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33 .Nd gather entropy from the kernel for the entropy device
43 .Fa "enum esource source"
48 function is used by device drivers
49 and other kernel processes to pass data
50 that is considered (at least partially) stochastic
51 to the entropy device.
53 The caller should pass a pointer (to no more than 16 bytes) of
60 contains the number of bytes pointed to.
62 .Em "very conservatively"
63 estimate the number of random bits
69 If the estimated number of bits per sample is an integer, then
75 for low-entropy samples,
77 entropy can be supplied in
79 (This is considered to be
81 1024 bits of entropy.)
85 .Dv RANDOM_WRITE , RANDOM_KEYBOARD , RANDOM_MOUSE , RANDOM_NET
87 .Dv RANDOM_INTERRUPT ,
88 and is used to indicate the source of the entropy.
90 Interrupt harvesting has been simplified
91 for the kernel programmer.
92 If a device driver registers an interrupt handler
96 .Xr bus_setup_intr 9 ,
97 then it is only necessary to
102 argument to have that interrupt source
103 be used for entropy harvesting.
111 entropy device and supporting documentation was written by
112 .An Mark R V Murray .