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From: Jens Wiklander <jens.wiklander@linaro.org>
Date: Tue, 23 Apr 2024 10:44:09 +0200
Message-ID: <CAHUa44F8J6byatNpg9W6Y2yinJw_RKEtLBKBSDxGkz0yx4Zi3A@mail.gmail.com>
Subject: Re: [PATCH v5 0/3] Replay Protected Memory Block (RPMB) subsystem
To: Avri Altman <Avri.Altman@wdc.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, 
	"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>, 
	"op-tee@lists.trustedfirmware.org" <op-tee@lists.trustedfirmware.org>, 
	Shyam Saini <shyamsaini@linux.microsoft.com>, Ulf Hansson <ulf.hansson@linaro.org>, 
	Linus Walleij <linus.walleij@linaro.org>, Jerome Forissier <jerome.forissier@linaro.org>, 
	Sumit Garg <sumit.garg@linaro.org>, Ilias Apalodimas <ilias.apalodimas@linaro.org>, 
	Bart Van Assche <bvanassche@acm.org>, Randy Dunlap <rdunlap@infradead.org>, 
	Ard Biesheuvel <ardb@kernel.org>, Arnd Bergmann <arnd@arndb.de>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On Tue, Apr 23, 2024 at 10:22=E2=80=AFAM Avri Altman <Avri.Altman@wdc.com> =
wrote:
>
> > On Tue, Apr 23, 2024 at 8:42=E2=80=AFAM Avri Altman <Avri.Altman@wdc.co=
m> wrote:
> > >
> > > > The OP-TEE driver finds the correct RPMB device to interact with by
> > > > iterating over available devices until one is found with a
> > > > programmed authentication matching the one OP-TEE is using. This
> > > > enables coexisting users of other RPMBs since the owner can be
> > > > determined by who knows the authentication key.
> > > Devices in plural?
> > > I am unaware of any board with multi eMMC devices soldered.
> > > Can you refer me to such a platform?
> >
> > I'm testing with a Hikey960 (HiSilicon Kirin 620)
> > https://www.96boards.org/product/hikey
> > It has one soldered eMMC and one removable eMMC.
> I used to have that board but with a UFS2.1 version, so I can't really te=
ll.
> https://github.com/96boards/documentation/blob/master/consumer/hikey/hike=
y620/hardware-docs/hardware-user-manual.md#storage
> indicating only a single eMMC device and a SD.

That's what I'm testing with, the kernel finds two RPMBs with
different CIDs. I'm running my tests with the removable one.

> Either way, AFAIK there are no production designs that make use of more t=
han a single embedded flash storage.
> This goes for both eMMC and UFS.

OK

Thanks,
Jens