[LinuxBIOS] USB Support

Stefan Reinauer stepan at coresystems.de
Fri Jul 7 20:10:52 CEST 2006

* Peter Stuge <stuge-linuxbios at cdy.org> [060707 19:52]:
> This is a nice idea.
> On Fri, Jul 07, 2006 at 04:18:25PM +0200, Stefan Reinauer wrote:
> > > what you need is a debug device, which mostly looks like a usb
> > > style null modem cable. No idea where to get this hardware
> > > though.
> > 
> > D'uh - it reads any usb 2 to usb 2 data link cable can be used for
> > this purpose. Such cables are available for ~ 10$
> Where did you read this?
> I doubt they will work, unless the manufacturers were exceedingly
> clever and actually implemented the DEBUG_MODE feature in the
> device..

You are right. The cable would need to implement the DEBUG_MODE feature.

I read over page 5 of
and it actually says so.

The question is now: what devices/cables can be used for this purpose.
Or is it maybe trivial to build such a device yourself in a low
> I'm not sure if this requirement is compatible with the CDC spec that
> USB-serial adapters implement, but it would indeed be very handy if
> minicom+the kernel USB-serial driver could be used with the host end
> of the debug device.

That would indeed be great! 

> It's quite possible that the device requires a special application,
> but in any case such an application would be trivial to hack up.

Or just a small dummy serial driver so minicom or whatever could be

> I think the hard part is to find or make the hardware. Or maybe not
> so hard if you have a proven USB2 HS platform and are comfortable
> with tweaking USB descriptors. All I have handy is USB2 FS. :(
The idea is probably to get a cost effective solution, otherwise a lot
of volunteers might get locked out of joining the project.


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