[GUIDE] The correct way to flash custom ROMs

[_Masked_]

Since a lot of people have had trouble flashing Custom ROMs, I decided to create a guide that should work on every device (whether A/B partition or not) except on Samsung devices. For bypassing Decryption Issues, adb sideload the .zip files.

GUIDE

I am assuming you have unlocked your Bootloader, flashed TWRP and have some knowledge on ADB.

[This is known as a clean install or clean flash]

1. Turn off Lockscreen Security
2. Reboot to Recovery
3. Factory Reset
4. Format Data
5. Copy the .zip files from your PC to your phone / Plug in your USB OTG
6. Flash the ROM and then the Recovery Installer (No Magisk/SuperSU after)
7. Reboot to Recovery
8. Flash GApps and Magisk/SuperSU
9. Reboot to System

[This is known as a dirty flash]

To update the custom ROM or fix a error (Bootloop after successful first boot, No Service, etc.)

I am assuming you used my guide to flash the custom ROM

These are basically the same steps but without wiping or formatting data

1. Turn off Lockscreen Security
2. Reboot to Recovery
3. Flash the ROM (has to be the same ROM, updated is recommended, older versions may cause issues) and then the Recovery Installer (No Magisk/SuperSU after)
4. Reboot to Recovery
5. Flash GApps and Magisk/SuperSU
6. Reboot to System

LINKS:

Official GApps Website - GApps Github
Official TWRP Website - TWRP Github
Magisk Forum - Magisk Thread - Magisk Github
Official SuperSU Website - SuperSU Forum - SuperSU Thread - SuperSU Github

I recommend the Nano variant of GApps since I have had no error with it.

Enjoy!

 

[_Masked_]

[Disabler-ONLY]

`This is basically the same guide just if you want to flash Zackptg5's "Universal DM-Verity, ForceEncrypt, Disk Quota Disablers" or any other disabler which requires different steps.

[This is known as a clean install or clean flash]

1. Turn off Lockscreen Security
2. Reboot to Recovery
3. Format Data
4. Copy the .zip files from your PC to your phone / Plug in your USB OTG
5. Flash the ROM and then the Recovery Installer (No Magisk after)
6. Reboot to Recovery
7. Flash the Disabler, Magisk and then GApps
8. Reboot to System
9. Profit

Dirty Flash? You can't. Usually when using a Disabler you have to clean install your custom ROM.

To update use the method in the first post but for step number 5 Flash the Disabler, Magisk and then GApps

 

[dpryor88]

This is a bit much to do. Just use twinnfamous' twrp and you can flash a custom easily. Plus, I flash havoc over crdroid, then back and forth again. So you can flash over. Just have to wipe data and cache after ROM flash and twrp flash then reboot to recovery.

Basically:
Fastboot boot twrp (twinnfamous' 0.7)
Be on 9.0.7 firmware as most custom ROMs use this base right now I think..
Anyway, then flash twrp (twinnfamous' 0.7 installer zip)
Reboot to recovery
Now flash custom ROM
Flash twrp zip
Reboot to recovery
(You'll now be on the opposite slot as before, which means you are on the slot which your new custom ROM was installed)
Wipe > custom > data and cache wipe
Install opengapps nano and magisk 18.0
Reboot system

You'll boot right into the ROM setup screen with no decryption issues along the way as long as you do exactly as I said.

Have fun flashing!

 

[_Masked_]

This is a bit much to do. Just use twinnfamous' twrp and you can flash a custom easily. Plus, I flash havoc over crdroid, then back and forth again. So you can flash over. Just have to wipe data and cache after ROM flash and twrp flash then reboot to recovery.

Basically:
Fastboot boot twrp (twinnfamous' 0.7)
Be on 9.0.7 firmware as most custom ROMs use this base right now I think..
Anyway, then flash twrp (twinnfamous' 0.7 installer zip)
Reboot to recovery
Now flash custom ROM
Flash twrp zip
Reboot to recovery
(You'll now be on the opposite slot as before, which means you are on the slot which your new custom ROM was installed)
Wipe > custom > data and cache wipe
Install opengapps nano and magisk 18.0
Reboot system

You'll boot right into the ROM setup screen with no decryption issues along the way as long as you do exactly as I said.

Have fun flashing!

You wasted that post just for this? I assure you that my tutorial guarantees success when using a official or unofficial version of TWRP or custom ROM, I also used the method you posted about but it did not work. Also what do you mean by "9.0.7"?
The GApps version you use doesn't have to be Nano and Magisk doesn't have to be v18.0. I'm sure you just copy-pasted this, my method should always succeed. The TWRP doesn't have to be from @twinnfamous , it can be from any developer. This is not a OnePlus 6T only guide.

 

[Ashwinrg]

This flashing process is difficult in my view. Why are you making the simple custom rom flashing process so difficult for the noobs.

