.TH CPUID 8
.SH NAME
cpuid \- x86 cpuid instriction
.SH SYNOPSIS
.B cpuid
[
.B -w
.I mach
] [-efisvt] [-n fn]
...
.SH DESCRIPTION
.I
Cpuid
prints out information gleaned from the
Intel
.B CPUID
instruction.  A function number may be
specified with the
.B -n
flag.  Alternatively, a few known functions
are available
.TF "-xx "
.PD
.TP
.B "-e"
decode extended feature information from function
0x80000001.
.TP
.B "-f"
decode feature information from function 1.
.TP
.B "-i"
print the informational brand string gathered
from functions 0x80000002-6.
.TP
.B "-s"
print the processor signature returned in AX
from function 0x01 in raw form and also as
.IR family . model . stepping .
.TP
.B "-v"
print the manufacturer's identification string
returned by function 0x00.
.TP
.B "-t"
Intel only?  print the X2APIC processor topology.  
.PP
.SH
EXAMPLE
.IP
.EX
chula; aux/cpuid -t
thread	00000001 00000002 00000100 00000000
core  	00000004 00000008 00000201 00000000
mach0	apic 00000000
mach1	apic 00000002
mach2	apic 00000004
mach3	apic 00000006
4 machs inactive
.EE
.SH SOURCE
.B /sys/src/cmd/aux/cpuid
.SH BUGS
Functions are architecture and vendor specific.