d2704808f2
To allow this device to fill the kernel's entropy pool at boot, setup a default quality for the hwrng found in Cr50. After some testing with rngtest and dieharder it was, in short, discovered that the RNG produces fair quality randomness, giving around 99.93% successes in rngtest FIPS140-2. Notably, though, when testing with dieharder it was noticed that we get 3 WEAK results over 114, which isn't optimal, and also the p-values distribution wasn't uniform in all the cases, so a conservative quality value was chosen by applying an arbitrary penalty to the calculated values. For reference, this is how the values were calculated: The dieharder results were averaged, then normalized (0-1000) and re-averaged with the rngtest result (where the result was given a score of 99.93% of 1000, so 999.3), then aggregated together and averaged again. An arbitrary penalty of -100 was applied due to the retrieved value, which brings us finally to 700. Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.