Orlando Llanes wrote:

How would I do low level access for memory with a normal user privilege? Why can't I just define a pointer and write data to it? Ugh, Linux is a good OS, but it can be a pain in the butox :P

Of course you can do it this way for your (i.e. this process's) memory. Sorry if I didn't make this clear. You need root privileges to access all memory -- that's the point of memory protection in a good OS (because a normal program can't accidentally overwrite/crash other processes or the kernel).

The other thing is (as far as I've understood it so far) that Linux uses paging, so the same pointer doesn't necessarily mean the same thing in two different processes (because the memory of these processes is paged differently). Therefore, there's the /dev/mem device to allow you (i.e. root) to access memory at absolute addresses.

About the video memory, I don't know very much. I think the user who uses a certain console *should* have direct access to its video memory, but I don't know if this is so. (Either this or accessing the ports is the reason why svgalib programs need root privileges.)

If this wasn't quite correct/complete, plase someone correct me.