[U-Boot-Users] Device chaining, anyone interested?

Detlev Zundel dzu at denx.de
Thu Aug 21 17:36:40 CEST 2003

Hello Richard,

> I looked at the POST code and it seemed "so" PPC centric that I was thinking
> it would be faster to make a parallel type directory.  I had written a bunch
> of tests for another compiler/loader and am starting to port them over.
> Actually, I was considering using the new "standalone" code model as a way
> to call the tests.  This way they could be more decoupled from the actually
> u-boot code itself.

Yes, the POST code _is_ PPC centric due to the customer who wanted
it.  It would _still_ be nice to make an effort and integrate new CPUs
into this framework pointing out the weaknesses in the current
framework so it will be easier to merge in more arch specific stuff
later on.

It seems like a waste to me to write e.g. RAM tests for every arch
when the code _already_ in the POST is a very thorough test which
should be usable by other architectures as well.  I am sure that if
the POST framework was made ready for other architectures, everyone
will win in the end.

Note that there is already the concept of "slow" and "fast" POST tests
meant for daily usage aiming at fast boot speeds and trouble-shooting
usage for thorough testing of the hardware.  Concepts like this are
sure to crop up for every CPU so why not solve them in a common way?

> The device chaining seems to be working for us, it pretty much
> implements a list of devices which are called in order with heads
> being stdin/out/error.  The person who did the work this week did
> seem to indicate that the deregister stuff that was there wasn't
> done very well.

I guess this is because there are no real users of the de-registering
code.  To borrow an often read statement from Wolfgang:

FFTSAP (Feel Free To Submit A Patch) ;)


You live and learn

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