Hi Martin, On Wed, 4 Jun 2025 at 06:16, Martin Schwan <[email protected]> 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/[email protected] > > 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/[email protected] > > --- > 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 <[email protected]> >
Great to see this. Could you please add a test, e.g. to test/boot/bootflow.c ? Let me know if you need help. Regards, Simon
