Re: [PATCH] firmware: export x86_64 platform flash bios region via sysfs - Hans-Gert Dahmen

From: Hans-Gert Dahmen <hans-gert.dahmen@immu.ne>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mauro Lima <mauro.lima@eclypsium.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Philipp Deppenwiese <philipp.deppenwiese@immu.ne>,
	Richard Hughes <hughsient@gmail.com>,
	"platform-driver-x86@vger.kernel.org" 
	<platform-driver-x86@vger.kernel.org>
Subject: Re: [PATCH] firmware: export x86_64 platform flash bios region via sysfs
Date: Thu, 11 Nov 2021 09:59:32 +0100	[thread overview]
Message-ID: <CAHifhD5bXu2nP533RXyWDnyNt=k2rRZq5Z6A6CCik_2e6XNgGA@mail.gmail.com> (raw)
In-Reply-To: <YYy7QZGKeEEfI1mH@lahna>

Am Do., 11. Nov. 2021 um 07:42 Uhr schrieb Mika Westerberg
<mika.westerberg@linux.intel.com>:
>
> Hi,
>
> On Wed, Nov 10, 2021 at 02:37:56PM -0300, Mauro Lima wrote:
> > > Try again to collaborate with Intel SPI driver author(s) /
> > > maintainer(s) by sending the proposal that may work.
> >
> > The proposal I sent makes the driver work only with read ops, but that
> > was not the issue with this driver. The issue was something related to
> > a status register and this was fixed. So if there is no issue with
> > write/erase ops, the bug was fixed and there is no intention to remove
> > the tag. What kind of proposal are we talking about?
>
> I think we discussed this previously already but in any case, instead of
> removing the tag from the "main" driver, we can make certain "safe"
> parts of the driver available without that tag. That would allow you to
> read the things the controller exposes and allow distros safely include
> the driver too. By "safe" parts, I mean the information available
> through the SPI flash controller without actually sending commands to
> the flash chip. I think this is the information everybody (on this
> thread at least) is interested in. Unless I'm mistaken - I did not check

Yes you are mistaken. My patch is about safely reading the BIOS/UEFI
binary on every past and future x86_64 system. There are tools out
there that use the interface my patch uses and they can not work any
longer when /dev/mem is locked down with SecureBoot enabled. The
tools, like fwupd, should work out-of-the-box on the typical
distribution. During this discussion we were told that my patch is not
welcome and that we have to work with you to achieve the same. So I'm
curious to hear how that can be done.

> the original patch. If that's not enough we can possibly expand it to
> cover the controllers that only use hardware sequencer since they
> operate on a certain limited set of ops that should not break anything
> accidentally.

Hans-Gert