Collecting entropy from device_attach() times.

[Dag-Erling Smørgrav]

Dag-Erling Smørgrav <des at des.no> writes:
> http://people.freebsd.org/~des/attachtimes-text.txz

1) There is a bug in the program - I made a couple of changes which I
   didn't like but didn't fully revert.  The (argc != 0) in main()
   should actually be (argc == 0).

2) I modified the program to create a histogram of the lower bits and
   looked at that in gnuplot.  It was immediately obvious that the
   distribution is extremely non-uniform.  I suspect that this is - at
   least in part - due to the weird way get_cyclecount() computes the
   value it returns.  We should either rewrite it to return something
   sensible or nuke it and use binuptime() instead.

I uploaded a new tarball with the improved program and the histogram:

  http://people.freebsd.org/~des/attachtimes-total.txz

DES
-- 
Dag-Erling Smørgrav - des at des.no