1.\" Copyright (c) 1992, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This software was developed by the Computer Systems Engineering group 5.\" at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 6.\" contributed to Berkeley. 7.\" 8.\" %sccs.include.redist.man% 9.\" 10.\" @(#)mem.4 8.1 (Berkeley) 06/05/93 11.\" 12.Dd 13.Dt MEM 4 sparc 14.Os 15.Sh NAME 16.Nm mem , 17.Nm kmem 18.Nd main memory 19.Sh DESCRIPTION 20The file 21.Nm /dev/mem 22is an interface to the physical memory of the 23computer. 24Byte offsets in this file are interpreted as physical memory addresses. 25Reading and writing this file is equivalent to reading and writing 26memory itself. 27An error will be returned if an attempt is made to reference 28an offset outside of 29.Nm /dev/mem . 30.Pp 31Kernel virtual memory is accessed via the file 32.Nm /dev/kmem 33in the same manner as 34.Nm /dev/mem . 35Only kernel virtual addresses that are currently mapped to memory are allowed. 36.Sh SPARC 37On the 38.Tn SPARC , 39physical memory may be discontiguous; 40kernel virtual memory begins at 41.Li 0xf8000000 . 42.Sh FILES 43.Bl -tag -width /dev/kmem -compact 44.It Pa /dev/mem 45.It Pa /dev/kmem 46.El 47.Sh HISTORY 48The files 49.Nm mem 50and 51.Nm kmem 52appeared in 53.At v6 . 54