Re: [RFC PATCH -next] tty: serial: add panic serial helper

From: Greg KH
Date: Wed May 17 2023 - 07:56:59 EST


On Wed, May 17, 2023 at 06:14:03PM +0800, Hongyu Xie wrote:
> It works like this:
> 1.Attach the uart side of an USB-to-UART tool to any uart port on your
> device after panic. Attach the USB side of that tool to another PC.
> Open minicom(or other app) on that PC, set /dev/ttyUSB0 with
> "115200 8N1".
>
> 2.press "Enter", you'll get something like,
>
> "
> wrong password
> Panic now, please input keyword to debug
> "
>
> 3.type "123456" and press "Enter" will prompt a help menu.
> "
> help:
> -a show all kernel msg
> -3 show S3 msg
> -4 show S4 msg
> -filter-[string] show msg contains [string]
> -q- quit
> "
>
> 4.Finally type 'a', '3', '4', 'q' or "filter-xxx" to get what you want.

All of this needs to be documented somewhere, right?

And what is this magic "123456" stuff?

thanks,

greg k-h