> I was trying to read something from near the end of /dev/mem yesterday with
> 
> # dd if=/dev/mem bs=32768 skip=65536 count=1
> 
> (I wanted a copy of the eprom image from my pc532...)
> the response I got was:
> 
> dd: seek offsets cannot be larger than 2147483647

dd is probably easily fixed to allow larger offsets.

But you might be in for other surprises if you use dd to read /dev/mem
this way. Representing physical memory, /dev/mem might contain holes
that dd will stumble on. On character devices, dd doesn't use lseek(),
but rather just reads blocks until it gets where it wants to be; not always
pleasant. Also, you might run over mapped devices on some architectures,
reading their registers etc., and making some of them unhappy..

-pk