This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[XenPPC] Re: [RFC] consolidated libdt proposal

To: Hollis Blanchard <hollisb@xxxxxxxxxx>
Subject: [XenPPC] Re: [RFC] consolidated libdt proposal
From: Haren Myneni <haren@xxxxxxxxxx>
Date: Mon, 07 Aug 2006 22:37:19 -0700
Cc: "Mark A. Greer" <mgreer@xxxxxxxxxx>, Pantelis Antoniou <pantelis@xxxxxxxxxxxxxxxxx>, "xen-ppc-devel@xxxxxxxxxxxxxxxxxxx" <xen-ppc-devel@xxxxxxxxxxxxxxxxxxx>, Milton Miller <miltonm@xxxxxxx>, linuxppc-dev@xxxxxxxxxx, "Sachin P. Sant" <sachinp@xxxxxxxxxx>, linuxppc-embedded <linuxppc-embedded@xxxxxxxxxx>, Jon Loeliger <jdl@xxxxxxxxxxxxx>
Delivery-date: Mon, 07 Aug 2006 22:38:01 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <1154987921.24455.32.camel@xxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-ppc-devel-request@lists.xensource.com?subject=help>
List-id: Xen PPC development <xen-ppc-devel.lists.xensource.com>
List-post: <mailto:xen-ppc-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ppc-devel>, <mailto:xen-ppc-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ppc-devel>, <mailto:xen-ppc-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20060719230544.GD3887@xxxxxxxxxxxxxxxxx> <1154911082.27074.104.camel@diesel> <1154987921.24455.32.camel@xxxxxxxxxxxxxxxxxxxxx>
Sender: xen-ppc-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050513 Fedora/1.7.8-2
Hollis Blanchard wrote:

On Sun, 2006-08-06 at 19:38 -0500, Hollis Blanchard wrote:
Hmm, so we'll have at least three copies of this code: uboot, kernel,
and Xen. Would it make sense to put this stuff into a libdt.a?
Technically, dtc has a "libdt" already, but it's absurdly incomplete
(I don't even know why it's there), so we could just replace it.

Mark, I had a look at the code Pantelis wrote for u-boot, and it was
pretty easy to adapt to meet Xen's (userspace-based) needs. I've
attached my version below (and see ft_setup() at the bottom of the
file). Does it meet your requirements for the kernel bootwrapper?

One limitation of the attached code is that it doesn't support changing
the *size* of properties, though I don't think that would be too
difficult to add if needed.

Haren, what about using this in kexec-tools?

Good idea to have this lib. Based on brief look, some of these funcs are also useful for kexec-tools. Yes, as you mentioned, changing the size of properties is important for kexec/kdump.

Present flattened device-tree process in kexec-tools:

- Kexec-tool reads the /proc/device-tree and sort these entries since we get the different order than the first kernel uses. - creates linux,usable-memory property under /proc/device-tree/memory@* as appropriate. (for kdump)
- Modify the reserve map for RTAS, initrd, TCE and (0- crashkernel-start)
- Create initrd properties if not exist in the first kernel as needed
- Modify bootargs property


If everybody can use this (I expect small modifications would be
needed), I think we should turn it into a library in the dtc source
tree. The various projects using it could then include snapshots (to
avoid dependencies). In general I'd like to avoid everybody writing and
maintaining their own version of this stuff (myself included).



Xen-ppc-devel mailing list