GSoC Project: EFI on amd64/i386

John Baldwin jhb at freebsd.org
Tue May 15 17:03:29 UTC 2012


On Tuesday, May 15, 2012 4:00:44 am Michael Reifenberger wrote:
> On Mon, 14 May 2012, Eric McCorkle wrote:
> ...
> > If I understand things correctly, boot2 handles the switch to
> > protected mode (as well as enabling A20), both loader(8) and the
> > kernel begin their execution in a protected mode environment.  Can I
> > get an absolute confirmation on this?  Obviously if this is not the
> > case, then there will need to be another (protected mode) entry point
> > into the kernel.
> >
> 
> No.
> *boot* and *loader should be the same on X32 and AMD64.
> The kernel seems to switch to long mode in /sys/amd64/amd64/mpboot.S

No.  That is only for AP startup.  The loader switches to long mode for an 
amd64 kernel before it starts the kernel.  For i386, boot2 and the loader
both start the kernel while running in flat 32-bit protected mode (so no 
paging).

-- 
John Baldwin


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