[PATCH] efi/arm64: efistub: don't abort if base of DRAM is occupied
leif.lindholm at linaro.org
Tue Jul 15 07:49:44 PDT 2014
On Tue, Jul 15, 2014 at 10:23:26AM -0400, Mark Salter wrote:
> On Tue, 2014-07-15 at 14:54 +0100, Leif Lindholm wrote:
> > On Tue, Jul 15, 2014 at 09:11:00AM -0400, Mark Salter wrote:
> > > On Tue, 2014-07-15 at 11:02 +0100, Leif Lindholm wrote:
> > > > > @@ -273,6 +282,10 @@ static void __init free_boot_services(void)
> > > > > continue;
> > > > > }
> > > > >
> > > > > + /* Don't free anything below kernel */
> > > > > + if (md->phys_addr < PHYS_OFFSET)
> > > > > + continue;
> > > > > +
> > > >
> > > > Is the spin table area really allocated as BOOT_SERVICES_*?
> > >
> > > No. It is EFI_RESERVED_TYPE. But if UEFI is allowed below the kernel,
> > > then there could be BS code/data memory which we'd want to ignore.
> > Well, if it is boot service code/data - then there is no need for us
> > to keep it around after ExitBootServices().
> One would think, but EFI has proven to be less than strictly compliant
> in that regard in the past. I'm inclined to keep the boot services
> around until after SetVirtualAddressMap just in case.
But the function you add this clause to will still throw away all boot
services code/data regions - just with this modification it skips
those that happen to lie lower in the address space than the kernel.
(And I do agree with Mark R here - let's not work around bugs that
don't exist yet.)
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