[Nothing Phone 1] markus_1995:
Hello guys.

I need some help and advice with a broken slot and verity mode issue. A/B partitions and AVB are somewhat new to me, so please excuse my ignorance.

I have previously unlocked and rooted my phone without problems, and have been using it for a month. Two days ago, I wanted to start over and flashed the 1.1.7 Global ROM from https://reindex-ot.github.io/ as I have used this package twice before with no errors.

First, I did a wipe but forgot to unroot Slot B (my big mistake) and since it was on the current 1.1.7 OS, I switched slots and flashed the files to Slot A and rebooted directly (fastboot boot) with a patched boot image. After this point, I am no longer sure which slot I was on, as I assumed I would be on Slot A. I don't know if Slot A was already damaged, and I was actually booted into Slot B.

After a successful boot, I installed Magisk, but the restart dialog came up and I accidentally clicked without patching the original boot image. I did another direct boot with a patched boot image, and then patched the supposedly untouched boot image directly and installed it, then rebooted to the OS successfully.

Next, I went to fastboot to check "getvar all" but here's where two errors came up. FIrst, I realized my verity mode was now set to "false", whereas it was always "true" during two other root attempts in the past month. Second, I realized I was in Slot B instead of the one I previously switched to.

I tried to switch back to Slot A, but it boots for a few seconds, fails, then falls back to Slot B. I then tried twice to flash all the usual partitions back to both slots and try them again, and Slot A consistently fails. It is my belief I may have patched a previously rooted boot image in Slot B, and somehow, verity was messed up during that step. At one point, Slot B also failed and I was dumped back to the bootloader. Now, I have one failed slot and verity mode off, so I need some help or advice.

Is there anyway I can re-enable verity, and are there any special partitions I need to flash to get Slot A working?

I previously made a backup of all smaller partitions (eg "modem" "persist" etc) except the "super" and "userdata" partitions with Wanam's partition backup tool. I believe this backup was made directly after I unlocked while on Slot A with 1.1.7 ROM after an OTA update, whereas Slot B at that time would be on 1.1.6 ROM. I think this is true because the sizes of some compressed images (the "abl" "align to 128k" and "boot") differs slightly for each slot's backup.

Will manually flashing the backups to both slots fix anything? Can I revert back to that point in time just after unlock? I am hesitant to do so because I no longer trust my backups in case flashing them qualifies as a "downgrade" (in the case of Slot B using 1.1.6 ROM). Or will manually flashing the backups for Slot A (the 1.1.7 ROM backup) to both slots ensure they are both considered "identical" to the current bootloader and not cause it to trip?

If this is not possible, will flashing a third party ROM to both slots before flashing NothingOS again help, especially if one slot has gone bad? I realize some third party ROMS first require both slots to have the current 1.1.7 ROM before flashing any third party software. I saw someone mention using RiceDroid to "downgrade" from his NothingOS 1.5 beta back to 1.1.7, but I am unsure if this works. I don't particularly mind not using NothingOS and can live with a third party ROM permanently, but I need to fix the damaged slot and maybe get verity back. I assume verity is useless in a systemless root setup with an unlocked bootloader (true or false?) but I wish to get everything back like it was before.

I apologize if my post is too lengthy, I have never posted to forums before, but I wish to be as accurate in describing my issue. Please advise if you can and thank you for any assistance.