[yocto] couple questions about kernel dev manual, section 2

[Tom Zanussi]

On Sat, 2013-04-13 at 11:20 -0400, Robert P. J. Day wrote:
> some oddities in section 2.2.1 of the current kernel dev manual.
> first, there's:
> 
> "The append file should initially contain the following text:
> 
>      FILESEXTRAPATHS := "${THISDIR}/${PN}"
> 
>   i was under the impression that the standard line would be:
> 
>      FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
> 
> would it not? to make sure you can support potential layers on top of
> layers, no?  if you absolutely *know* that won't happen, then, sure,
> that will work, but i think the wording above is unnecessarily
> restrictive.
> 

Right, that should be changed to match the recommendation in the Poky
Reference manual.

>   also, right underneath that, one reads:
> 
> "If you add any new files that modify the kernel recipe, you need to
> place them in your layer in the following area:
> 
>      <your-layer>/recipes-kernel/linux/linux-yocto/"
> 
> IIRC, you *can* put them there but you don't *need* to. in fact, tom
> zanussi's kernel labs place extra files simply under a "files/"
> subdirectory (after setting FILESEXTRAPATHS to pick up that
> directory). so, again, some wording that is unnecessarily strong and
> somewhat misleading.
> 
>   thoughts?
> 

That text assumes you've used (the corrected) from the paragraph above:

FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"

which means you do need to put the files in the linux-yocto/ subdir (for
a linux-yocto bbappend), since we're dealing with a .bbappend here.

If we were talking about a recipe, then yes, we wouldn't *need* to put
them there but could also put them in any of the default subdirs such as
files/.  There's a little more discussion about it here:

https://lists.yoctoproject.org/pipermail/yocto/2013-February/014419.html

Seems like it might be good to explicitly explain all this or at least
point out the difference and help avoid the confusion...

Tom

> rday
>