TBYB stands for Try-Before-You-Buy that is a well known feature of the RP2350 (datasheet page. 363) that allows to do a completely safe cycle of version upgrade.
After the RP2350 gets updated as FLASH_UPDATE (via OTA or using picotool and writing in one of the AB partitions) if this TBYB flag is enabled in the image, a watchdog starts and has a timer for the executed application to do a call to remove it and prove the updated image works good. This serves as a way to get back to a working partition if the updated one is corrupt.
What I am asking is if FreeRTOS presence may interfer in how this watchdog or the image is booted since the same secured pico device can run another baremetal project that has an OTA feature with TBYB and fails to boot images of the same project upgraded with FreeRTOS. I find no difference on how I set the rollback version, the TBYB flag and sign the binary between the two projects so I'm considering it's due FreeRTOS but wanted to ask here just in case someone faced this issue or has experience with FreeRTOS in ARM Secure functionalities.
I hope that's clear now. Sorry, I assumed TBYB was a known function of the RP2350.
thx for ur time!!
After the RP2350 gets updated as FLASH_UPDATE (via OTA or using picotool and writing in one of the AB partitions) if this TBYB flag is enabled in the image, a watchdog starts and has a timer for the executed application to do a call to remove it and prove the updated image works good. This serves as a way to get back to a working partition if the updated one is corrupt.
What I am asking is if FreeRTOS presence may interfer in how this watchdog or the image is booted since the same secured pico device can run another baremetal project that has an OTA feature with TBYB and fails to boot images of the same project upgraded with FreeRTOS. I find no difference on how I set the rollback version, the TBYB flag and sign the binary between the two projects so I'm considering it's due FreeRTOS but wanted to ask here just in case someone faced this issue or has experience with FreeRTOS in ARM Secure functionalities.
I hope that's clear now. Sorry, I assumed TBYB was a known function of the RP2350.
thx for ur time!!
Statistics: Posted by vicenspb9 — Sat Dec 13, 2025 12:10 pm