On Wed, 23 Mar 2011, Herbert Poetzl wrote: > > Greetings! > > I'm trying to evaluate my options on debugging a recent > laptop/notebook/table (and the Linux kernel on it of course) > from early bootup to diagnostics when the machine has locked > up ... > > normally the first thing I would do is to attach a serial > console to monitor the early bootup and have some way to > send sysrq triggers ... but here is the first problem, > the thing might not even have a serial port at all ... > > most modern devices have at least one usb port, but as far > as I could figure out via google, there is no support for > console or similar over usb (serial or not) atm > (please feel free to correct me here :) There _is_ support for a USB console (see CONFIG_USB_SERIAL_CONSOLE). However it may not be useful for diagnosing problems during boot, because obviously the console won't operate until the USB stack is in place and running. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html