cgen, GNU gdb/sim, and full system simulation

[Peter Gavin]

Hello,

I'm working on a port of the gdb simulator for OpenRISC.  I was
wondering if anyone had any input on how difficult a full-system
simulator would be to implement vs. the syscall emulated simulators
the other ports seem to use.

The primary thing I'm concerned about at the moment is virtual memory.
 It doesn't look like there's an easy way to add virtual memory to the
simulators.  It would be easy enough to do for load and store
instructions, just by adding a call to an address translation function
prior to accessing the memory.  But it doesn't look like there's a way
to translate the PC prior to fetching an instruction.

I don't mind do a little hacking on the framework, but I don't want to
break things, and I'd like to get some input from you guys before I
start doing that :)

Thanks for your help,
-Pete