Hi, Am 20.11.19 um 20:50 schrieb Nicolas Saenz Julienne: > On Wed, 2019-11-20 at 17:16 +0100, Stefan Wahren wrote: >> Hi Stephen, >> >> Am 20.11.19 um 04:16 schrieb Stephen Brennan: >>> This patch series enables support for the HWRNG included on the Raspberry >>> Pi 4. It is simply a rebase of Stefan's branch [1]. I went ahead and >>> tested this out on a Pi 4. Prior to this patch series, attempting to use >>> the hwrng gives: >>> >>> $ head -c 2 /dev/hwrng >>> head: /dev/hwrng: Input/output error >>> >>> After this series, the same command gives two random bytes. >> just a note: a more expressive test would be running rngtest (package >> rng-tools) on this device. > Just had a go at it, > > root@rpi4:~# rngtest -c 1000 < /dev/hwrng > rngtest 2-unofficial-mt.14 > Copyright (c) 2004 by Henrique de Moraes Holschuh > This is free software; see the source for copying conditions. There is NO > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. > > rngtest: starting FIPS tests... > rngtest: bits received from input: 20000032 > rngtest: FIPS 140-2 successes: 998 > rngtest: FIPS 140-2 failures: 2 > rngtest: FIPS 140-2(2001-10-10) Monobit: 0 > rngtest: FIPS 140-2(2001-10-10) Poker: 1 > rngtest: FIPS 140-2(2001-10-10) Runs: 0 > rngtest: FIPS 140-2(2001-10-10) Long run: 1 > rngtest: FIPS 140-2(2001-10-10) Continuous run: 0 > rngtest: input channel speed: (min=1.284; avg=113.786; max=126.213)Kibits/s > rngtest: FIPS tests speed: (min=17.122; avg=28.268; max=28.812)Mibits/s > rngtest: Program run time: 172323761 microseconds > > AFAIR (Arch wiki) some small failures are acceptable. > > Regards, > Nicolas > thanks for the results. AFAIR the downstream implementation [1] has a significant higher input speed. So there is possibly some room for optimizations later. Regards Stefan [1] - https://github.com/raspberrypi/linux/commit/5e74aadfd1e0e6c00994521863ba044ce25b40de