Fail Safe bootloader

[shubhamm098]

I have three partitions ota0 ota1 and ota2. ota0 contains the firmware upgrade via tusb and also checks for some pins voltage and a nvs flag to decide if it have to do the usb mass storage upgrade or not otherwise boot the ota1 or ota2 partiton based on nvs flag.

If yes it will show a drive on laptop and firmware upgrade can be done. I want ota0 should always boot and check for the conditions . But the problem is once boot partition is set to ota1 or ota2 bootloader will not boot ota0 until and unless application not set boot partition back to ota0.

If somehow application not able to do it device will be bricked. Any solution how can I achieve it?