freebsd man page for cpucontrol

CPUCONTROL(8)						    BSD System Manager's Manual 					     CPUCONTROL(8)

NAME
     cpucontrol -- control utility for the cpuctl(4) device

SYNOPSIS
     cpucontrol [-vh] -m msr device
     cpucontrol [-vh] -m msr=value device
     cpucontrol [-vh] -m msr&=mask device
     cpucontrol [-vh] -m msr|=mask device
     cpucontrol [-vh] -i level device
     cpucontrol [-vh] -i level,level_type device
     cpucontrol [-vh] [-d datadir] -u device

DESCRIPTION
     The cpucontrol utility can be used to read and write arbitrary machine-specific CPU registers via the cpuctl(4) special device.  It can also
     be used to apply CPU firmware updates.

     The following options are available:

     -d datadir
	     Where to look for microcode images.  The option can be specified multiple times.

     -m msr[=value]
	     Show value of the specified MSR.  MSR register number should be given as a hexadecimal number.

     -m msr=value
	     Store the value in the specified MSR register.  The value argument can be prefixed with ~ operator.  In this case the inverted value
	     of argument will be stored in the register.

     -m msr&=mask
	     Store the result of bitwise AND operation between mask and the current MSR value in the MSR register.  The mask argument can be pre-
	     fixed with ~ operator.  In this case the inverted value of mask will be used.

     -m msr|=mask
	     Store the result of bitwise OR operation between mask and the current MSR value in the MSR register.  The mask argument can be pre-
	     fixed with ~ operator.  In this case the inverted value of mask will be used.

     -i level
	     Retrieve CPUID info.  Level should be given as a hex number.

     -i level,level_type
	     Retrieve CPUID info.  Level and level_type should be given as hex numbers.

     -u      Apply CPU firmware updates.  The cpucontrol utility will walk through the configured data directories and apply all firmware updates
	     available for this CPU.

     -v      Increase the verbosity level.

     -h      Show help message.

EXIT STATUS
     The cpucontrol utility exits 0 on success, and >0 if an error occurs.

EXAMPLES
     The command

     ``cpucontrol -m 0x10 /dev/cpuctl0''

     will read the contents of TSC MSR from CPU 0.

     To set the CPU 0 TSC MSR register value to 0x1 issue

     ``cpucontrol -m 0x10=0x1 /dev/cpuctl0''.

     The following command will clear the second bit of TSC register:

     ``cpucontrol -m 0x10&=~0x02 /dev/cpuctl0''.

     The following command will set the forth and second bit of TSC register:

     ``cpucontrol -m 0x10|=0x0a /dev/cpuctl0''.

     The command

     ``cpucontrol -i 0x1 /dev/cpuctl1''

     will retrieve the CPUID level 0x1 from CPU 1.

     To perform firmware updates on CPU 0 from images located at /usr/local/share/cpuctl/ use the following command:

     ``cpucontrol -d /usr/local/share/cpuctl/ -u /dev/cpuctl0''

SEE ALSO
     cpuctl(4)

HISTORY
     The cpucontrol utility first appeared in FreeBSD 7.2.

AUTHORS
     The cpucontrol utility and this manual page was written by Stanislav Sedov <stas@FreeBSD.org>.

BUGS
     Yes, probably, report if any.

BSD
								   June 30, 2009							       BSD