RE: [ECOS] Creating eCos flash application image for AT91 EB40aRedboot

[Øyvind Harboe <oyvind dot harboe at zylin dot com>]

> Indeed, it is this way by design.  IMO loading stuff into 
> memory is quite distinct from writing to the FLASH.  There 
> are times when one wants to do one and not the other and I 
> don't think that the functions should be intertwined like this.  
> Then there is the problem 
> of reasonable ways to manage the two functions.  Some devices 
> may take a very long time to write - how might one throttle 
> the incoming data stream while this happens?  That's just one 
> of many complications that would be added if these functions 
> were combined.  Another thing is that it's a good idea to 
> verify that the image has been correctly downloaded before 
> committing to FLASH - that's why there's a separate checksum 
> command.  This is just part of the list...

These are good explanations why it isn't technically straightforward
to implement a pervasive robust serial->flash programming option
to the Redboot load command.

>From a product point of view it is nice, as we have been able
to in the past, to launch any terminal program, type in
a single command, upload a single file and reset the
unit. Poof done! 

This avoids dependency on a custom app to do all these steps
for the user. With 64k chunks and 2MB flash, it can't be done
manually. 

Currently I believe the best option is to write a custom upload
app and leave Redboot be. We use Java on the desktop side of
things, so supporting a couple of platforms is doable.

Once my eCos superpowers reach their prime, I may attempt to
add a robust "load directly to flash" option to Redboot. :-)

Øyvind




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