Re: SID and eCos

[Ben Elliston <bje@redhat.com>]

Hi Scott,

>>>>> "Scott" == Scott Dattalo <scott@dattalo.com> writes:

  Scott> The Makefile I used to create the executable is part of eCos. I 
  Scott> specifically target Atmel's AT91EB40 evaluation board. The generic, out of 
  Scott> the box, SID arm emulation knows nothing about an AT91EB40. The error 
  Scott> reported above is telling me that the executable accesses RAM that doesn't 
  Scott> exist (hey, I think I like that:).  So I added a few --memory-region's:

  Scott> $ arm-elf-sid --cpu=arm --memory-region=0x2020000,0x20000 
  Scott> --memory-region=0xfffe0000,0x1ffff --gdb=2000 -EL hello

  Scott> And that worked! 

You're right.  The problem is that the default ARM configuration does
not include as expansive memory regions as the GDB simulator, so your
program was writing into unmapped regions.

  Scott> So now it looks like I have not one, but two (mostly) independent ways to 
  Scott> simulate my source. I like the SID approach because of the added 
  Scott> flexibility; specifically the ability to profile.

Great!  I'm pleased that you've seen SID for what it is.

  Scott> sid appears to be an extraordinarily powerful tool. Is there any reason 
  Scott> why it's not more popular? Judgeing from the mailing list archives, it 
  Scott> appears that not too many people are using it.

I believe there are at least a couple of factors:

  * it has only been out on the net for a year or so; and
  * I don't think it is very widely known about.

  Scott> investigate to what extent it's possible to leverage our two projects.
  Scott> Specifically, I'd like to incorporate the abstract hardware interface that
  Scott> sid supports with gpsim.  And to reciprocate, I can add some of gpsim's
  Scott> modules to sid!

That'd be terrific!  Can you summarise what gpsim modules you have?

Regards, Ben