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Subject/dev/random oddness
Date
Hi,

I've just had a report that I've confirmed that /dev/random on ARM doesn't
behave the same as /dev/random on x86.

I've confirmed this by comparing a NetWinder with an IBM thinkpad. Both these
have PS/2 mice. The NetWinder is running 2.3.41, which uses the standard
random.c and pc_keyb.c sources. The thinkpad is running untouched 2.2.12 at
the moment.

On the thinkpad, doing an 'od -t x1 -Ax /dev/random' and moving the mouse in
a console results in a lot of bytes being generated from the device. However,
on a NetWinder, it results in very few, less than 1/10th of what the x86
machine produces.

I have also compared it with other ARM architectures (on 2.2.14) use the
busmice code (which got added to 2.3 iirc) to add randomness, and that behaves
in the same manner as the NetWinder.

Does anyone have any clues what might be causing this odd behaviour? I haven't
scanned over random.c in any great depth yet.
_____
|_____| ------------------------------------------------- ---+---+-
| | Russell King rmk@arm.linux.org.uk --- ---
| | | | http://www.arm.linux.org.uk/~rmk/aboutme.html / / |
| +-+-+ --- -+-
/ | THE developer of ARM Linux |+| /|\
/ | | | --- |
+-+-+ ------------------------------------------------- /\\\ |

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