[coreboot] USB debug cables and emulation

[Ken.Fuchs at bench.com]

> Joseph Smith wrote:
> >> The blog entry explicitly states that it didn't work.
> >>
> >>     
> > Than you did not read all of it. At the end"I was finally 
> > able to get
> > console output on the iMac"

Stefan Reinauer wrote:
   
> With the downside that you need a full blown USB stack around 
> for that.

What about something less than a full USB stack similar to Porus?

http://porus.berlios.de/

> So it starts working some time after a kernel is running. I am sure 
> that's pretty good for what it does, but it does not replace 
> the DC20, unfortunately

Of course a JTAG device might be better.  On the other hand,
a NET20DC ($83) is a real bargain compared to an American Arium
ECM-50 or for XDP JTAG, the ECM-XDP3.

http://www.coreboot.org/JTAG/BSDL_Guide probably should be updated.

The Intel and Arium links at the bottom of this page are
no longer valid.

Here's a Geode JTAG tool that may be useful to list on coreboot's
JTAG/BSDL Guide:

http://www.fs2.com/geodetools.html

http://www.fs2.com/pdfs/SNAV-GX.pdf

Back to USB Debug Port:

Here's an old USB Debug Port presentation that may be useful to
those new to the concept:

http://www.usb.org/developers/presentations/pres0602/john_keys.pdf

Is the NET20DC really the only USB Debug Device available?  I tried
searching for others, but didn't find any.

Sincerely,

Ken Fuchs

P.S. Stefan, are you having e-mail filter problems?