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Re: GDB-Protocol: Cycle step command?
"J.T. Conklin" wrote:
>
> >>>>> "Andrew" == Andrew Cagney <ac131313@cygnus.com> writes:
> Andrew> Hello, I'd like to propose that the GDB remote protocol be
> Andrew> extended to support a cycle step command. This command would
> Andrew> be used when either interacting with physical control devices
> Andrew> such as JTAG or (more often) cycle accurate simulators.
> Andrew>
> Andrew> Possible syntaxes include:
> Andrew> QCycle=<NR>
> Andrew> and i<NR>
> Andrew>
> Andrew> comments suggestions additional data people thing may be
> Andrew> needed. Unlike the ``S'' and ``C'' commands I've not included
> Andrew> an address. Changing the address in a cycle accurate model
> Andrew> can get very complex.
>
> This seems incomplete.
>
> If you have a command to step through processor cycles, don't you also
> need cooresponding commands to extract processor state (pipeline, tlb,
> cache, btb, etc.). Without such commands, I fail to see the value in
> being able to step in this manner.
I think that, while related, the two problems should be considered
separatly.
In the case of a cycle accurate simulator I'd expect the information you
mention to be displayed by interacting with the simulator directly
(possibly using a remote script command). Most simulators of this type
already have a command line interface.
As a separate issue (independant of cycle stepping) GDB does need to
become better at displaying processor internal state (TPB registers,
....).
enjoy,
Andrew
PS: It can't be ``QC...''.