Re: VIA Padlock on AMD64

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

> Date: Wed, 22 Jul 2020 03:17:21 +0300
> From: Andrius V <vezhlys%gmail.com@localhost>
> 
> Not sure how useful to work on this though. Linux doesn't seem to have
> newer graphics IDs in VIA DRM driver too (possibly abandoned over new
> effort?). Currently Xorg server starts on VX900, but screen complains
> with "Input signal is out of range" error with or without viadrmums
> driver, so I can't see anything on the screen (maybe I need some
> manual xorg configuration). I don't remember if it was the case
> before, I usually used console only.

Is there any documentation for the graphics hardware?  Is hardware
available on the market in the US?  (Can you send me any?)

> Unrelated, but I think it appeared pretty recently in dmesg logs and
> related to your changes:
> [   4.0518619] aes: VIA ACE
> ....
> [  11.7018582] cpu_rng via: failed repetition test
> T[  12.4718583] entropy: ready
> 
> Before it was:
> cpu_rng: VIA
> rnd: seeded with 256 bits

Cool!  Is it reproducible?  You can trigger reading from the RNG with:

sysctl kern.entropy.gather=1

I don't think I've changed anything in the past month or so that would
affect it -- more likely, this is a stochastic (and perhaps transient)
failure of the RNG hardware.  I also see a likely bug in the VIA
cpu_rng code judging by the Padlock documentation -- should be easy to
fix, once the air here cools down enough to boot up my VIA laptop
without setting fire to the table.