Re: grub2 and touch screen

[Andrei Borzenkov <arvidjaar@gmail.com>]

В Fri, 26 Jun 2015 15:27:35 +0700
"Fajar A. Nugraha" <list@fajar.net> пишет:

> On Fri, Jun 26, 2015 at 3:14 PM, Andrei Borzenkov <arvidjaar@gmail.com> wrote:
> > В Wed, 24 Jun 2015 14:06:42 +0200
> > Theodore Christophe <mission_theodore@hotmail.com> пишет:
> >
> >> hello all,
> >>
> >> First of all, thank-you for your works.
> >>
> >> I have installed Fedora21 on my laptop (Medion all in one) with dual
> >> boot, and every-thing is working fine.
> >> Grub2 give me the choice between win8.1 and FC21, and other rescue.
> >>
> >> BUT when I use my laptop as touch pad (by removing the screen), with no
> >> keyboard, I could not select the boot I want to use. Fedora is the
> >> default and the touch screen is working fine after.
> >>
> >> Do you think that grub can manage the touch screen (something like two
> >> button win81 and FC21) ?
> >>
> >
> > Somebody would need to write driver for it (assuming it is technically
> > possible in firmware at all). I think I have seen reports that using
> > hardware buttons worked for selecting menu entries, but it may be
> > hardware dependent.
> >
> > As Michael, I think adding support for hardware buttons looks more
> > promising.
> 
> 
> How does grub currently support the hardware buttons?
> 

It does not, in the sense there is no explicit code to do it I'm aware
of. It just relies on EFI to return character (key stroke).

> On Asus T300 Chi, the EFI boot menu reads volume + and - buttons as up
> and down, while windows button function as "enter". However grub reads
> volume + as "enter" as well, so I only have volume - (down) for moving
> between menu entries.
> 

To debug it access to hardware is needed, which is why it is quite hard
to fix such things. If you are willing to debug it, file bug report on
savannah, we'll need to dump read keystroke information to find out
what you hardware returns. I do not see anything in grub code that
would account for it at the first glance.