Re: [PATCH] efi: EFI_EARLYCON should depend on EFI

From: Ard Biesheuvel
Date: Wed Nov 25 2020 - 03:23:14 EST


On Wed, 25 Nov 2020 at 09:21, Damien Le Moal <Damien.LeMoal@xxxxxxx> wrote:
>
> On Tue, 2020-11-24 at 20:16 +0100, Geert Uytterhoeven wrote:
> > CONFIG_EFI_EARLYCON defaults to yes, and thus is enabled on systems that
> > do not support EFI, or do not have EFI support enabled, but do satisfy
> > the symbol's other dependencies.
> >
> > While drivers/firmware/efi/ won't be entered during the build phase if
> > CONFIG_EFI=n, and drivers/firmware/efi/earlycon.c itself thus won't be
> > built, enabling EFI_EARLYCON does force-enable CONFIG_FONT_SUPPORT and
> > CONFIG_ARCH_USE_MEMREMAP_PROT, and CONFIG_FONT_8x16, which is
> > undesirable.
> >
> > Fix this by making CONFIG_EFI_EARLYCON depend on CONFIG_EFI.
> >
> > This reduces kernel size on headless systems by more than 4 KiB.
> >
> > Fixes: 69c1f396f25b805a ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation")
> > Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > ---
> > drivers/firmware/efi/Kconfig | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
> > index b452cfa2100b401c..1dd1f7784f0888ff 100644
> > --- a/drivers/firmware/efi/Kconfig
> > +++ b/drivers/firmware/efi/Kconfig
> > @@ -270,7 +270,7 @@ config EFI_DEV_PATH_PARSER
> >
> >
> > config EFI_EARLYCON
> > def_bool y
> > - depends on SERIAL_EARLYCON && !ARM && !IA64
> > + depends on EFI && SERIAL_EARLYCON && !ARM && !IA64
> > select FONT_SUPPORT
> > select ARCH_USE_MEMREMAP_PROT
> >
> >
>
> Looks good to me.
> Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
>

Thanks all

I'll queue this as a fix.