[PATCH v2 2/2] Port to new board "VoCore2"

[Weijie Gao <weijie.gao@mediatek.com>]

Hi Mauro,

As far as I know MT7628 only has a hw crypto engine.

I have only the same programming guide as yours so I can't tell you what
does the "RESV1 Select Random Generator mode" mean.

Best Regards,

Weijie

On Wed, 2020-01-08 at 14:37 +0100, Daniel Schwierzeck wrote:
> +cc Weijie
> 
> On 1/7/20 6:43 PM, Mauro Condarelli wrote:
> > Thanks Daniel.
> > 
> > On 1/7/20 4:58 PM, Daniel Schwierzeck wrote:
> >> On Tue, Jan 7, 2020 at 3:30 PM Mauro Condarelli <mc5686@mclink.it> wrote:
> >> ...
> >>> I also have problems with entropy pool in Linux, do you happen to know
> >>> if (and how) MT7628 supports HWRNG?
> >> what problems exactly?
> > Currently it takes a LOT of time to fill-up the entropy pool
> > (over half an hour) and on first startup, when it has to
> > generate ssh keys and other stuff system is virtually dead
> > for that long.
> 
> if possible you should generate the host keys on the first SSH
> connection attempt. Otherwise the time of generation is predictable. If
> you use dropbear you can configure that.
> 
> >>
> >> On a embedded device you usually can only add randomness from
> >> interrupts sources to the entropy pool
> >> due to lack of disk or input devices. On a router the most interrupts
> >> are typically generated by drivers
> >> for ethernet and SPI/NAND/MMC controllers. You could use user-space
> >> daemons like haveged [1]
> >> to add more randomness from hardware events.
> > I tried that and it helps.
> > I also found *traces* pointing in the direction of hardware
> > support for RNG in my SoC; I have ca opy of the (badly
> > incomplete) "MT7628 PROGRAMMING GUIDE" and it
> > reports in "PWM1 Control register" an "interesting" field:
> > RESV1 Select Random Generator mode.
> > This males a lot of sense because this SoC is meant to implement
> > Wireless routers, so crypto and random acceleration would
> > be very useful.
> > Unfortunately I don't have more precise information, hence
> > the question.
> 
> maybe Weijie from Mediatek can tell if MT7628 has a HWRNG. But PWM1
> sounds more like a pulse width modulator and shouldn't be related to a
> HWRNG.
>