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33 .Nd gather entropy from the kernel for the entropy device
38 .Fo random_harvest_direct
42 .Fa "enum esource source"
45 .Fo random_harvest_fast
49 .Fa "enum esource source"
52 .Fo random_harvest_queue
56 .Fa "enum esource source"
61 functions are used by device drivers
62 and other kernel processes to pass data
63 that is considered (at least partially) stochastic
64 to the entropy device.
66 The caller should pass
67 a pointer pointing to the
73 contains the number of bytes pointed to.
77 the values enumerated in
78 .Pa sys/dev/random.h .
79 and is used to indicate the source of the entropy.
82 .Fo random_harvest_direct
86 before any multitasking
90 .Fn random_harvest_fast
98 Some entropy is sacrificed,
99 but the high rate of supply
100 will compensate for this.
103 .Fn random_harvest_queue
105 for general harvesting
107 choice for most entropy sources
113 argument is only used
114 by the deprecated Yarrow algorithm.
117 .Em "very conservatively"
118 estimate the number of random bits
123 Interrupt harvesting has been
125 for the kernel programmer.
126 If a device driver registers an interrupt handler
130 .Xr bus_setup_intr 9 ,
131 then it is only necessary to
136 argument to have that interrupt source
137 be used for entropy harvesting.
138 This should be done wherever practicable.
146 entropy device and supporting documentation was written by
147 .An Mark R V Murray .