[Nexus 6P General] osm0sis:
Update Flashing Instructions

Keep N5X-6P_BLOD_Workaround_Injector_Addon-AK3-signed.zip on your device sdcard, henceforth referred to as BLOD AK3 zip

The correct manual order for a clean flash is: ROM -> root -> custom kernel -> BLOD AK3

Always flash the BLOD AK3 zip last!

Reflashing the BLOD AK3 zip will likely be required after anything that could modify the boot.img or recovery.img, including (but not limited to): ROM updates, custom kernel updates, custom recovery updates.

ROMs:

On custom ROMs with built-in Flash After Update (i.e. OmniROM-based), place your root (if using SuperSU), custom kernel and BLOD AK3 zip in /sdcard/OpenDelta/FlashAfterUpdate/ ensuring the BLOD AK3 is last in the directory listing so that they will be flashed after each update.

On custom ROMs that do not have built-in Flash After Update (i.e. LineageOS-based), you may add my FlashAfterUpdate addon.d script to /system/addon.d/ and then place your root (if using SuperSU), custom kernel and BLOD AK3 zip in /sdcard/FlashAfterUpdate/ ensuring the BLOD AK3 is last for the same effect: flashed after every OTA. (y):)

On stock ROM rooted with SuperSU (SuperSU v2.82-SR5 recommended) instead of tapping "Reboot & Install" once the OTA is downloaded you should use @Chainfire's excellent FlashFire app to queue the OTA from /data/ota_package/update_s.zip then queue the SuperSU zip, custom kernel and BLOD AK3 zip, ensuring the BLOD AK3 is last. This is how I have mine set up, since this is by far the most seamless. Be sure to disable EverRoot since SuperSU v2.82-SR5 is newer than the SuperSU included in FlashFire.

On stock ROM rooted with Magisk you must uninstall Magisk from within Magisk Manager to restore your stock boot.img, reboot the ROM to restore your stock recovery partition, tap "Reboot & Install" once the OTA is downloaded, then go through the steps above to flash the 4core TWRP and BLOD AK3 zip again. I definitely recommend SuperSU on this device to avoid the hassle of unrooting and/or messing with factory images.

Kernels:

Custom kernels can be flashed from an app like Franco Kernel Manager & Updater, which can be set to flash without reboot for Franco Kernel updates, or "Flash only" can be chosen in the manual flasher. The FK app supports all types of AnyKernel3 zip so the BLOD AK3 zip may then be flashed after the custom kernel zip to repatch the new kernel's ramdisk.

For other kernel managers that don't support AK3 zips, simply reboot to recovery and flash the BLOD AK3 zip from there to repatch before attempting to boot the ROM again. Also see above under "stock ROM rooted with SuperSU", since FlashFire also works perfectly for this use-case, queuing the custom kernel zip and then the BLOD AK3 zip, with FlashFire's EverRoot option disabled since the device is already rooted.

Recoveries:

Download the updated custom recovery .img and, without flashing it, reboot to recovery, use TWRP's flash image feature to flash the new recovery.img, then without rebooting immediately flash the BLOD AK3 zip to patch it. You can then dump/backup the recovery partition if you want it as a recovery.img. Custom recovery updates can also be done from FlashFire, queuing the BLOD AK3 zip afterward, but the "Preserve recovery" feature must be disabled.

If you prefer to stay on stock recovery for some reason, you can still use TWRP to do the above without flashing TWRP to the device by using "fastboot boot twrp-3.2.1-0-fbe-4core-angler.img".

My development work on my many projects comes out of my free time, so if you enjoy this project or anything else I've done on xda, please consider sponsoring my ongoing work using my GitHub Sponsors profile. For a one-time donation you can hit the donate link from my profile. Thank you for your support!

Changelog

2018-01-15 - Original post in other BLOD threads.

2018-07-21 - Update AK2 Core+Backend files to latest, add searching of all init.*.rc files for problematic cpuset commands which were popularized by Franco Kernel and are now used by multiple custom kernels. (6758 downloads)

2019-10-30 - Update to AnyKernel3, add support for SAR and 2SI Treblized ROMs. (1720 downloads)

2020-01-16 - Update AK3 Core+Backend files to latest to fix AVBv1 signing in recovery on Android 10, update boot_signer-dexed.jar. (570 downloads)

2020-02-17 - Update AK3 Core+Backend files to latest to fix SAR mount support in fragmented TWRP and Lineage 16+17 Recovery. (1412 downloads)

2020-05-25 - Update AK3 Core+Backend files to latest to improve SAR mount support in Lineage 17 Recovery and AVBv1 signing. (1789 downloads)

2021-07-21 - Update AK3 Core+Backend files to latest to support Lineage 18.1 recovery and Android 11 ROMs.

Good luck and enjoy!