Re: reading BIOS dump

Randy Howard wrote:
On Fri, 29 Dec 2006 19:59:34 -0600, CBFalconer wrote
Randy Howard wrote:
On Fri, 29 Dec 2006 17:02:07 -0600, Bill Cunningham wrote

The answer to the OP's question is it starts at f0000 (f000:0000
for the old DOS crowd). You can open /dev/mem, seek to that
address and read it as if it were a file. It's the entire
"segment", or 64K in length.

Instead of going to the trouble to write a small C program what
about using the dd command. Copy if=/dev/mem to of= and use bs=64k
and seek=0xffff0 ? Would that work ? I'll try it if it sounds safe
I don't want to screw up my system.

Reading from /dev/mem can't hurt your system. Writing to it is
another matter entirely.

What if i/o is memory mapped? Reading a location may reset a
'ready' flag and/or empty a hardware buffer.

The original form of this question was in reference to Linux boxes. I
know of none that have such a problem to be worried about. Do you?

Don't MACs use memory mapped i/o and run Linux? At least older
ones.

--
Merry Christmas, Happy Hanukah, Happy New Year
Joyeux Noel, Bonne Annee.
Chuck F (cbfalconer at maineline dot net)
<http://cbfalconer.home.att.net>


.