Document /dev/{k,}mem as usual, as well as the mem0 attachment flags and why

one might want to use them; mdoc tweaks jmc, feedback from mickey as well.

2 files changed, 90 insertions, 2 deletions

diff --git a/share/man/man4/man4.hppa/Makefile b/share/man/man4/man4.hppa/Makefile
index 2d69812c9b1..45ab7ce9d35 100644
--- a/share/man/man4/man4.hppa/Makefile
+++ b/share/man/man4/man4.hppa/Makefile
@@ -1,8 +1,9 @@
-#	$OpenBSD: Makefile,v 1.16 2004/01/15 14:15:00 mickey Exp $
+#	$OpenBSD: Makefile,v 1.17 2004/03/17 00:42:43 miod Exp $
 
 MAN=	asp.4 cpu.4tbl dino.4 gsc.4 gsckbc.4 gsckbd.4 harmony.4 ie.4 
-MAN+=	intro.4 io.4 lasi.4 phantomas.4 power.4 wax.4
+MAN+=	intro.4 io.4 lasi.4 mem.4 phantomas.4 power.4 wax.4
 # mongoose.4 tir.4 xbar.4 mcx.4
+MLINKS+= mem.4 kmem.4
 MANSUBDIR=hppa
 
 .include <bsd.prog.mk>
diff --git a/share/man/man4/man4.hppa/mem.4 b/share/man/man4/man4.hppa/mem.4
new file mode 100644
index 00000000000..61358177924
--- /dev/null
+++ b/share/man/man4/man4.hppa/mem.4
@@ -0,0 +1,87 @@
+.\"	$OpenBSD: mem.4,v 1.1 2004/03/17 00:42:43 miod Exp $
+.\"
+.\" Copyright (c) 2004, Miodrag Vallat.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+.\" DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd March 16, 2004
+.Dt MEM 4 hppa
+.Os
+.Sh NAME
+.Nm mem ,
+.Nm kmem
+.Nd memory files and memory controller
+.Sh SYNOPSIS
+.Cd "mem* at mainbus0 flags 0x0000"
+.Sh DESCRIPTION
+The
+.Nm
+driver controls and restricts access to the systems memory
+by the hardware buses and the processor.
+.Pp
+It also provides an interface to userland through the special files
+.Pa /dev/mem
+and
+.Pa /dev/kmem .
+Physical memory is accessed through
+.Pa /dev/mem ,
+while kernel virtual memory is accessed through
+.Pa /dev/kmem .
+Access to kernel virtual addresses not currently mapped to memory will fail.
+On hppa, the physical memory range is always contiguous and starts at
+address 0; kernel virtual memory begins at address 0 as well.
+.Pp
+The writeability of the
+.Pa /dev/mem
+and
+.Pa /dev/kmem
+special files are controlled by the system
+.Xr securelevel 7 ,
+in addition to the filesystem permissions.
+.Sh FILES
+.Bl -tag -width /dev/kmem -compact
+.It Pa /dev/mem
+.It Pa /dev/kmem
+.El
+.Sh SEE ALSO
+.Xr securelevel 7
+.Sh CAVEATS
+On some systems featuring a
+.Dq Viper
+memory controller,
+.Ox
+may not configure bus arbitration correctly, causing the boot process
+to freeze during either
+.Nm
+or
+.Xr cpu 4
+device probe.
+.Pp
+In this case, a different initialization strategy can be achieved by
+setting
+.Ar flags
+to 0x0001
+.Po
+see
+.Xr boot_config 8
+for details
+.Pc .