This adds an implementation of Xoroshiro128+ PRNG, based on the
original implementation at [1]. This pseudorandom number generator
will use the entropy driver to obtain the seed.
While it uses only 128 bits of state, it's pretty robust for non-crypto
safe applications.
[1] http://vigna.di.unimi.it/xorshift/xoroshiro128plus.c
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Instead of every hardware number generator driver providing an
implementation of this function, use the random device API to
centralize the implementation of this function.
This is a very simplistic function that can be seen as a stepping stone
to refactor the random number generation in Zephyr.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
This should clear up some of the confusion with random number
generators and drivers that obtain entropy from the hardware. Also,
many hardware number generators have limited bandwidth, so it's natural
for their output to be only used for seeding a random number generator.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Some "random" drivers are not drivers at all: they just implement the
function `sys_rand32_get()`. Move those to a random subsystem in
preparation for a reorganization.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Leandro Pereira