[Timon3]

Does this have a mechanism for automatic redundant OS upgrades? I just built a Yocto-based distribution for a board based on rk3399, but the currently integrated U-Boot is not in the best state. This could be a great alternative if it really is a bit easier to integrate/build upon.

[daneel_w]

It's just a bootloader, with a few tricks up its sleeve. All it does is letting you boot from any storage medium you want (most notably NVMe) instead of being restricted to the hardcoded sequence of the boot ROM.

[Timon3]

I understand that part. What I'm talking about specifically is part of a bootloader, see for example this page in the documentation of SWUpdate: https://sbabic.github.io/swupdate/bootloader_interface.html

By adding communication between the OS and the bootloader it's possible to implement redundant updates for whole partitions (specifically A/B-updates with a boot counter). U-Boot supports this (depending on the state of the vendor-provided fork better or worse), and Tow-Boot seems to be based on U-Boot.

[megous]

One problem with opinionated builds of U-Boot is that you'll have more work figuring out what's enabled in its config. Configure and build your own if you want this kind of control.

[irusensei]

The tow-boot software devs goes out of the way to say they are offering a boring PC boot loader experience so I wouldn’t expect any advanced features other than booting from devices.

[yencabulator]

PC boot loaders have been able to fall back to previous configurations on boot failure ("automatic redundant OS upgrades") for a long time[1], so that's not a valid excuse.

https://systemd.io/AUTOMATIC_BOOT_ASSESSMENT/

https://www.gnu.org/software/grub/manual/grub/html_node/fall...

https://www.gnu.org/software/grub/manual/legacy/Booting-fall...

[1]: Minimum about 23 years, from personal use in creating a product with A/B-root partitions.

[daneel_w]

I don't know if it retained swupdate functionality, or if it's drop-in compatible with u-boot's such.

[rjsw]

It is a bootloader bundled with the ARM64 firmware. That means you don't need to add the firmware to each OS that you might want to use so it is easier to switch between them.