[U-Boot] MIPS UHI spec

[Andrew Bresticker]

Hi Daniel,

On Thu, Feb 26, 2015 at 4:37 AM, Daniel Schwierzeck
<daniel.schwierzeck at gmail.com> wrote:
> 2015-02-26 11:17 GMT+01:00 Paul Burton <paul.burton at imgtec.com>:
>> On Thu, Feb 19, 2015 at 01:50:23PM +0000, Matthew Fortune wrote:
>>> Hi Daniel,
>>>
>>> The spec for MIPS Unified Hosting Interface is available here:
>>>
>>> http://prplfoundation.org/wiki/MIPS_documentation
>>>
>>> As we have previously discussed, this is an ideal place to
>>> define the handover of device tree data from bootloader to
>>> kernel. Using a0 == -2 and defining which register(s) you
>>> need for the actual data will fit nicely. I'll happily
>>> include whatever is decided into the next version of the spec.
>
> this originates from an off-list discussion some months ago started by
> John Crispin.
>
> (CC +John, Ralf, Jonas, linux-mips)
>
>>
>> (CC +Andrew, Ezequiel, James, James)
>>
>> On the talk of DT handover, this recent patchset adding support for a
>> system doing so to Linux is relevant:
>>
>>     http://www.linux-mips.org/archives/linux-mips/2015-02/msg00312.html
>>
>> I'm also working on a system for which I'll need to implement DT
>> handover very soon. It would be very nice if we could agree on some
>> standard way of doing so (and eventually if the code on the Linux side
>> can be generic enough to allow a multiplatform kernel).
>>
>
> to be conformant with UHI I propose $a0 == -2 and $a1 == address of DT
> blob. It is a simple extension and should not interfere with the
> various legacy boot interfaces.

Just to be clear, is $a1 expected to be the physical or virtual
(KSEG0) address of the DTB?

Thanks,
Andrew