[PATCH 05/10] arm64: Convert dts to use reserved-memory nodes

Grant Likely grant.likely at linaro.org
Tue Nov 4 03:37:30 PST 2014


On Mon, Nov 3, 2014 at 10:26 PM, Rob Herring <robherring2 at gmail.com> wrote:
> On Fri, Oct 31, 2014 at 6:44 PM, Geoff Levand <geoff at infradead.org> wrote:
>> On Fri, 2014-10-24 at 13:27 +0100, Mark Rutland wrote:
>> Current user space kexec utilities use /proc/device-tree and nothing
>> else.  The intension of the device tree is to describe the system
>> sufficiently for a kernel to boot, so I think we should put the
>> /memreserve/ info into /proc/device-tree.
>>
>> We could put the /memreserve/ entries in there directly, or convert
>> to reserved-memory nodes.  At the moment I like the idea to convert to
>> reserved-memory nodes.
>
> I'm just wondering does UEFI being used for the memory information
> have any impact here as the DT would not have valid memory nodes
> either? I'd assume reserved memory comes from UEFI (or both) in that
> case?

It should, but as always the answer is not simple. UEFI+DT, it may be
that a CMA region is specified in /reserved-memory and we would want
to respect that, even when getting memory information from UEFI.

However, the /memreserve/ section shouldn't be an issue in this case.
Anything firmware needs protected must be reflected in the UEFI memory
map.

g.



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