On Tue, Jul 14, 2009 at 08:38:15 -0700, ron minnich wrote:
I like it. We talked about something like this in v3. How would you feel about putting in emergency flash upgrade support :-)
I like the flash upgrade idea, but I'm not sure how to do it yet (in a generic way). Any suggestions?
I think it might be possible without any changes by marking the part of the ROM containing xcshell as cacheable, and then using pokes to rewrite the rest of the chip. It would be slow, but a small flash upgrade program could be uploaded that would do the rest of the work more quickly.
My original idea was that one would set up CAR, upload code, and jump to it; this would allow the system to be extended without having to include much code. It doesn't work, at least on my Pentium 3, but the same thing could be done with RAM once it's initialised (or with flash for occasional use).
-- Michael