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
currently mapped to memory are allowed.
On Acorn RiscPC, A7000(+) and RC7500 systems the I/O memory space
(podule space and SuperIO) begins at physical address 0x03000000 and runs to
0x033fffff. On the RiscPC, EASI space runs from 0x08000000 to 0x0fffffff.
The per-process data size for the current process is
UPAGES long, and starts at VM_MAXUSER_ADDRESS.
FILES
- /dev/mem
- /dev/kmem
HISTORY
The mem, kmem
files appeared in Version 6 AT&T
UNIX.