arm/arm64 UEFI boot protocol

[Grant Likely]

On Wed, Nov 13, 2013 at 3:00 AM, Leif Lindholm <leif.lindholm at linaro.org> wrote:
> On Tue, Nov 12, 2013 at 04:42:41PM +0000, Will Deacon wrote:
>> > ______________________________________________________________________________
>> > Name                      | Size   | Description
>> > ================================================================================
>> > linux,uefi-system-table   | 64-bit | Physical address of the UEFI System Table.
>> > --------------------------------------------------------------------------------
>> > linux,uefi-mmap           | 64-bit | Physical address of the UEFI memory map,
>> >                           |        | populated by the UEFI GetMemoryMap() call.
>> > --------------------------------------------------------------------------------
>> > linux,uefi-mmap-size      | 32-bit | Size in bytes of the UEFI memory map
>> >                           |        | pointed to in previous entry.
>> > --------------------------------------------------------------------------------
>> > linux,uefi-mmap-desc-size | 32-bit | Size in bytes of each entry in the UEFI
>> >                           |        | memory map.
>>
>> Do we actually need to define these sizes here, or can they be dealt with
>> using the usual #address-cells property? Also, I think you should describe
>> the binding in a separate document somewhere under Documentation/devicetree,
>> then cross-reference it from here.
>
> This is not a generic ABI, so I don't think it belongs in there (it will
> never be in a .dtb, and the only way it can be generated by something
> that isn't the stub is by lying).
> But I don't really care either way - as long as some general agreement
> can be had.

There is precedence with inserting the initrd location into the kernel
with similar properties. I think the binding does the right thing
here.

In the interest of bike shedding, I would name the properties
"linux,uefi-mmap-start" and "linux,uefi-mmap-size", but otherwise it
is fine by me. Should you have a property for the descriptor version
as returned by GetMemoryMap()?

>
>> > --------------------------------------------------------------------------------
>> > linux,uefi-stub-kern-ver  | string | Copy of linux_banner from build.
>> > --------------------------------------------------------------------------------
>>
>> Are you sure you want to refer to kernel symbols here? If somebody renames
>> that variable, they're not going to fix this file.
>
> There is a comment above the definition of linux_banner that says:
> /* FIXED STRINGS! Don't touch! */
>
> Sounded reliable enough to me :)

I think this is just fine.

g.