Re: [Xen-devel] [PATCH] x86/boot: Use mov to cr0 in preference to lmsw

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 28/08/13 11:22, Jan Beulich wrote:
>>>> On 28.08.13 at 12:05, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
>> lmsw is for compability for 286 processors only, and any more modern
>> processors are recomended to use mov to cr0.  Xen has never been capable of
>> booting on a 286, given its multiboot entry.
> I don't really mind this part (albeit it results in growth of the
> trampoline code), but ...
>
>> Furthermore, this avoids needless playing with the CD, NW and AM bits.  
>> These do get explicitly chosen slightly later on boot.
> ... I clearly don't understand what you're referring to here: These
> bits don't get modified by LMSW.
>
> Jan
>

D'oh - yes. I intended the MP, EM and TS bits. (I scanned the wrong
direction through the written description of the cr0 bits).  The

I shall send v2 which corrects the description - it is a bit too
misleading as it currently stands.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel