Remove the legacy extension board implementation now that all boards
have been converted to use the new UCLASS-based framework. This
eliminates lines of legacy code while preserving functionality
through the modern driver model approach.

Update the bootstd tests, due to the removal of extension hunter.

Signed-off-by: Kory Maincent (TI.com) <kory.maincent@bootlin.com>

Introduce UCLASS-based extension board support to enable more
standardized and automatic loading of extension board device tree
overlays in preparation for integration with bootstd and pxe_utils.

Several #if CONFIG_IS_ENABLED are used in cmd/extension_board.c to ease the
development but don't worry they are removed later in the series.

Signed-off-by: Kory Maincent (TI.com) <kory.maincent@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Relocate extension board support from cmd/ to boot/ directory in
preparation for converting the extension framework to use UCLASS.
Also improve code style by applying reverse xmas tree ordering.

Signed-off-by: Kory Maincent (TI.com) <kory.maincent@bootlin.com>

Martin Schwan <m.schwan@phytec.de> says:

This series implements a new bootmeth for RAUC A/B systems. RAUC (Robust
Auto Update Controller) is a lightweight update client, providing "Safe
and Secure OTA Updates for Embedded Linux". See the following links for
more information about RAUC:

  https://rauc.io/
  https://rauc.readthedocs.io/en/latest/

PHYTEC uses RAUC in its Yocto based distribution "Ampliphy" as the
default way of updating embedded devices based on PHYTEC hardware. So
far, the logic selecting the correct partitions and files to boot was
being implemented in the U-Boot environment. While this is a
straightforward way to do it, adding and supporting new platforms became
somewhat tedious and is platform-specific. The introduction of U-Boot's
"Standard Boot" provided a convincing alternative, promising a simpler
and more portable way of booting, even for RAUC systems. This led me to
implement a new bootmeth supporting RAUC A/B systems. Note, that this
new bootmeth is not proprietary to PHYTEC products and is designed to
work on other hardware with a RAUC A/B system, too.

The bootmeth currently only supports symmetric A/B partitioning layouts.
E.g. A/rescue is not (yet) supported. The partition indexes and default
slot tries can be specified via configuration options.

For now, the bootmeth_rauc uses a similar approach for loading the
Kernel and device tree as the bootmeth_script, in that it requires a FIT
containing a U-Boot script loading the desired distro. It could be
possible to support booting without a script and load the Kernel and DT
directly with this bootmeth, but I found the script method to be very
flexible for now, in letting the distro decide what to load.

The bootmeth_rauc was tested on a phyBOARD-Pollux i.MX8M Plus [1] with
BSP-Yocto-Ampliphy-i.MX8MP-PD24.1.2 [2].

Supported boot devices are currently only MMC devices, but it should be
possible to add SPI flashes in the future.

To test this patch stack with PHYTEC's phyBOARD-Pollux i.MX8M Plus
board, you need to adjust the boot files to include the boot.scr.uimg
containing the distro's boot script and set "optargs" to "${raucargs}"
in it. Also disable any legacyboot in the U-Boot environment and simply
boot with Standard Boot:

  bootmeth order rauc
  bootflow scan -lb

[1]: https://www.phytec.eu/en/produkte/single-board-computer/phyboard-pollux/
[2]: https://download.phytec.de/Software/Linux/BSP-Yocto-i.MX8MP/BSP-Yocto-Ampliphy-i.MX8MP-PD24.1.2/

Link: https://lore.kernel.org/r/20250604-wip-bootmeth-rauc-v3-0-f9fad913c57e@phytec.de
[trini: Don't enable by default]

Add a bootmeth driver which supports booting A/B system with RAUC as
their update client.

Signed-off-by: Martin Schwan <m.schwan@phytec.de>
Tested-by: Wadim Egorov <w.egorov@phytec.de>

It is useful to be able to edit text, e.g. to allow the user to edit the
environment or the command-line arguments for the OS.

Add the beginnings of an implementation. Future work is needed to finish
this: keypress handling and scrolling. For now it just displays the
text.

Signed-off-by: Simon Glass <sjg@chromium.org>

Tom Rini <trini@konsulko.com> says:

This series switches to always using $(PHASE_) in Makefiles when
building rather than $(PHASE_) or $(XPL_). It also starts on documenting
this part of the build, but as a follow-up we need to rename
doc/develop/spl.rst and expand on explaining things a bit.

Link: https://lore.kernel.org/r/20250401225851.1125678-1-trini@konsulko.com

It is confusing to have both "$(PHASE_)" and "$(XPL_)" be used in our
Makefiles as part of the macros to determine when to do something in our
Makefiles based on what phase of the build we are in. For consistency,
bring this down to a single macro and use "$(PHASE_)" only.

Signed-off-by: Tom Rini <trini@konsulko.com>

Rather than building a command line for each operation, use the
functions provided by the bootm API.

Make sure that the bootm functions are available if pxe_utils is used.

Since SYS_BOOTM_LEN is not present for the tools-only build, adjust the
code to handle that.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>

So far only VBE-simple is implemented in U-Boot. This supports a single
image which can be updated in situ.

It is often necessary to support two images (A and B) so that the board
is not bricked if the update is interrupted or is bad.

In some cases, a non-updatable recovery image is desirable, so that the
board can be returned to a known-good state in the event of a serious
failure.

Introduce ABrec which provides these features. It supports three
independent images and the logic to select the desired one on boot.

While we are here, fix a debug message to indicate the function it
called. Provide a maintainers entry for VBE.

Note that fwupdated only supports VBE-simple so far, but supports for
ABrec will appear in time.

Signed-off-by: Simon Glass <sjg@chromium.org>