Re: FTDI serial console support?

[Petter Gustad]

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.

Best regards
//Petter