User manual

VAX MP SIMH console extensions
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memory script with the following content (assuming, by the way of example, that processors 3
and 4 triggered breakpoints and console’s previous default context was CPU0):
CPU ID 3
… breakpoint action commands triggered by CPU3 …
CPU ID 4
… breakpoint action commands triggered by CPU4 …
CPU ID 0
Console thread then executes this script. If any of the invoked actions contained CONT(INUE), it
will not be executed immediately, but recorded as a flag till all other commands specified in the
actions complete. If “continue” flag is set after the execution of the script, console thread will
execute CONT(INUE) after the whole script had been performed.
STEP, on the other hand, is executed immediately, in-sequence with respect to other breakpoint
action commands. This allows to define breakpoint handling scripts that examine the state,
execute STEP on the paused processor and examine the state again after the step.
If execution of STEP triggers another breakpoint, console thread will build another script and
execute it as a nested script. There can be a stack of nested scripts for breakpoint invocations.
As a safety measure against runaway scripts, script nesting depth is limited.
Commands RUN, GO and BOOT cannot be executed directly or indirectly (in the invoked script
files) from a breakpoint action context. Attempt to execute them will be rejected with diagnostic
message.
If breakpoint action invokes STEP command, it will be executed for the processor that triggered
the breakpoint. If multiple processors triggered breakpoints with STEP in the bound actions,
STEP will be executed for all of them.
If breakpoint action invokes CONT(INUE), this command will be executed after all other
commands listed in all triggered actions complete.
WS_LOCK, WS_MIN, WS_MAX
Significant paging of simulator’s code or data
1
during multiprocessor execution may negatively
affect performance of the system. If VCPU thread experiences page fault while holding a
resource lock, other VCPU threads may have to wait till page fault is resolved. It is therefore
1
Including simulator’s own code and data, code and data of runtime libraries used by the simulator and host
memory region that holds VAX “physical” memory.