From: clabbe.montjoie@gmail.com (LABBE Corentin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] nvmem: sunxi-sid: SID content is not a valid source of randomness
Date: Fri, 28 Oct 2016 14:37:20 +0200 [thread overview]
Message-ID: <20161028123720.GA10889@Red> (raw)
In-Reply-To: <20161025090634.3dae9ad52ae8382dde6af4c8@free.fr>
On Tue, Oct 25, 2016 at 09:06:34AM +0200, Jean-Francois Moine wrote:
> On Tue, 25 Oct 2016 07:38:55 +0200
> LABBE Corentin <clabbe.montjoie@gmail.com> wrote:
>
> > > On Sat, Oct 22, 2016 at 03:53:28PM +0200, Corentin Labbe wrote:
> > > > Since SID's content is constant over reboot,
> > >
> > > That's not true, at least not across all the Allwinner SoCs, and
> > > especially not on the A10 and A20 that this driver supports.
> > >
> >
> > On my cubieboard2 (A20)
> > hexdump -C /sys/devices/platform/soc\@01c00000/1c23800.eeprom/sunxi-sid0/nvmem
> > 00000000 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> > 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> > *
> > 00000100 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> > 00000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> > *
> > 00000200
> > cubiedev ~ # reboot
> > cubiedev ~ # hexdump -C /sys/devices/platform/soc\@01c00000/1c23800.eeprom/sunxi-sid0/nvmem
> > 00000000 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> > 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> > *
> > 00000100 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> > 00000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> > *
> > 00000200
> >
> > So clearly for me its constant.
>
> Even after power off/power on?
Yes, even after remove of any power supply.
next prev parent reply other threads:[~2016-10-28 12:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-22 13:53 [PATCH] nvmem: sunxi-sid: SID content is not a valid source of randomness Corentin Labbe
2016-10-24 20:10 ` Maxime Ripard
2016-10-25 5:38 ` LABBE Corentin
2016-10-25 7:06 ` Jean-Francois Moine
2016-10-28 12:37 ` LABBE Corentin [this message]
2016-10-25 13:26 ` Maxime Ripard
2016-11-10 15:14 ` Corentin Labbe
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