linux-mips
[Top] [All Lists]

Re: [U-Boot] MIPS UHI spec

To: Paul Burton <paul.burton@imgtec.com>
Subject: Re: [U-Boot] MIPS UHI spec
From: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Date: Thu, 26 Feb 2015 13:37:28 +0100
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>, "u-boot@lists.denx.de" <u-boot@lists.denx.de>, Andrew Bresticker <abrestic@chromium.org>, Ezequiel Garcia <ezequiel.garcia@imgtec.com>, James Hartley <james.hartley@imgtec.com>, James Hogan <james.hogan@imgtec.com>, John Crispin <blogic@openwrt.org>, Jonas Gorski <jogo@openwrt.org>, Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=VRbQR9zXB3q1mVRGkPlFrP7fb2eeMRiQ1Nk9v3aQ8Wc=; b=MOc6kLHd83tyWBUyCgPeW3LfVXFVSjRmA3ZZk2PgL+pgeJKaIFvljK/4p8DOs9G0Cc GD86/ufI20E85wsBmRMM++JqSHeYU9QdTqS8R3AAgP9kaR4hApMuRi0s+GhfbIWf4ihD ASalrg4/RVdU/eU7l9ezmmcPGMfciHE3eQGQp+Ini5u19GVgIExVXaHIBnnkds4yyutU e/B+q0PyNrYTuxh825Dstg07lA4asGfukC55GnPHhmee1l8klQgrQ62iPnTRPSU/KBe3 fFLiJzsO0iDYdTcKVtH7KCQ9R/qAM+KMYZOUDJYC02ulqgt8m++2OcYuUrOscC6gidSv H7gQ==
In-reply-to: <20150226101739.GY17695@NP-P-BURTON>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <6D39441BF12EF246A7ABCE6654B0235320FDC2AC@LEMAIL01.le.imgtec.org> <20150226101739.GY17695@NP-P-BURTON>
Sender: linux-mips-bounce@linux-mips.org
2015-02-26 11:17 GMT+01:00 Paul Burton <paul.burton@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.

U-Boot mainline code is almost ready for DT handover. I have prepared
a patch [1] which completes it by implementing my proposal.

[1] 
http://git.denx.de/?p=u-boot/u-boot-mips.git;a=commitdiff;h=3464e8de491c640d14d72853a741cc367ebabc79

-- 
- Daniel

<Prev in Thread] Current Thread [Next in Thread>