[U-Boot-Users] usbtty windows driver

Chris Boger cboger at gener8.net
Fri Dec 8 03:59:14 CET 2006

Hello all,

I *think* that I have properly ported the usbtty functionality to my 
XScale-based board, but I'm having some issues using it via a Windows host. 
I started off thinking that once implemented, this would be recognized by 
Windows (using the proper INF file) and use the built-in usbser.sys driver 
on my Windows XP host. But, I've been having a heck of a time getting that 
to work.

My device is enumerates and passes the USB-IF chapter 9 compliance tools 
just fine. It shows up in the Device Manager under the Ports section as a 
COM port with a yellow slash over it. After digging deeper into the code and 
the USB documentation, I see that u-boot's usbtty doesn't seem follow the 
Serial Emulation Abstract Control Model (section of the CDC spec) 
like I thought it did. In fact, USBTTY_INTERFACE_CLASS is defined as 0xFF 
(vendor specific) and not 0x02 (communication class). I also noticed that we 
don't use the interrupt IN endpoint at all.

So, am I totally wrong here or does our usbtty require a custom Windows 
device driver?

Best Regards,

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