HAB warning on imx6sx

[Rouven Czerwinski]

Hi,

On Tue, 2024-07-23 at 14:09 +0200, Stefano Manni wrote:
> Hello,
> 
> on a board based on imx6sx I'm facing the following warning when
> HABv4
> is enabled on barebox 2024.02:
> 
> ERROR: HABv4: -------- HAB Event 0 --------
> ERROR: HABv4: event data:
> ERROR: HABv4:  db 00 24 42  69 30 e1 1d
> ERROR: HABv4:  00 08 00 02  40 00 36 06
> ERROR: HABv4:  55 55 00 03  00 00 00 00
> ERROR: HABv4:  00 00 00 00  00 00 00 00
> ERROR: HABv4:  00 00 00 01
> ERROR: HABv4: Status: Operation completed with warning (0x69)
> ERROR: HABv4: Reason: Engine failure (0x30)
> ERROR: HABv4: Context: Event logged in hab_rvt.entry() (0xe1)
> ERROR: HABv4: Engine: CAAM (0x1d)
> 
> Have you ever experienced something like this? On another board based
> on on imx6ul I've never seen it.
> 
> Should I ignore it? Maybe it disappears when I secure the device?

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.

Best regards,
Rouven Czerwinski