QNX /dev/mem size is too big


Would someone please kindly tell me what the /dev/mem directory does.
And why its size is so big. Im running QNX off the CD …on closer inspection of /dev/mem.

du -k mem reveals that the size of this file is 4194304 KBytes … 4 Gigs ?

I have made several images on compact flash — (they running fine ) and when I had a look at the /dev/mem file on these compact flash images it is also a huge file …i think it was 4 or 8 gigs (can’t remember exact value) which is impossible as Cf card is only 256 MB. When viewed via qconn the file size is reported to be -1. I suspect this is due to overflow in the file size reported.

Any help with this would be appreciated.


It’s not a real file. It’s actuall a device that maps the WHOLE adressable memory, whether it exists or not.