Originally Posted by raashnal
Please excuse me if these are stupid procedure clarification requests but I came to the Oneplus 6 from the HTC U11 where we flashed Roms and kernels using TWRP without giving it a second thought, so the procedure to flash roms on the Oneplus 6 is much more complicated.
1) If I am on a stock rom I just flash the Custom Magisk Installer (optionally reboot back into TWRP) and then install the Magisk Module and then reboot back into the system and all the updates should have been made.
2) If I am already on Renovate ICE rom then I can just flash the new Magisk module using TWRP. Reboot back into the system and all the changes will have been made.
3) If I am on a custom rom (other than Renovate ICE) then I need to extract the system.img from the stock rom (same version as which the ROM is based on) and then Fastboot flash the stock system.img to the correct slot. How do I know which is the correct slot? How do I make sure that it flashes to the correct slot? Is there something I need to the “Fastboot flash system system.img” command to make sure it flashes to the correct slot?
I screwed up rooting and installing TWRP last night and got stuck in a Fastboot boot loop and it took me 6 hours to correct it. So please excuse my paranoia.
just try to use correct terms without showing annoyance and frustration about certain facts.
this is related to A/B infrastructure and "Treble" which is the future and applies to several if not many devices already.
treble has been implemented by google and it has many advantages, while during transitions rom-makers have to adopt and adapt first which is currently ongoing LOS-Side
better search, read and learn because in a short time this will be it until again something new will come out.
the reason why i say all this is because your statement implied that it's something device specific which is only the case as far as newer devices have treble and older devices do not have treble. if you don't like treble and think it's oneplus's fault then you can try another brand but will run dry very soon.
things are not made for us to be easy but to be easy for 99% of the users who don't root and flash custom roms and we have to deal with things as they are, mostly solutions are imminent and in very rare cases there will be none and it's the past.
EDIT: keep in mind that without treble this rom would not even be availble by now and don't get me wrong, of course when possible i as well prefer a recovery flashable "flash and forget" kind of ZIP file
if you prefer that for now i recommend to use one of the Magisk-MOD kind of roms flashed via TWRP over stock rom and if you need a specific feature you can mostly find it in form of an app from the playstore.
you can send me PM if you don't find one and i will assist you how to set it up. this applies to perhaps 80% of all features RR has but not 100 while a smalll part is not possible with notches, i.e. center clock LOL