[yocto] should YP docs explain "type=kmeta" and "destsuffix="?

[Robert P. J. Day]

On Wed, 4 Mar 2015, Bruce Ashfield wrote:

> On 15-03-04 10:10 AM, Robert P. J. Day wrote:
> >
> >    i see that the meta-xilinx layer takes advantage of extending the
> > search path for features directories with things like:
> >
> > SRC_URI = " \
> > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git;protocol=https;branch=${KBRANCH}
> > \
> > file://xilinx-base;type=kmeta;destsuffix=xilinx-base \
> > file://0001-ARM64-Add-new-Xilinx-ZynqMP-SoC.patch \
> >    ... etc etc ...
> >
> > and the above is processed from kernel-yocto.bbclass with:
> >
> > # check the SRC_URI for "kmeta" type'd git repositories. Return the name of
> > # the repository as it will be found in WORKDIR
> > def find_kernel_feature_dirs(d):
> >      feature_dirs=[]
> >      fetch = bb.fetch2.Fetch([], d)
> >      for url in fetch.urls:
> >          urldata = fetch.ud[url]
> >          parm = urldata.parm
> >          if "type" in parm:
> >              type = parm["type"]
> >          if "destsuffix" in parm:
> >              destdir = parm["destsuffix"]
> >              if type == "kmeta":
> >                  feature_dirs.append(destdir)
> >
> >      return feature_dirs
> >
> > i see no mention of this feature in any of the YP docs ... is it meant
> > to be used by normal developers, so that it should be explained?
>
> It's not really a typical developer option. It is for maintaining a
> separate repository of meta-data, and then allowing the tools and
> kernel to use that meta data as part of the build.
>
> Only someone maintaining (and sharing) a large set of their own
> kernel fragments would be interested in this.
>
> So I'm on the fence if it is worth documenting, but lean towards at
> least mentioning it and offering a simple use case.

  if it's not a normal developer option, then i wouldn't want it to be
presented as *regular* kernel dev content, so as not to break up the
flow of presentation -- one of my pet peeves in documentation is
distraction from normal content with a topic that's obscure or meant
for only 1 per cent of the readership, that just throws off the rhythm
of the presentation.

  however, it might fit in a section on, say, "advanced kernel
workflow concepts", or something like that. appendix, perhaps?

  also, i only ask about this as i tripped across it perusing the
meta-xilinx layer, and thought, "wait a minute, what's this?" but
nothing says that it's being used properly in the meta-xilinx layer
... i think it's worth documenting but only if it's accompanied by a
use case that clearly shows its value over the standard technique
involving regular .cfg and .scc files.

  anyway, movin' on ...

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================