Could you please update the hwrng package? After the update, the "read error" messages when rngd is being started should not show any more and the daemon should not crash.
https://git.ipfire.org/?p=ipfire-2.x.git;a=commitdiff;h=90940aded5b7e233fadaae8bad8efbdfe383ce6c
Core 122 has been shipped; this is fixed. Just cleaning up some bugs... :-)