From: Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>
To: Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Greg Bellows
<greg.bellows-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"devicetree-spec-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<devicetree-spec-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Christoffer Dall
<christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
Peter Maydell
<peter.maydell-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
"grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org"
<grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Subject: Re: Secure resources in device trees
Date: Wed, 21 Jan 2015 18:08:34 +0000 [thread overview]
Message-ID: <1421863714.14076.103.camel@arm.com> (raw)
In-Reply-To: <CAL_Jsq+rN07CfdNjErhLipKNJJj3uoczR98YuWSAwjMRW1xVag-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Wed, 2015-01-21 at 16:21 +0000, Rob Herring wrote:
> > * Not possible to identify whether a device is shared or not between
> > the secure and non-secure worlds.
>
> Typically, sharing requires a peripheral to be designed to be shared
> like PL330 or MMU-400. I have seen some h/w with locking registers so
> 2 different cores/OSs can share an i2c bus. You could do something
> like that for Trustzone as well I suppose. That's not really secure,
> but allows shared access. I think it is generally a limited number of
> peripherals which are shared.
Interestingly enough, the most common case for a shared peripheral is a
keypad/keyboard for secure PIN entry. A secure-programmable-only filter
like TZC-400 can be used to change the "designation" of a AXI master
connected to it.
Pawel
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next prev parent reply other threads:[~2015-01-21 18:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-20 19:15 Secure resources in device trees Greg Bellows
[not found] ` <CAOgzsHVpXZTHoq7HyfrGeGe92onnb6=BQr30PvKrg04h=0De0w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-21 16:21 ` Rob Herring
[not found] ` <CAL_Jsq+rN07CfdNjErhLipKNJJj3uoczR98YuWSAwjMRW1xVag-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-21 16:29 ` Grant Likely
2015-01-21 17:23 ` Greg Bellows
2015-01-21 18:08 ` Pawel Moll [this message]
2015-01-22 11:09 ` Peter Maydell
2015-01-21 16:29 ` Mark Rutland
2015-01-21 17:43 ` Rob Herring
[not found] ` <CAL_JsqJDNziqcX-8cq0PkSE61NVpmSBUM+fo3vmD3WrBG3=R7Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-22 18:27 ` Mark Rutland
2015-01-21 18:01 ` Greg Bellows
[not found] ` <CAOgzsHWyissYN+v5XHvUic3tp0EMHvrwTnLou2RRbyBp_9MmdQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-21 18:05 ` Christoffer Dall
[not found] ` <CAMJs5B_0sOSh4dLB9EyM2vaJq21YaXV6bX_zAv8Vmweq99DARA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-21 18:07 ` Greg Bellows
2015-01-22 11:14 ` Peter Maydell
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