Re: FTDI serial console support?

[Daniel Kiper]

On Sat, May 26, 2018 at 07:21:24AM +0200, Petter Gustad wrote:
> From: Andrew Worsley <address@hidden>
> Subject: Re: FTDI serial console support?
> Date: Sat, 19 May 2018 23:12:42 +1000
>
> > On 19 May 2018 at 00:32, Petter Gustad <address@hidden> wrote:
> >> From: Daniel Kiper <address@hidden>
> >> Subject: Re: FTDI serial console support?
> >> Date: Fri, 18 May 2018 13:55:55 +0200
> >>
> >>> On Fri, May 18, 2018 at 01:01:41PM +0200, Petter Gustad wrote:
> >>>> From: Daniel Kiper <address@hidden>
> >>>> Subject: Re: FTDI serial console support?
> >>>> Date: Wed, 16 May 2018 11:32:19 +0200
> >>>>
> >>>> > 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:
> >>>> >> >>
> > ....
> >>> Could you just do "insmod usbserial_ftdi"? There is a chance that it
> >>> will pull in all needed dependencies without breaking disk access.
> >>
> >> Thanks. Only "insmod usbserial_ftdi" does work in the sense that it
> >> will not break disk access. I also managed to load grub using PXE/tftp
> >> where I was not dependend upon disk access.
> >>
> >> But in both cases it does not work like in the coreboot URL above.
> >> After do insmod on usbserial_ftdi and usbserial_usbdebug the
> >> terminal_output command will only return console as its active output
> >> terminal. It will list serial_* as available output terminals, but I
> >> can't select usb0, usb1, etc as argument to the serial command.
> >
> > I think GRUB relies on the BIOS/UEIF to provide drivers and typically
> > USB  was only
> > used to emulated old hardware like keyboard/mouse  and CD-ROMs.
> >
> > Coreboot - is a BIOS/UEIF replacement and so it can do anything they
> > care to implement - but then it has to be
> > customised for each individual hardware case where as GRUB can rely on
> > the standardised routines.
> >
> > But perhaps things have moved on - it would be great if UEIF provided
> > some standard USB drivers for serial.
>
> Thank you Andrew and Daniel for information and suggestions. Seems

You are welcome!

> like I have to figure out what drivers are provided with UEIF. Or
> simply just get another motherboard with a 8250/16550 compatible
> serial port.

I think that this is the simplest solution at this point. Anyway,
I will try to take a look at this issue when I less busy.

Daniel