[yocto] clarification about BSP layer names and bblayers.conf file?

[Tom Zanussi]

On Fri, 2013-04-19 at 08:37 -0400, Robert P. J. Day wrote:
> from section 1.1 of BSP developers guide:
> 
> http://www.yoctoproject.org/docs/latest/bsp-guide/bsp-guide.html#bsp-layers
> 
> first, it's not actually *required* that a layer name start with the
> prefix "meta-", is it?  pretty sure it's not and, if it isn't, that
> should be made abundantly clear. it's fine to point out that it's a
> well-established convention but it should still be mentioned
> explicitly that it's not necessary.
> 

Right, the naming isn't required and it would make sense to make that
clear, I agree.

>   second, the BBLAYERS example there seems overly complicated and
> potentially confusing to beginners. the fact that meta-yocto is listed
> as NON_REMOVABLE might make readers wonder how they're supposed to
> know that. why not go with something a lot more people will see, like,
> say:
> 
>      BBLAYERS = ?" \                  <-- and that looks like a typo
>        /usr/local/src/yocto/meta \
>        /usr/local/src/yocto/meta-ti \
>        "
> 
>      BBLAYERS_NON_REMOVABLE ?= " \
>        /usr/local/src/yocto/meta \
>        "
> 

I agree - the whole NON_REMOVABLE thing doesn't add anything and should
be removed - the example is just trying to show how to add a BSP layer -
the rest just adds potential confusion.  And, yeah, it's a typo..

>   finally, the passing reference to layers that contain sub-BSP-layers
> is good, but show an example, such as the fact that the meta-crownbay
> layer.conf file has a dependency on meta-intel:
> 
> ...
> LAYERDEPENDS_crownbay = "intel"
> 
>   never pass up the opportunity to reinforce an idea with a few lines
> of actual code. :-)
> 

Agreed, but on the other hand we don't really want to be too
intel-specific (I know, we have crownbay everywhere else, but anyway..)

Tom

>   more shortly ...
> 
> rday
>