Debug Manual

Introduction
Debug Manual—421921-003
1-9
How to Determine Process State on a Trap or Signal
Debug Header Message on page 1-10. For more information about space identifiers,
see the appropriate server description manual for the processor that you are using.
Note. You cannot resume a process that entered Debug either because it received a
nondeferrable signal or because a synchronous trap occurred. A signal is nondeferrable if it
was generated by the system because the process cannot continue executing the instruction
stream. The only traps from which you can resume are the looptimer trap and the arithmetic
overflow trap, provided that the T and V bits are not both set in the ENV register.
Resuming from any of these nonresumable situations causes the process to be terminated
with the same Guardian Stop message or OSS wait status as would have been generated had
the signal or trap terminated the process without entering Debug. For additional information
about signals and traps, refer to Guardian Programmer’s Guide.
Figure 1-1. Environment Register (TNS Environment)
Field Description Bits Values
LS Library space ENV.<4> 0 = Code space
1 = Library space
PRIV Privileged ENV.<5> 0 = Nonprivileged
1 = Privileged
DS Data space ENV.<6> 0 = User
1 = System
CS Code space ENV.<7> 0 = User
1 = System
T Trap enable ENV.<8> 0 = Disable
1 = Enable
K Carry bit ENV.<9> 1 = Carry
V Overflow ENV.<10> 0 = No overflow
1 = Overflow
N Negative or numeric condition ENV.<11> See CC
Z Zero or alphabetic ENV.<12> See CC
CC Condition code ENV.<11:12> 10 < CCL (numeric)
01 = CCE (alpha)
00 > CCG (special)
RP Register stack pointer ENV.<13:15>
1514135
PRIV
4
LS
6
DS
7
CS
8
T
9
K
10
V
12
Z
11
N
RP
CC
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