Byte addresses in mem are interpreted as physical memory addresses. References to non-existent locations cause errors to be returned.
Examining and patching is likely to lead to unexpected results when read-only or write-only bits are present.
It is typically created by:
mknod -m 660 /dev/mem c 1 1
chown root.mem /dev/mem
The file kmem is the same as mem, except that the kernel virtual memory rather than physical memory is accessed.
It is typically created by:
mknod -m 640 /dev/kmem c 1 2
chown root.mem /dev/kmem
Port is similar to mem, but the IO ports are accessed.
It is typically created by:
mknod -m 660 /dev/port c 1 4
chown root.mem /dev/port