HAB warning on imx6sx

[Stefano Manni]

Hi,

On Tue, 2024-07-23 at 14:24 +0200, Rouven Czerwinski wrote:
> 
> This is a common warning on some i.MX6 devices which indicates a CAAM
> RNG self-test failure, see the description in
> drivers/crypto/caam/rng_self_test.c which should be run by the
> bootloader to ensure that the RNG part of the CAAM is not faulty.
> This requires the CAAM driver within barebox to be enabled.
> 

after enabling CAAM I see:

  rng_self_test: RNG software self-test passed
  caam 2100000.crypto at 2100000.of: Instantiated RNG4 SH1

but the HAB warning is still there.

I read from drivers/crypto/caam/rng_self_test.c that the warning is
a false positive due to an incorrect implementation of the RNG
self-test procedure in the boot ROM.
So running the RNG selftest in the bootloader shoul help find
real RNG failures that may be obfuscated by this false positive.

Is correct my understanding?

Best,
Stefano