It also provides an interface to userland through the special files
/dev/mem
and
/dev/kmem
.
Physical memory is accessed through
/dev/mem
,
while kernel virtual memory is accessed through
/dev/kmem
.
Access to kernel virtual addresses not currently mapped to memory will fail.
On hp700, the physical memory range is always contiguous and starts at
address 0; kernel virtual memory begins at address 0 as well.
The writeability of the
/dev/mem
and
/dev/kmem
special files are controlled by the system securelevel in addition to the
filesystem permissions.
/dev/mem
/dev/kmem