[ECOS] eb40a application boot

[Shannon Holland]

OK, I'm now back after a lovely (but not long enough) vacation. Just 
before I left I got redboot working nicely on my ramless (external) 
eb40a board. I believe others were interested in knowing what I did. Is 
that still true? If so I can post details of what I did to get there.

Next step is getting an ecos based app running. I've configured an ecos 
kernel for eb40a and build the hello.c application. I can download it to 
the board via redboot/hyperterm or through gdb, but when I run it, no go.

Using gdb and single stepping into it, it's writing over the exception 
vectors at address 0, after writing over the wrong ones, gdb dies - 
surprise surprise! Not sure if the app itself keeps running or not.

I thought I had it configured so that it would use redboot as the ROM 
monitor and not overwrite the vectors, but after poking through the 
vectors.s boot code, it appears to always overwrite at least some of 
them. Is this correct?

If I push the pc past some of the offending instructions I can keep 
going, only to later die in the hal initialization.

Are there some common gotcha's I'm hitting or might anyone have any 
recomendations as to what I should look into? Which vectors should the 
app be overwriting and which should redboot be holding onto?

Thanks for any info! I can also post more detailed info as to what I've 
done here - it's probably something really stupid!

Shannon


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