1.\" Copyright (c) 1999 Chris Costello
2.\" All rights reserved.
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25.\" $FreeBSD: src/usr.sbin/memcontrol/memcontrol.8,v 1.3.2.5 2003/03/12 22:08:15 trhodes Exp $
26.\" $DragonFly: src/usr.sbin/memcontrol/memcontrol.8,v 1.2 2003/06/17 04:29:57 dillon Exp $
27.\"
28.Dd September 28, 1999
29.Dt MEMCONTROL 8
30.Os
31.Sh NAME
32.Nm memcontrol
33.Nd "control system cache behaviour with respect to memory"
34.Sh SYNOPSIS
35.Nm
36.Cm list
37.Op Fl a
38.Nm
39.Cm set
40.Fl b Ar base
41.Fl l Ar length
42.Fl o Ar owner
43.Ar attribute
44.Nm
45.Cm clear
46.Fl o Ar owner
47.Nm
48.Cm clear
49.Fl b Ar base
50.Fl l Ar length
51.Sh DESCRIPTION
52A number of supported system architectures allow the behaviour of the CPU
53cache to be programmed to behave differently depending on the region being
54written.
55.Pp
56The
57.Nm
58utility
59provides an interface to this facility, allowing CPU cache behavior to
60be altered for ranges of system physical memory.
61.Pp
62These ranges are typically power-of-2 aligned and sized, however the specific
63rules governing their layout vary between architectures.
64The
65.Nm
66utility does not attempt to enforce these rules, however the system will
67reject any attempt to set an illegal combination.
68.Bl -tag -width ".Cm clear"
69.It Cm list
70List range slots.
71.Bl -tag -width indent
72.It Fl a
73List all range slots, even those that are inactive.
74.El
75.It Cm set
76Set memory range attributes.
77.Bl -tag -width indent
78.It Fl b Ar base
79Memory range base address.
80.It Fl l Ar length
81Length of memory range in bytes, power of 2.
82.It Fl o Ar owner
83Text identifier for this setting (7 char max).
84.It Ar attribute
85Attributes applied to this range; combinations of
86.Cm force , uncacheable , write-combine , write-through , write-back ,
87and
88.Cm write-protect .
89.El
90.It Cm clear
91Clear memory range attributes.
92Ranges may be cleared by owner or by
93base/length combination.
94.Pp
95To clear based on ownership:
96.Bl -tag -width indent
97.It Fl o Ar owner
98All ranges with this owner will be cleared.
99.El
100.Pp
101To clear based on the base/length combination:
102.Bl -tag -width indent
103.It Fl b Ar base
104Memory range base address.
105.It Fl l Ar length
106Length of memory range in bytes, power of 2.
107.El
108.Pp
109Base and length must exactly match an existing range.
110.El
111.Sh SEE ALSO
112.Xr mem 4
113