Beta testing • Re: AB Firmware

From what I gather, it seems it is still possible to use recovery.bin with pieeprom.upd as before.

Yes. All the existing methods to flash the firmware image onto the EEPROM still work in the same way they did before by overwriting the entire EEPROM.

from what I can tell I can even use it to flash a new version without rebooting.

In the same way that you could use flashrom to flash a new firmware image to EEPROM without rebooting. The firmware that's actively running doesn't change, it's whatever was loaded from EEPROM at boot time.

I'm not entirely sure how tryboot in rpi-eeprom-ab is related to the bootloader tryboot

They are completely separate. The only way to interface with the AB firmware tryboot flag is using rpi-eeprom-ab tryboot.

So I can 'rpi-eeprom-ab update partition.bin' into the spare EEPROM partition, 'reboot "tryboot x"'. Then probe the tryboot flag and then 'rpi-eeprom-ab commit'?

The correct way to use rpi-eeprom-ab directly with tryboot isIf the hash you give to mark-partition-valid doesn't match whatever is currently in the next EEPROM partition then the partition won't be marked as valid and tryboot will have no effect, you will continue to boot from your existing committed partition.

Before you commit you can check if you did successfully boot from your new update with:which should return 0 if it booted from the uncommitted partition. If it returns 1 then either the new partition hadn't been marked valid, tryboot wasn't set or the first binary blob required (bootsys) in the partition couldn't be found so it reverted to the committed partition (e.g. you decided to have partition.bin as entirely zeros). Note: if it does find the first binary blob in the partition you are trybooting from then it will stick to that partition for the rest of the boot process, so it won't do any kind of attempt to revert to the committed partition if there are any other problems later in the boot process with this partition.

Also I guess I'll have to use the bootloader watchdog to make this work fully automated in case the tryboot'ed firmware doesn't start for any reason?

Yes use a bootloader watchdog (https://www.raspberrypi.com/documentati ... OG_TIMEOUT) to automate recovering from a tryboot'ed firmware that fails to boot. The tryboot flag is cleared immediately after being read during boot so when the system restarts it will use the committed partition.

Statistics: Posted by mathewb64 — Wed Feb 18, 2026 11:16 am

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