Re: SH5 simulator contribution

[Ben Elliston <bje@redhat.com>]

>>>>> "Andrew" == Andrew Cagney <ac131313@cygnus.com> writes:

  Andrew> That would be very useful.  This means that when you say it supports the
  Andrew> sh2..sh4 it is through the backward compatibility of the instruction set
  Andrew> architecture. This explains why the config tweeks only enable the
  Andrew> simulator when sh64-elf.

Correct.

  Andrew> If I understand the sim/sh simulator correctly, it currently generates 
  Andrew> an sh-dsp sim which is backward compatible with sh2-4 (sh1?) but not 
  Andrew> with sh5.  This means that the new sh5 simulator is not a drop in 
  Andrew> replacement for the existing simulator (it lacks sh-dsp).

Also correct.

  Andrew> Unless the new simulator gains sh-dsp support, the sim directory will 
  Andrew> need to be configurable so that the user can select either the DSP xor 
  Andrew> the SH5 simulator.  That, I suspect, is going to get messy.  I think GDB 
  Andrew> should be able to assume a single SH remote-sim interface but here, I 
  Andrew> suspect, it is currently contending with two different interfaces :-(

Hence, this is why the sh5 sim is only configured when the target is
sh64-*-elf.

Ben