xref: /freebsd/usr.sbin/cpucontrol/cpucontrol.8 (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1.\" Copyright (c) 2006, 2008 Stanislav Sedov <stas@FreeBSD.org>.
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25.Dd January 5, 2018
26.Dt CPUCONTROL 8
27.Os
28.Sh NAME
29.Nm cpucontrol
30.Nd control utility for the
31.Xr cpuctl 4
32device
33.Sh SYNOPSIS
34.Bk
35.Nm
36.Op Fl v
37.Fl m Ar msr
38.Ar device
39.Ek
40.Bk
41.Nm
42.Op Fl v
43.Fl m Ar msr Ns = Ns Ar value
44.Ar device
45.Ek
46.Bk
47.Nm
48.Op Fl v
49.Fl m Ar msr Ns &= Ns Ar mask
50.Ar device
51.Ek
52.Bk
53.Nm
54.Op Fl v
55.Fl m Ar msr Ns |= Ns Ar mask
56.Ar device
57.Ek
58.Bk
59.Nm
60.Op Fl v
61.Fl i Ar level
62.Ar device
63.Ek
64.Bk
65.Nm
66.Op Fl v
67.Fl i Ar level,level_type
68.Ar device
69.Ek
70.Bk
71.Nm
72.Op Fl vn
73.Op Fl d Ar datadir
74.Fl u
75.Ar device
76.Ek
77.Bk
78.Nm
79.Fl e
80.Ar device
81.Ek
82.Sh DESCRIPTION
83The
84.Nm
85utility can be used to read and write arbitrary machine-specific
86CPU registers via the
87.Xr cpuctl 4
88special device.
89It can also be used to apply CPU firmware updates.
90.Pp
91The following options are available:
92.Bl -tag -width indent
93.It Fl d Ar datadir
94Directory paths where to look for microcode images.
95The option can be specified multiple times.
96The paths are added in order of the options appearance on the command
97line, default directories are appended after the user-supplied paths.
98.It Fl n
99Do not look for the microcode images in the standard directories.
100Currently standard directory to look for the microcode update files is
101.Pa /usr/local/share/cpucontrol .
102.It Fl m Ar msr
103Show value of the specified MSR.
104MSR register number should be given as a hexadecimal number.
105The high word is printed first, then the low word is printed second.
106.It Fl m Ar msr Ns = Ns Ar value
107Store the
108.Ar value
109in the specified MSR register.
110The
111.Ar value
112argument can be prefixed with ~ operator.
113In this case the inverted value of argument will be stored in the register.
114.It Fl m Ar msr Ns &= Ns Ar mask
115Store the result of bitwise AND operation between
116.Ar mask
117and the current MSR value in the MSR register.
118The
119.Ar mask
120argument can be prefixed with ~ operator.
121In this case the inverted value of mask will be used.
122.It Fl m Ar msr Ns |= Ns Ar mask
123Store the result of bitwise OR operation between
124.Ar mask
125and the current MSR value in the MSR register.
126The
127.Ar mask
128argument can be prefixed with ~ operator.
129In this case the inverted value of mask will be used.
130.It Fl i Ar level
131Retrieve CPUID info.
132Level should be given as a hex number.
133.It Fl i Ar level,level_type
134Retrieve CPUID info.
135Level and level_type should be given as hex numbers.
136.It Fl u
137Apply CPU firmware updates.
138The
139.Nm
140utility will walk through the configured data directories
141and apply all firmware updates available for this CPU.
142.It Fl e
143Re-evaluate the kernel flags indicating the present CPU features.
144This command is typically executed after a firmware update was applied
145which changes information reported by the
146.Dv CPUID
147instruction.
148.Pp
149.Bf -symbolic
150Only execute the
151.Fl e
152command after the microcode update was applied to all CPUs in the system.
153The kernel does not operate correctly if the features of processors are
154not identical.
155.Ef
156.It Fl v
157Increase the verbosity level.
158.It Fl h
159Show help message.
160.El
161.Sh EXIT STATUS
162.Ex -std
163.Sh EXAMPLES
164The command
165.Pp
166.Dq Li "cpucontrol -m 0x10 /dev/cpuctl0"
167.Pp
168will read the contents of TSC MSR from CPU 0.
169.Pp
170To set the CPU 0 TSC MSR register value to 0x1 issue
171.Pp
172.Dq Li "cpucontrol -m 0x10=0x1 /dev/cpuctl0" .
173.Pp
174The following command will clear the second bit of TSC register:
175.Pp
176.Dq Li "cpucontrol -m 0x10&=~0x02 /dev/cpuctl0" .
177.Pp
178The following command will set the forth and second bit of TSC register:
179.Pp
180.Dq Li "cpucontrol -m 0x10|=0x0a /dev/cpuctl0" .
181.Pp
182The command
183.Pp
184.Dq Li "cpucontrol -i 0x1 /dev/cpuctl1"
185.Pp
186will retrieve the CPUID level 0x1 from CPU 1.
187.Pp
188To perform firmware updates on CPU 0 from images located at
189.Pa /usr/local/share/cpuctl
190use the following command:
191.Pp
192.Dq Li "cpucontrol -nd /usr/local/share/cpuctl -u /dev/cpuctl0"
193.Sh SEE ALSO
194.Xr cpuctl 4
195.Sh HISTORY
196The
197.Nm
198utility first appeared in
199.Fx 7.2 .
200.Sh AUTHORS
201The
202.Nm
203utility and this manual page was written by
204.An Stanislav Sedov Aq Mt stas@FreeBSD.org .
205