lkml.org 
[lkml]   [2008]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH -mm] kexec jump -v9
From
Date
On Thu, 2008-05-15 at 21:51 -0400, Vivek Goyal wrote:
> On Fri, May 16, 2008 at 09:48:34AM +0800, Huang, Ying wrote:
> > On Thu, 2008-05-15 at 16:09 -0400, Vivek Goyal wrote:
> > [...]
> > > Ok, You want to make BIOS calls. We already do that using vm86 mode and
> > > use bios real mode interrupts. So why do we need this interface? Or, IOW,
> > > how is this interface better?
> >
> > It can call code in 32-bit physical mode in addition to real mode. So It
> > can be used to call EFI runtime service, especially call EFI 64 runtime
> > service under 32-bit kernel or vice versa.
> >
> > The main purpose of kexec jump is for hibernation. But I think if the
> > effort is small, why not support general 32-bit physical mode code call
> > at same time.
> >
>
> In general what's the environment requirements for EFI runtime
> services? I mean, just that processor should be in protected mode with
> paging disabled or one need to stop all other cpus and devices and then make
> the call (as we are doing in this case?).

Put processor in protected mode with paging disabled is sufficient. In
one of previous kexec jump versions, I provide some option to choose the
state saved (whether stop other cpus, whether stop devices).

I agree that now we should focus on kexec based hibernation. But I think
it is reasonable to keep the possibility with minimal effort.

Best Regards,
Huang Ying



\
 
 \ /
  Last update: 2008-05-16 04:05    [W:0.090 / U:0.944 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site