[Xiaomi Poco F3 / Xiaomi Mi 11X / Redmi K40] DarthJabba9:
Initial installation of Vendor_Boot ROMs for Alioth

1. You will normally need a PC / Laptop, because you are likely to need to flash some things in bootloader mode (at least, when installing a vendor_boot ROM for the first time)

2. It is best to follow the instructions given by the ROM's developers

3. However, you should be able to do an initial installation of a vendor_boot ROM in the usual way,

using the standard OrangeFox Recovery

for Alioth. If you want to do so, please

note the following

:

(a) You

must

untick "Reflash OrangeFox after flashing a ROM"

before

flashing a vendor_boot ROM with a standard recovery

(b) The vendor_boot ROM (as is normal with A/B devices) will replace the installed recovery with its own vendor_boot recovery

(c) So, you must flash the OrangeFox vendor_boot recovery zip immediately after flashing the vendor_boot ROM

(d) You should then reboot to recovery immediately after this, and then

format

the data partition, using the newly installed vendor_boot OrangeFox

before

booting to system

(e) After this, you should be able to boot to the OrangeFox vendor_boot recovery in the normal way

(f) Formatting the data partition will have removed the custom OrangeFox files in the internal storage. You can restore them later by flashing the OrangeFox zip again.

Subsequent installations of new Vendor_Boot ROMs for Alioth

- Format the data partition

- Flash the new vendor_boot ROM with the installed OrangeFox vendor_boot recovery (this will also replace OrangeFox with the ROM's own recovery)

- Flash the OrangeFox vendor_boot recovery zip file again

- Format the data partition again (you may first have to reboot OrangeFox, if there is a problem with formatting)

- Reboot to system

NOTE

: some vendor_boot ROMs (eg, Paranoid aospa topaz) require the data partition to be formatted with their own ROM recovery. With such ROMs, do not follow the instructions above about formatting with OrangeFox. Instead, you will need to follow a slightly different process:

(a) Flash the ROM

(b) Reboot immediately to recovery (this will load the ROM's own recovery)

(c) Format the data partition

(d) Flash the OrangeFox vendor_boot recovery

(e) Reboot to system

Issues with Vendor_Boot ROMs

Every vendor_boot ROM for alioth that I have tested (ie, all in the list provided in the OP) had (at the time of testing) an incomplete implementation of the fastbootd mode.

This means that you cannot flash a vendor_boot ramdisk to the vendor_boot partition, as envisaged by Google (see this Google documentation on fastbootd and especially this section).

Thus the only way to replace/update the vendor_boot recovery is to flash a full vendor_boot recovery image to the vendor_boot partition (ie, replace the entire partition, rather than just the ramdisk). This is potentially problematic. So far, it has worked fine for all the ROMs listed above. But this is not guaranteed to continue forever.

Solution?

The real solution is for the ROM devs to have a full implementation of fastbootd. It might just be a simple case of using a v4 header (ie, BOARD_BOOT_HEADER_VERSION := 4). Or it might involve something a little bit more. In any case, it is an easy and uncomplicated task.

DIRE WARNING!!!

Do

NOT

flash a standard recovery onto a "vendor_boot" ROM. If you do, you

will

trash the boot partition, with

all

of the following consequences:

a. The ROM will not boot, and

b. The recovery will not boot, and

c. You will not be able to "fastboot boot" a recovery image of any kind.

In short,

you will get a bricked device

that can only boot successfully into the bootloader mode. And then you will have a very interesting experience in trying to restore the device from bootloader mode. You really do

not

want to go down this route!

* If you get this kind of problem, you might want to check this thread: https://xdaforums.com/t/temporary-recovery-a13-a14-more.4639865/

Is there any advantage at all in using vendor_boot-as-recovery?

1. Generally, separating the recovery from the boot partition can be a good thing.

2. If you are into rooting your device, there is an advantage to having a different partition for the recovery (ie, other than the boot partition). Because a vendor_boot recovery must be flashed to the vendor_boot partition, updating your vendor_boot recovery (or replacing it with another vendor_boot recovery) would not touch your boot partition, meaning that it should have no impact on your magisk installation.

3. However, going down the vendor_boot route is dubious, because there was already that solution long ago (with A-only devices, which had dedicated recovery partitions). Google could simply have returned to having dedicated recovery partitions again with A/B devices (at least one OEM has A/B devices with real/separate recovery partitions). Why Google chose the vendor_boot route is anyone's guess. This route is especially problematic because you can't "fastboot boot" a vendor_boot recovery image, meaning that there is no way to test it without first flashing it. That is a

major

problem, given the high risk of bricking a device during testing of recovery builds before release.

If/when I come up with any other advantage of vendor_boot, I will update this section ...