Re: Console on USB

["Randy.Dunlap" <rddunlap@osdl.org>]

>>   So I ordered a USB to serial converter, configured a 2.6.0-test3
>> kernel, added a console=/dev/ttyUSB0 to the kernel command line and
>> connected this to my desktop with a null modem adapter.
>
> What made you think this will work?!

Maybe the drivers/usb/serial/Kconfig file?

config USB_SERIAL_CONSOLE
        bool "USB Serial Console device support (EXPERIMENTAL)"
        depends on USB_SERIAL=y && EXPERIMENTAL

>> Is there any advice I might be able to use to get this going?
>
> You'd have to write it. Grep for register_console for starters.
> But I do not advise it, see below.

usb/serial/console.c:255:         register_console(&usbcons);

>>  I really want to be able to catch some oops output.
>
> If oops happens with interrupts closed, forget about it.
> USB needs interrupts to work. This is one of the reasons nobody
> bothered to implement console over USB serial.

The call to register_console() also happens very late in the boot
sequence, so if your oops is early, USB console won't help.

> You will have a better chance using Ingo's netconsole, if a patch
> for your Ethernet driver exists.

Certainly, I agree.

~Randy