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

Woodruff, Richard r-woodruff2 at ti.com
Thu Aug 21 17:11:07 CEST 2003

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.

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.


Richard W.

-----Original Message-----
From: Detlev Zundel [mailto:dzu at denx.de] 
Sent: Thursday, August 21, 2003 10:02 AM
To: Woodruff, Richard
Cc: u-boot-users at lists.sourceforge.net
Subject: Re: [U-Boot-Users] Device chaining, anyone interested?

Hello Richard,

> We are in the process of putting together some POST/diagnostic type
> code for our OMAP u-boot board. 

If you are doing work on POST stuff, I hope that you are aware of the
POST framework which is used only on the PowerPC branch right now.
It'll be great if any effort in this direction could be merged under
this framework.

> We have modified the device lists for input/output such that it will
> chain to several devices.... ex: can input data at a serial keyboard
> OR at the keypad OR at the touchscreen and it will output to the
> serial console AND the LCD console (and potentially a USB-client
> serial console).  This is all very handy for what we are doing, but
> I'm not sure if its something which the generic u-boot code wants
> (Wolfgang?).  Its been put together with the standard list functions
> and such so its not a great departure in code.

I cannot speak for Wolfgang, who is on holidays by the way, but in my
opinion it is a worthwhile effort.  What comes to my mind immediately
is to chain some output device the user can see and the logbuffer
device which is available under Linux after the kernel has taken
control.  So please go ahead and post the patches here.


Emacs is the way to purify your soul using garbage collection.

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