On devices with Hardware RNG (HW RNG), this makes EntropyMixer
periodically (every three hours) read 512 bytes from HW RNG and mix
them into the Linux RNG.
This is done without increasing Linux RNG's entropy estimates to
avoid having to trust the quality of the HW RNG. This approach cannot
reduce the quality of the Linux RNG output, but may increase it.
Change-Id: Ifde851004301ffd41b2189151a64a0c5989c630f
Write out entropy if we're shutting down or rebooting,
or if someone plugs in the power.
Bug: 8312061
Change-Id: Id9a48064a7bdfe6c05a9227ea95a1bdbd0e9b8ae
This does some cleanup of the initial boot, especially when
booting in "no core apps" mode for encryption/decryption.
Change-Id: Ifb3949f580e52f54559e603c4b0b104f6bac2f6c
EntropyService implies that this program provides entropy to other
programs, and is misleading. The EntropyMixer class is designed purely
to stir the existing entropy pool with some possibily random-ish data,
and carryover entropy across device reboots.
Change-Id: I086cd339a3b652d32371521e61e1b1f555ce2280
