[yocto] [OE-core] [PATCH 1/2] barebox: add initial support

[Enrico Jörns]

Hi Richard,

Am Freitag, dem 03.02.2023 um 14:17 +0000 schrieb Richard Purdie:
> On Fri, 2023-02-03 at 14:50 +0100, Marco Felsch wrote:
> > This adds the support for the barebox bootloader to oe-core. The recipe
> > is based on the recipe found in meta-ptx [1] with a few minor adaptions.
> > 
> > This basic support includes the bootloader and the target tools to
> > interact with the bootloader. The host tools support is not part of
> > this commit. This will be added later on as separate recipe.
> > 
> > [1] https://github.com/pengutronix/meta-ptx/tree/master/recipes-bsp/barebox
> > 
> > Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
> > ---
> >  meta/conf/documentation.conf                  |   7 +
> >  meta/recipes-bsp/barebox/barebox.inc          | 123 ++++++++++++++++++
> >  meta/recipes-bsp/barebox/barebox_2023.01.0.bb |   5 +
> >  ...IMAGE_COMPRESSION-per-default-to-lz4.patch |  40 ++++++
> >  4 files changed, 175 insertions(+)
> >  create mode 100644 meta/recipes-bsp/barebox/barebox.inc
> >  create mode 100644 meta/recipes-bsp/barebox/barebox_2023.01.0.bb
> >  create mode 100644 meta/recipes-bsp/barebox/files/0001-pbl-set-IMAGE_COMPRESSION-per-default-
> > to-lz4.patch
> 
> In order to add something to OE-Core, we need to see it being used by a
> reasonable portion of the ecosystem. Is there enough usage of barebox
> on common boards that justifies this?

I understand that not each and every package can and should be added to OE-core, so let me provide
my view on why adding barebox could be reasonable.

First of all, since it is a bootloader and oe-core's purpose is to provide basic common recipes
required to bring up a device, I found it to be a proper location for the recipe.
It does not add any further dependencies in the oe-core ecosystem so additional maintenance should
be limited in scope.

With over 300 individual contributors and regular monthly releases [1] I would call the barebox
bootloader a common, stable and mature project that is around since ~2009 and provides support for a
wide range of architectures, SoCs and platforms [2] including freely available common boards like
RPI, beaglebone, i.MX eval kits and UEFI in general.

Ever since, barebox has also been used by different hardware vendors (e.g. [4]) and was chosen by
Kalray [5] as their bootloader. Of course, as you know, it is always difficult to have a reliable
overview of the user base of an open source project as barebox.

So far there are already a number of barebox oe recipes around [3] that I find worth to consolidate
with adding one reference recipe to oe-core.


The question if these are sufficient arguments for adding barebox to oe-core probably needs to be
answered by the broader community, but I found it to be a good added value to have a bootloader in
oe-core that adapts many of the well-known schemes of Linux and focuses on being developer-friendly
and framework-driven.
(Let me just drop [6] for those interested in a bit details on what I summed up very roughly here.)

> I noticed there is no maintainers entry being added so this will throw
> QA errors on the autobuilder.

I would take responsibility for the recipe, backed by other barebox developers here.

> Also, I'm not sure adding doc varflags for individual recipe variables
> to documentation.conf makes sense. We should probably have them in the
> recipe or just put entries into the manual?

To be honest, this was inspired by the UBOOT_ variables that are placed in documentation.conf thus
we assumed this could be a proper place. We can simply move them into the recipe to limit intrusion
into the rest of the oe ecosystem.


Many thanks for your initial thoughts! Best regards,

Enrico

> Cheers,
> 
> Richard


[1] https://barebox.org/download/
[2] https://barebox.org/doc/latest/boards.html
[3] http://layers.openembedded.org/layerindex/branch/master/recipes/?q=barebox
[4] https://www.phytec.eu/en/cdocuments/?doc=YQ4RCg
[5] https://en.wikipedia.org/wiki/Kalray
[6] https://www.youtube.com/watch?v=fru1n54s2W4&ab_channel=TheLinuxFoundation

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