MEM(4)                NetBSD/x86 Kernel Interfaces Manual               MEM(4)

NAME
     mem, kmem -- memory files

DESCRIPTION
     The special file /dev/mem is an interface to the physical memory of the
     computer.  Byte offsets in this file are interpreted as physical memory
     addresses.  Reading and writing this file is equivalent to reading and
     writing memory itself.  Only offsets within the bounds of /dev/mem are
     allowed.

     Kernel virtual memory is accessed through the interface /dev/kmem in the
     same manner as /dev/mem.  Only kernel virtual addresses that are cur-
     rently mapped to memory are allowed.

     On ISA the I/O memory space begins at physical address 0x000a0000 and
     runs to 0x00100000.  The per-process data size for the current process is
     UPAGES long, and ends at virtual address 0xfe000000.

FILES
     /dev/mem
     /dev/kmem

HISTORY
     The mem, kmem files appeared in Version 6 AT&T UNIX.

NetBSD 6.0                    September 23, 2011                    NetBSD 6.0