linux-kernel - Re: [PATCH 4/5] efi: Export Runtime Configuration Interface table to sysfs

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Message-ID: <CAMuHMdV9m+Dbch46cVNqtn4cyB74qgHa18Qcm=HQv7Wx1rk==w@mail.gmail.com>
Date:   Tue, 1 Oct 2019 11:03:37 +0200
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc:     Narendra K <Narendra.K@...l.com>,
        linux-efi <linux-efi@...r.kernel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        James Morse <james.morse@....com>,
        Mario Limonciello <mario.limonciello@...l.com>,
        Xiaofei Tan <tanxiaofei@...wei.com>
Subject: Re: [PATCH 4/5] efi: Export Runtime Configuration Interface table to sysfs

Hi Ard,

On Tue, Oct 1, 2019 at 10:54 AM Ard Biesheuvel
<ard.biesheuvel@...aro.org> wrote:
> On Tue, 1 Oct 2019 at 10:51, Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
> > On Mon, Aug 12, 2019 at 5:07 PM Ard Biesheuvel
> > <ard.biesheuvel@...aro.org> wrote:
> > > From: Narendra K <Narendra.K@...l.com>
> > >
> > > System firmware advertises the address of the 'Runtime
> > > Configuration Interface table version 2 (RCI2)' via
> > > an EFI Configuration Table entry. This code retrieves the RCI2
> > > table from the address and exports it to sysfs as a binary
> > > attribute 'rci2' under /sys/firmware/efi/tables directory.
> > > The approach adopted is similar to the attribute 'DMI' under
> > > /sys/firmware/dmi/tables.
> > >
> > > RCI2 table contains BIOS HII in XML format and is used to populate
> > > BIOS setup page in Dell EMC OpenManage Server Administrator tool.
> > > The BIOS setup page contains BIOS tokens which can be configured.
> > >
> > > Signed-off-by: Narendra K <Narendra.K@...l.com>
> > > Reviewed-by: Mario Limonciello <mario.limonciello@...l.com>
> > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
> >
> > Thanks, this is now commit 1c5fecb61255aa12 ("efi: Export Runtime
> > Configuration Interface table to sysfs").
> >
> > > --- a/drivers/firmware/efi/Kconfig
> > > +++ b/drivers/firmware/efi/Kconfig
> > > @@ -180,6 +180,19 @@ config RESET_ATTACK_MITIGATION
> > >           have been evicted, since otherwise it will trigger even on clean
> > >           reboots.
> > >
> > > +config EFI_RCI2_TABLE
> > > +       bool "EFI Runtime Configuration Interface Table Version 2 Support"
> > > +       help
> > > +         Displays the content of the Runtime Configuration Interface
> > > +         Table version 2 on Dell EMC PowerEdge systems as a binary
> > > +         attribute 'rci2' under /sys/firmware/efi/tables directory.
> > > +
> > > +         RCI2 table contains BIOS HII in XML format and is used to populate
> > > +         BIOS setup page in Dell EMC OpenManage Server Administrator tool.
> > > +         The BIOS setup page contains BIOS tokens which can be configured.
> > > +
> > > +         Say Y here for Dell EMC PowerEdge systems.
> >
> > A quick Google search tells me these are Intel Xeon.
> > Are arm/arm64/ia64 variants available, too?
> > If not, this should be protected by "depends on x86" ("|| COMPILE_TEST"?).
>
> The code in question is entirely architecture agnostic, and defaults
> to 'n', so I am not convinced this is needed. (It came up in the
> review as well)

"make oldconfig" still asks me the question on e.g. arm64, where it is
irrelevant, until arm64 variants of the hardware show up.

So IMHO it should have "depends on X86 || COMPILE_TEST".

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds