[ECOS] eb40a application boot

[Gary D. Thomas]

On Fri, 2003-01-03 at 20:30, Shannon Holland wrote:
> 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?
> 

No, this should not be the case.

Are you sure that your application is using HAL_STARTUP_RAM mode?

> 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?
> 

The application should take over everything except illegal instruction
as that's left for breakpoints.

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

-- 
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|       Mind: Embedded Linux and eCos Development        |
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| Gary Thomas              email:  gary.thomas@mind.be   |
| Mind ( http://mind.be )  tel:    +1 (970) 229-1963     |
| gpg: http://www.chez-thomas.org/gary/gpg_key.asc       |
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