[Novalug] 64bit vs 32bit

[Ivan]

Matthew Thompson wrote:
> The heavens stretched forth and Ivan decreed the following on or about 
> 04/08/2008 11:17 AM:
>> In order to determine whether or not you can run a 64bit OS on a 
>> certain CPU, look for the following:
>>
>> $ cat /proc/cpuinfo | grep flags
>> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr 
>> pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext 
>> ~~~~lm~~~~~ 3dnowext 3dnow rep_good
>> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr 
>> pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext 
>> ~~~~lm~~~~~ 3dnowext 3dnow rep_good
>>
>> "lm" - Long mode, indicates the CPU is 64 bit capable.
>
> I have to ask: Is there a manpage or something that decodes all these 
> flags?  Mine is/are:
>
> > cat /proc/cpuinfo | grep flags
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
> mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe 
> syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor 
> ds_cpl vmx est tm2 ssse3 cx16 xtpr dca lahf_lm
> <snip 7 more>
>
> And I can work out a few of these--usually the first ones, since 
> they've been around forever)--but most are just a jumble.
>
> Thanks,
> Matt
According to this site, the docs are the source code:

http://www.linuxforums.org/forum/misc/59157-cpuinfo-flags.html

Specifically - '/usr/include/asm/cpufeature.h'

- Ivan