"Bad address" reading /dev/mem

chvince · 12-03-2008, 04:05 PM

I have 2G RAM, but I get this:

localhost:~# dd if=/dev/mem bs=1024 >/dev/null
dd: reading `/dev/mem': Bad address
917504+0 records in
917504+0 records out
939524096 bytes (940 MB) copied, 1.16839 seconds, 804 MB/s

Why can't I read above 917504 kbytes?

pixellany · 12-03-2008, 06:06 PM

What is /dev/mem and how does it compare to /proc/kcore?

(I don't know the answer, but the secret lies in understanding Linux memory management which, according to my reading, is not a trivial undertaking)

If it makes you feel any better, my system gives the same result, but takes 1/10th of a second longer.