Re: [PATCH v2 00/14] efi/gop: Refactoring + mode-setting feature

From: Ard Biesheuvel
Date: Thu Mar 26 2020 - 06:41:14 EST


On Thu, 26 Mar 2020 at 00:36, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>
> On Wed, 25 Mar 2020 at 23:10, Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote:
> >
> > On Wed, Mar 25, 2020 at 05:41:43PM +0100, Ard Biesheuvel wrote:
> > > On Fri, 20 Mar 2020 at 03:00, Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote:
> > > >
> > > > This series is against tip:efi/core.
> > > >
> > > > Patches 1-9 are small cleanups and refactoring of the code in
> > > > libstub/gop.c.
> > > >
> > > > The rest of the patches add the ability to use a command-line option to
> > > > switch the gop's display mode.
> > > >
> > > > The options supported are:
> > > > video=efifb:mode=n
> > > > Choose a specific mode number
> > > > video=efifb:<xres>x<yres>[-(rgb|bgr|<bpp>)]
> > > > Specify mode by resolution and optionally color depth
> > > > video=efifb:auto
> > > > Let the EFI stub choose the highest resolution mode available.
> > > >
> > > > The mode-setting additions increase code size of gop.o by about 3k on
> > > > x86-64 with EFI_MIXED enabled.
> > > >
> > > > Changes in v2 (HT lkp@xxxxxxxxx):
> > > > - Fix __efistub_global attribute to be after the variable.
> > > > (NB: bunch of other places should ideally be fixed, those I guess
> > > > don't matter as they are scalars?)
> > > > - Silence -Wmaybe-uninitialized warning in set_mode function.
> > > >
> > >
> > > These look good to me. The only question I have is whether it would be
> > > possible to use the existing next_arg() and parse_option_str()
> > > functions to replace some of the open code parsing that goes on in
> > > patches 11 - 14.
> > >
> >
> > I don't think so -- next_arg is for parsing space-separated param=value
> > pairs, so efi_parse_options can use it, but it doesn't work for the
> > comma-separated options we'll have within the value.
> >
> > parse_option_str would only work for the "auto" option, but it scans the
> > entire option string and just returns whether it was there or not, so it
> > wouldn't be too useful either, since we have to check for the other
> > possibilities anyway.
> >
> > It would be nice to have a more generic library for cmdline parsing,
> > there are a lot of places that have to open-code option parsing like
> > this.
> >

OK, I have queued these up now in the EFI next branch, but this will
obviously have to wait for v5.8

Thanks