Technical data
System Dump Analyzer
READ
Table SDA–13 (Cont.) Modules Defining Global Locations Within the Executive
Image
File Contents
TCPIP$NFS_SERVICES.STB
1
Symbols for the TCP/IP NFS server
TCPIP$PROXY_SERVICES.STB
1
Symbols for the TCP/IP proxy execlet
TCPIP$PWIPACP.STB
1
TCP/IP PWIP ACP
TCPIP$PWIPDRIVER.STB
1
TCP/IP PWIP driver
TCPIP$TNDRIVER.STB
1
TCP/IP TELNET/RLOGIN server driver
WORKING_SET_
MANAGEMENT.EXE
Swapper, its supporting routines,
and working set management system
services
1
Only available if TCP/IP has been installed. These are found in SYS$SYSTEM, so that all files are
not automatically read in when you issue a READ/EXEC command.
Examples
1.
SDA> READ SYS$SYSTEM:SYSDEF.STB
%SDA-I-READSYM, reading symbol table SYS$COMMON:[SYSEXE]SYSDEF.STB;1
The READ command causes SDA to add all the global symbols in
SYS$SYSTEM:SYSDEF.STB to the SDA symbol table. Such symbols are
useful when you are formatting an I/O data structure, such as a unit control
block or an I/O request packet.
2.
SDA> EXAM/INST EXE$QIO+2;4
EXE$QIO+00002: CHMK #001F
EXE$QIO+00006: RET
SDA> EXAM/INST V_EXE$QIO
%SDA-E-BADSYM, unknown symbol "V_EXE$QIO"
SDA> READ/RELOCATE=IO_ROUTINES SYS$LOADABLE_IMAGES:IO_ROUTINES.EXE
%SDA-I-READSYM, reading symbol table SYS$COMMON:[SYS$LDR]IO_ROUTINES.EXE;1
SDA> EXAM/INST EXE$QIO+2;4
EXE$QIO+00002: MOVZBL 04(AP),R3
EXE$QIO+00006: CMPB R3,#3F
SDA> EXAM/INST V_EXE$QIO+2;4
V_EXE$QIO+00002: CHMK #001F
V_EXE$QIO+00006: RET
This SDA session shows that the initial examination of the instructions at
EXE$QIO+2 and EXE$QIO+6 produces the vector for the system service,
not the system service code itself. The subsequent READ instruction brings
into the SDA symbol table the global symbols defined for the system’s I/O
routines, including one that redefines the entry point of the system service
to be the start of the routine EXE$QIO. Thus, the second examination of the
same memory locations produces the first two instructions in the routine. The
READ command creates a special symbol, V_EXE$QIO, that points to the
system service vector.
SDA–65