[yocto] Newbie trying to get started

[McClintock Matthew-B29882]

On Fri, Mar 1, 2013 at 12:20 AM, Paul D. DeRocco <pderocco at ix.netcom.com> wrote:
>> From: McClintock Matthew-B29882
>>
>> Not sure about the Intel BSPs but they may contain just their layer
>> and/or poky + meta-intel. It does not really matter where meta-intel
>> lives on your file system though. It can be referenced directly in
>> your 'conf/bblayers.conf' file in your build folder.
>>
>> > Then, the directions say to edit bblayers.conf, and
>> possibly local.conf. The
>> > only place I find these files are in my yocto/build/conf
>> directory, but I
>> > would think that doing a build for a different machine
>> would involve setting
>> > up a different build directory, e.g., yocto/buildatom. Is
>> that correct? But
>> > isn't the build directory set up by running the
>> oe-init-build-env script,
>> > which comes afterwards in the instructions?
>>
>> Different build folders are not an explicit requirement for different
>> MACHINES (or in some cases unless there are some conflicts that are
>> unknown diferrent distros - don't go out of your way to do this
>> though). In fact if two MACHINES are the same ARCH you can reuse
>> components between and save a lot of build time. That or use
>> sstate-cache between two build folders which won't be quite as fast
>> but almost...
>>
>> > Also, those instructions imply that I should run that script in the
>> > yocto/poky directory, since that's where the script is
>> located, but the
>> > meta-intel is "upstairs" from that, which seems odd.
>>
>> Should not matter, you add meta-intel to 'conf/bblayers/conf' later.
>> Unless this is possibly done for you via script - but I don't think
>> any scripts in poky do this for you. Either way you can checkup on
>> things layer to make sure the require layers are included.
>>
>> > I'm confused by all this, but more to the point, I'm afraid
>> of doing the
>> > wrong thing, and clobbering the Gumstix stuff, which took a
>> day and a half
>> > to build. I expect the Atom build will also take a long
>> time, but I don't
>> > want to have to do it two more times.
>>
>> You are mixing gumstix and poky distros in one build folder? That
>> could work as mentioned above, but it might encounter issues. I don't
>> think it's regularly tested though so YMMV. My suggest would be to
>> share the sstate-cache between the two build environments. So if one
>> package has already been built it's reused (and the signatures match -
>> which just means it's deemed compatible between machines)
>>
>> It's also quite likely you won't save much build time since gumstix
>> and poky will be using different ARCHs and all the recipes will be
>> rebuilt anyways. Again not really that familiar with gumstix so some
>> statements above could be a bit off.
>
> That's what I thought. You can't really share much of anything between a
> Gumstix and an Atom, so I'm using a separate build tree.
>
> But it's not working. The instructions tell me to set MACHINE to
> "cedartrail" or "cedartrail-nopvr" in local.conf, so I chose the latter
> since I'm doing a GUI-less system. And then it tells me to run "bitbake
> core-image-sato" which seems strange, since "sato" refers to a desktop
> manager or something graphical. After a lot of DEBUG output, I get the
> following error message:
>
>     ERROR:  OE-core's config sanity checker detected a potential
>         misconfiguration.
>         Either fix the cause of this error or at your own risk disable the
>         checker (see sanity.conf).
>         Following is the list of potential problems / advisories:
>         Please set a valid MACHINE in your local.conf or environment
>
> Also, I notice among the debug output, early on:
>
>     DEBUG: CONF file 'conf/machine/cedartrail-nopvr.conf' not found
>
> even though that file exists in poky/meta-intel.

Is the layer that contains this file in conf/bblayers.conf?

> Is the problem that I'm making the wrong image for a GUI-less system? Where
> are targets like "core-image-sato" defined? I don't see any file of that
> name, with a .bb or any other extension, other than a prebuilt image.
>
> I get the feeling I'm missing something.

What about just building core-image-minimal (this image has no gui)?

> By the way, I'm using the poky tree that was downloaded as a result of my
> Gumstix build, except for the meta-intel subdirectory. Is that wrong?

It could be.... you should check the differences between the two trees
each one is expecting (e.g. they could be based on different releases)

-M