[PATCH v3 0/2] bootstd: New bootmeth for RAUC A/B systems
Tom Rini
trini at konsulko.com
Fri Jun 6 15:50:56 CEST 2025
On Fri, Jun 06, 2025 at 06:59:05AM +0000, Martin Schwan wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA512
>
> Hi Simon,
>
> On Thu, 2025-06-05 at 11:29 -0600, Simon Glass wrote:
> > Hi Martin,
> >
> > On Wed, 4 Jun 2025 at 06:16, Martin Schwan <m.schwan at phytec.de>
> > wrote:
> > >
> > > 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
> > >
> > > Regards,
> > > Martin
> > >
> > > [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/
> > >
> > > ---
> > > Changes in v3:
> > > - Invert if-statement check for setting default value of
> > > BOOT_*_LEFT env
> > > variables. This would falsely trigger an error message before.
> > > - Link to v2:
> > > https://lore.kernel.org/r/20250602-wip-bootmeth-rauc-v2-0-9d2384131486@phytec.de
> > >
> > > Changes in v2:
> > > - Remove LOG_DEBUG from boot/bootmeth_rauc.c
> > > - Reorder asm/cache.h include to be last
> > > - Do not check for RAUC-specific files in the rootfs anymore. This
> > > does
> > > not work on encrypted root filesystems and is not a stable
> > > indicator
> > > for a functioning RAUC system.
> > > - Add a description of the term "slot" in the corresponding private
> > > struct.
> > > - Remove boot tries left from struct distro_rauc_slot. The boot
> > > tries
> > > are read directly from the environment, as that's the only
> > > correct
> > > source RAUC is relying on.
> > > - Remove the current boot_order from struct distro_rauc_priv, for
> > > the
> > > same reason as above (env is correct source).
> > > - Add function for retrieving a slot struct, to ease finding the
> > > right
> > > one when e.g. iterating or getting by name.
> > > - Fix multiline comments.
> > > - Fix various if-statements which were explicitly comparing to 0 or
> > > NULL.
> > > - Free various, temporary instances of allocated string lists.
> > > - Set default env values for BOOT_ORDER and associated BOOT_*_LEFT
> > > variables. These variables are mandatory for RAUC to work.
> > > - Use calloc() instead of malloc() for allocating the private
> > > slots.
> > > - Use config options for configuring the partitions and default
> > > boot
> > > order, instead of setting them via the U-Boot env.
> > > - Use bootstd_get_prefixes()'s return value and check all available
> > > prefixes for the boot script.
> > > - Add a proper boot order selection logic for the rauc bootmeth,
> > > similar
> > > to the previous environment scripting, with fallbacks and slot
> > > try
> > > checks.
> > > - Introduce config option for resetting all slot tries in case they
> > > are
> > > all zero. This may prevent a system from locking up in the
> > > bootloader.
> > > - Rename env variable "mmcroot" to "distro_rootpart", to be in line
> > > with
> > > "distro_bootpart".
> > > - Change the bootmeth flag to "global", as the rauc bootmeth does
> > > not
> > > work for individual partitions.
> > > - Update documentation accordingly.
> > > - Link to v1:
> > > https://lore.kernel.org/r/20250129-wip-bootmeth-rauc-v1-0-6308e732f314@phytec.de
> > >
> > > ---
> > > Martin Schwan (2):
> > > bootstd: Add implementation for bootmeth rauc
> > > doc: Add description for bootmeth rauc
> > >
> > > boot/Kconfig | 51 +++++
> > > boot/Makefile | 1 +
> > > boot/bootmeth_rauc.c | 432
> > > +++++++++++++++++++++++++++++++++++++++
> > > doc/develop/bootstd/index.rst | 1 +
> > > doc/develop/bootstd/overview.rst | 1 +
> > > doc/develop/bootstd/rauc.rst | 56 +++++
> > > 6 files changed, 542 insertions(+)
> > > ---
> > > base-commit: b22a276f039f818d5564bec6637071cfc8a7e432
> > > change-id: 20250129-wip-bootmeth-rauc-03b5e2dd88f4
> > >
> > > Best regards,
> > > --
> > > Martin Schwan <m.schwan at phytec.de>
> > >
> >
> > Great to see this. Could you please add a test, e.g. to
> > test/boot/bootflow.c ? Let me know if you need help.
>
> Thank you! :)
>
> I will have a look into adding a test for it. Sorry, that I didn't make
> it for the first iteration, as you mentioned it previously. Will it be
> okay, if I add this in a separate patch?
>
> I'll probably not have time for this until end of June, as I'm on
> vacation the next two weeks. But I definitely have it on my agenda.
We can add the tests in a follow-up, that's fine. I'm assuming you'll be
putting this in to some test framework for practical testing internally?
--
Tom
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 659 bytes
Desc: not available
URL: <https://lists.denx.de/pipermail/u-boot/attachments/20250606/1fdee272/attachment.sig>
More information about the U-Boot
mailing list