[U-Boot] [PATCH] pxe: implement fdtdir extlinux.conf tag

[Dennis Gilmore]

El Fri, 24 Jan 2014 10:20:16 -0700
Stephen Warren <swarren at wwwdotorg.org> escribió:
> On 01/24/2014 09:15 AM, Tom Rini wrote:
> > On Thu, Jan 23, 2014 at 12:55:27PM -0700, Stephen Warren wrote:
> >> From: Stephen Warren <swarren at nvidia.com>
> >>
> >> People who write (or scripts that auto-generate) extlinux.conf
> >> don't want to know about HW-specific information such as FDT
> >> filenames. Create a new extlinux.conf tag "fdtdir" that specifies
> >> only the directory where FDT files are located, and defer all
> >> knowledge of the filename to U-Boot. The algorithm implemented is:
> ...
> >> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> > 
> > My only real concern is that
> > http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/ is as
> > best I can see the spec for extlinux.conf and it doesn't talk about
> > this tag.  So while it sounds like a good idea, if we implement it
> > and it's not documented outside of U-Boot, will anyone use it?
> 
> Well, Dennis is actively working on making Fedora support
> extlinux.conf for at least ARM, and said on IRC that he was going to
> patch the Fedora generator to use it, so yes:-)

the tag is going to be added to the spec. we still have a little more
work to do to fully support the spec. At the least version and
machine-id tags and being able to dynamically find the .conf files. It
is also safe to add additional tags as needed.

> Dennis, should you or I simply edit that wiki, or is there some other
> process for changing it?
I spoke with Harald Hoyer just now and he said he would edit the spec

> Related, I notice that it documents a "devicetree" tag, whereas U-Boot
> (prior to my patches) actually implements an "fdt" tag for the same
> purpose...

he also said 
18:12 < haraldh> dgilmore, go with "fdt" and "fdtdir"

since u-boot has existing support out there for fdt for the same
purpose.

Dennis