item in table Systell flag -- SVC protect key is zero
Transient area routine -- system mask is
Nucleus routine -- system .ask is off
Invalid reentry flag
Reserved for IBft use SVC abend code if any
Current allocated save area
Last allocated save area
Nested SVC depth
Address of I!!SOVS nBefore print" flags
nBefore type" flags
nAfter print" flags
nAfter type
n
flags
off Section 2. CftS Iata Areas and Control Blocks 235