[Buildroot] [PATCH 1/2] board/kontron/pitx-imx8m: use extlinux instead of U-Boot boot script

[Thomas Petazzoni]

On Mon, 17 Jan 2022 09:06:16 +0100
Heiko Thiery <heiko.thiery at gmail.com> wrote:

> Signed-off-by: Heiko Thiery <heiko.thiery at gmail.com>
> ---
>  board/kontron/pitx-imx8m/boot.cmd      | 8 --------
>  board/kontron/pitx-imx8m/extlinux.conf | 4 ++++
>  board/kontron/pitx-imx8m/genimage.cfg  | 5 +++--
>  board/kontron/pitx-imx8m/post-build.sh | 7 +++++--
>  board/kontron/pitx-imx8m/post-image.sh | 2 +-
>  configs/kontron_pitx_imx8m_defconfig   | 3 +--
>  6 files changed, 14 insertions(+), 15 deletions(-)
>  delete mode 100644 board/kontron/pitx-imx8m/boot.cmd
>  create mode 100644 board/kontron/pitx-imx8m/extlinux.conf

I have applied, but I am a bit worried about things are going on with
this switch to extlinux.conf.

Indeed, we have:

 * Platforms where the UUID is hardcoded into genimage.cfg and
   extlinux.conf, such as board/beaglev/

 * We have platforms where a "uuid" variable in filled in U-Boot before
   triggering the extlinux.conf logic, and therefore extlinux.conf uses
   root=PARTUUID=${uuid}. For example
   board/freescale/imx7dsdb/rootfs_overlay/boot/extlinux/extlinux.conf,
   board/orangepi/orangepi-zero/boot.cmd,
   board/solidrun/mx6cubox/rootfs_overlay/boot/extlinux/extlinux.conf,
   board/technexion/imx6ulpico/rootfs_overlay/boot/extlinux/extlinux.conf,
   and a few others.

 * We now have platforms (kontron/smarc-sal28 and kontron/pitx-imx8m)
   where a random UUID is generated in the post-build script, and used
   in genimage and extlinux.conf.

I'm not sure where we want to go, and how much we want to enforce "best
practices" that are common on all platforms, or just let each platform
do its little business.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com