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33 .Nd gather entropy from the kernel for the entropy device
42 .Fa "enum esource source"
47 function is used by device drivers
48 and other kernel processes to pass data
49 that is considered (at least partially) stochastic
50 to the entropy device.
52 The caller should pass a pointer (to no more than 16 bytes) of
59 contains the number of bytes pointed to.
61 .Em "very conservatively"
62 estimate the number of random bits
68 If the estimated number of bits per sample is an integer, then
74 for low-entropy samples,
76 entropy can be supplied in
78 (This is considered to be
80 1024 bits of entropy.)
84 .Dv RANDOM_WRITE , RANDOM_KEYBOARD , RANDOM_MOUSE , RANDOM_NET
86 .Dv RANDOM_INTERRUPT ,
87 and is used to indicate the source of the entropy.
89 Interrupt harvesting has been simplified
90 for the kernel programmer.
91 If a device driver registers an interrupt handler
95 .Xr bus_setup_intr 9 ,
96 then it is only necessary to
101 argument to have that interrupt source
102 be used for entropy harvesting.
110 entropy device and supporting documentation was written by
111 .An Mark R V Murray .