Re: tpm_tis TPM2.0 not detected on cold boot

[Michael Niewöhner]

On Thu, 2019-01-03 at 15:27 +0200, Jarkko Sakkinen wrote:
> On Sun, Dec 23, 2018 at 12:55:12PM +0100, Michael NiewÃhner wrote:
> > There is another issue but I don't know if both are related. Maybe that's
> > just a
> > timing issue...
> > 
> > root@debian:~# dd if=/dev/hwrng bs=1 count=1
> > dd: error reading '/dev/hwrng': Operation not permitted
> > 0+0 records in
> > 0+0 records out
> > 0 bytes copied, 0.755958 s, 0.0 kB/s
> > root@debian:~# dd if=/dev/hwrng bs=1 count=1 | xxd; dd if=/dev/hwrng bs=1
> > count=1 | xxd
> > dd: error reading '/dev/hwrng': Operation not permitted
> > 0+0 records in
> > 0+0 records out
> > 0 bytes copied, 0.755697 s, 0.0 kB/s
> > 1+0 records in
> > 1+0 records out
> > 00000000: 52                                       R
> > 1 byte copied, 0.0106268 s, 0.1 kB/s
> > 
> > 
> > Michael
> 
> What does /sys/devices/virtual/misc/hw_random/rng_current show?
> 
> Did run commands as a sanity check on my laptop and seem to work.
> 
> /Jarkko

rng_current says "tpm-rng-0", which should be correct


Michael