[PATCH v3 4/4] kexec, x86_64: Load bzImage64 above 4G

[Yinghai Lu]

On Wed, Nov 21, 2012 at 12:00 PM, Vivek Goyal <vgoyal at redhat.com> wrote:
> On Wed, Nov 21, 2012 at 11:50:56AM -0800, Yinghai Lu wrote:
>
> [..]
>> > So how do I force a 16bit or 32bit entry using a bzImage64?
>>
>> kexec -t bzImage -l ....
>> will load low and use 32bit entry.
>>
>
> Ok, so user needs to enforce image type (using -t option) to bzImage
> (for a bzImage which supports 64bit entry point) to be able to use
> 32bit entry.
>
> I think a better option is that bzImage64 loader parses the user specified
> entry options and call into 32bit bzImage loader if user is asking for 32bit
> or 16bit entry. For 16bit, we already have option --real-mode option. May
> be we need to introduce another one for forcing 32bit entry, say --entry-32bit
> or --protected-mode (whatever makes sense).

that is doable.

add checking entry-32bit and real-mode checking in kexec-bzImage64.c
and bail early to leave kexec-bzImage.c to take over.