1 .\" Copyright (c) 2006-2008 Stanislav Sedov <stas@FreeBSD.org>
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32 .Nd cpuctl pseudo device
34 To compile this driver into the kernel,
35 place the following lines in your kernel
37 .Bd -ragged -offset indent
41 Alternatively, to load the driver as a module
42 at boot time, place the following in
44 .Bd -literal -offset indent
50 presents interface to the system CPU.
51 It provides functionality to retrieve
52 CPUID information, read/write machine specific registers (MSR) and perform
55 For each CPU present in the system, the special device
57 with the appropriate index will be created.
58 For multicore CPUs such a
59 special device will be created for each core.
61 Currently, only i386 and amd64 processors are
64 All of the supported operations are invoked using the
67 Currently, the following ioctls are defined:
68 .Bl -tag -width CPUCTL_CPUID_COUNT
69 .It Dv CPUCTL_RDMSR Fa cpuctl_msr_args_t *args
70 .It Dv CPUCTL_WRMSR Fa cpuctl_msr_args_t *args
71 Read/write CPU machine specific register.
74 structure is defined in
79 int msr; /* MSR to read */
83 .It Dv CPUCTL_MSRSBIT Fa cpuctl_msr_args_t *args
84 .It Dv CPUCTL_MSRCBIT Fa cpuctl_msr_args_t *args
85 Set/clear MSR bits according to the mask given in the
88 .It Dv CPUCTL_CPUID Fa cpuctl_cpuid_args_t *args
89 Retrieve CPUID information.
90 Arguments are supplied in the following structure:
93 int level; /* CPUID level */
95 } cpuctl_cpuid_args_t;
97 It is equivalent to the
98 .Dv CPUCTL_CPUID_COUNT
102 .It Dv CPUCTL_CPUID_COUNT Fa cpuctl_cpuid_count_args_t *args
103 Retrieve CPUID information.
104 Arguments are supplied in the following structure:
107 int level; /* CPUID level */
108 int level_type; /* CPUID level type */
110 } cpuctl_cpuid_count_args_t;
114 field indicates the CPUID level to retrieve,
115 it is loaded into the
117 register before the CPUID instruction is executed,
120 field indicates the CPUID level type to retrieve,
121 it is loaded into the
127 field is used to store the received CPUID data.
130 contains the value of
132 register after the CPUID instruction is executed,
143 .It Dv CPUCTL_UPDATE cpuctl_update_args_t *args
144 Update CPU firmware (microcode).
145 The structure is defined in
152 } cpuctl_update_args_t;
157 field should point to the firmware image of size
161 For additional information refer to
164 .Bl -tag -width /dev/cpuctl -compact
170 The operation requested is not supported by the device (e.g., unsupported
171 architecture or the CPU is disabled).
173 Incorrect request was supplied, or microcode image is not correct.
175 No physical memory was available to complete the request.
177 The firmware image address points outside the process address space.
185 driver first appeared in
190 module and this manual page were written by
191 .An Stanislav Sedov Aq stas@FreeBSD.org .
193 Yes, probably, report if any.