Re: FTDI serial console support?

[Daniel Kiper]

On Wed, May 16, 2018 at 06:21:17AM +0200, Petter Gustad wrote:
> From: Daniel Kiper <address@hidden>
> Subject: Re: FTDI serial console support?
> Date: Tue, 15 May 2018 22:00:06 +0200
>
> > On Fri, May 11, 2018 at 03:55:36PM +0200, Petter Gustad wrote:
> >>
> >> Is there a way to specify a FTDI based serial console using
> >> GRUB_TERMINAL, GRUB_SERIAL_COMMAND, or some other variable? If yes,
> >> what is the syntax?
> >>
> >> BTW my serial port adapter matches the vendor id and device id given
> >> in grub-core/bus/usb/serial/ftdi.c:
> >>
> >> Bus 001 Device 008: ID 0403:6001 Future Technology Devices International, 
> >> Ltd FT232 Serial (UART) IC
> >
> > Have you tried usbserial_ftdi, e.g. GRUB_TERMINAL=usbserial_ftdi?
> > Just guessing...
>
> Yes, I tried (as I found the "usbserial_ftdi" string in the source)
> the but grub-mkconfig does not accecpt it:
>
> grub-mkconfig -o /boot/grub/grub.cfg
> Invalid output terminal "usbserial_ftdi"
>
> Currently I have this:
>
> GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyUSB0,115200n8"
> #GRUB_TERMINAL="console serial"
> GRUB_TERMINAL="serial"
> GRUB_SERIAL_COMMAND="usbserial_ftdi --speed=115200 --unit=0 --word=8 
> --parity=no --stop=1"
>
> But this does not seem to work either, even though I do get console
> output on my USB serial after the kernel has loaded (due to
> GRUB_CMDLINE_LINUX being passed to the kernel), e.g. I can do "echo
> hello > /dev/console" and read "hello" on the USB serial output. When
> I do a "reboot" I observe messages about unmounting filesystems etc.
>
> I was hoping to be able to select kernels and options in grub using
> the USB serial line.

Please take a look here:
  https://www.coreboot.org/GRUB2#On_a_USB_serial_or_USB_debug_adapter

I hope that helps.

Daniel