[PATCH 06/10] arm64: Update booting.txt to reserved-memory nodes

[Grant Likely]

On Fri, Oct 24, 2014 at 1:18 PM, Mark Rutland <mark.rutland at arm.com> wrote:
> On Fri, Oct 24, 2014 at 12:04:00PM +0100, Grant Likely wrote:
>> On Fri, Oct 24, 2014 at 11:54 AM, Mark Rutland <mark.rutland at arm.com> wrote:
>> >
>> > On Fri, Oct 24, 2014 at 12:10:58AM +0100, Geoff Levand wrote:
>> > > Change any reference of device tree '/memreserve/' entries in the arm64
>> > > booting.txt to refer to 'reserved-memory nodes'.  Reserved-memory nodes
>> > > are the preferred method of specifying reserved memory.
>> >
>> > Per my comments on patch 5, I don't think this change is sufficient.
>> >
>> > However, we should probably update the document to allow reserved-memory
>> > nodes.
>> >
>> > On an unrelated note we probably need to work out how reserved-memory
>> > interacts with the UEFI memory map -- unmappable regions shouldn't be
>> > described by UEFI and I hope people don't use reserved-memory as a
>> > workaround for broken UEFI tables.
>>
>>
>> When booting with UEFI, the boot stub will clear out all memory nodes
>> and (should) clear out reserved regions so that the kernel can use the
>> UEFI memory map as authoritative.
>
> We clear memory nodes and memreserves currently.
>
> I was thinking about reserved-memory nodes (for CMA and such), which we
> don't currently clear.

We should either clear them, or make sure that they will coexist
happily with the UEFI map. I can think of a few situations, like CMA,
where still having the reserved-memory node would be a good idea.

g.