 

[dpryor88]

You wasted that post just for this? I assure you that my tutorial guarantees success when using a official or unofficial version of TWRP or custom ROM, I also used the method you posted about but it did not work. Also what do you mean by "9.0.7"?
The GApps version you use doesn't have to be Nano and Magisk doesn't have to be v18.0. I'm sure you just copy-pasted this, my method should always succeed. The TWRP doesn't have to be from @twinnfamous , it can be from any developer. This is not a OnePlus 6T only guide.

Why are you angry? Haha.

And you linked this from the op6t forums so I'm commenting on that phone. And that's how it's done on that phone. And it does matter which twrp you use for THAT phone because one doesn't decrypt correctly.

Copy and paste? No... And nano is always best if you read xda basically anywhere. Not that I said you HAVE to use nano anyway.. it was just in my steps. And that works for me with any/every ROM. So don't be so opposed to other suggestions. Your method is really weird and involves way too much use of a computer/fastboot. Kind of defeats the purpose of using twrp, don't you think?

 

[raiderep]

This flashing process is difficult in my view. Why are you making the simple custom rom flashing process so difficult for the noobs.

What is making it difficult is encryption/decryption not working right in twrp yet (just a guess). I was having a hell of a time getting anywhere myself and kept getting my storage all jumbled from encryption until I found this thread which put it together for me with the adb sideload part, that bypasses encryption or at least lets you flash what you want when the folder names get all wonky.

Thanks OP for laying it out so clearly for me, I am an old dinosaur that was hesitating on messing with this a/b nonsense until I got my 6T and got the itch again. My trusty dusty nexus 6 is so much easier but it's also been around and has one system and a solid twrp for it.

Cheers! :good:

 

[_Masked_]

What is making it difficult is encryption/decryption not working right in twrp yet (just a guess). I was having a hell of a time getting anywhere myself and kept getting my storage all jumbled from encryption until I found this thread which put it together for me with the adb sideload part, that bypasses encryption or at least lets you flash what you want when the folder names get all wonky.

Thanks OP for laying it out so clearly for me, I am an old dinosaur that was hesitating on messing with this a/b nonsense until I got my 6T and got the itch again. My trusty dusty nexus 6 is so much easier but it's also been around and has one system and a solid twrp for it.

Cheers! :good:

Sorry for the late reply, but yes this is for bypassing TWRP Decryption issues.

 

[ayed78]

Since a lot of people have had trouble flashing Custom ROMs, I decided to create a guide that should work on every device (whether A/B partition or not) except on Samsung devices.

GUIDE

I am assuming you have unlocked your Bootloader, flashed TWRP and have some knowledge on ADB.

[This is known as a clean install or clean flash]

1. Turn off Lockscreen Security
2. Reboot to Recovery
3. Format Data (Wipe)
4. Flash ROM and then the Recovery Installer (No Magisk after)
5. Reboot to Recovery
6. Go to Advanced, ADB Sideload then sideload GApps, the Recovery Installer and Magisk
7. Reboot to System
8. Profit

I recommend the Nano variant of GApps since I have had no error with it.

Enjoy

this step means need do with pc not by twrp

 

[_Masked_]

this step means need do with pc not by twrp

This is to bypass Decryption issues.

 

[_Masked_]

This flashing process is difficult in my view. Why are you making the simple custom rom flashing process so difficult for the noobs.

I mean I could make a tool for flashing a custom ROM but I'm sure that there's a tool for that already.

 

[_Masked_]

bump. (ignore)

 

[Krullendhaar]

1. Turn off Lockscreen Security
2. Reboot to Recovery
3. Factory Reset
4. Format Data
5. Copy the .zip files from your PC to your phone / Plug in your USB OTG
6. Flash the ROM and then the Recovery Installer (No Magisk/SuperSU after)
7. Reboot to Recovery
8. Flash GApps and Magisk/SuperSU
9. Reboot to System

So when are we required to wipe system in addition to just a factory reset? And when do we need to format data?

 

[_Masked_]

So when are we required to wipe system in addition to just a factory reset? And when do we need to format data?

Just follow the steps, in order.

 

[I5WsRcGXFSPHLBFtjNxBXkd2]

Hi.

What if I want to flash a custom kernel on a clean Rom flash? When should I do it? Together with Magisk and Gapps?

 

[Santi3598]

What do you mean by "Recovery Installer"? That's the only thing I don't understand.

Thank you for this guide.

 

[Gabrech]

What do you mean by "Recovery Installer"? That's the only thing I don't understand.

Thank you for this guide.

Same here, I do not understand why I should flash a recovery img when twrp does seem to stay installed after flashing everything. Maybe the custom rom I use does include twrp ?

 

[elenaaustin87]

Custom rom means bugs, possible privacy leak and overall less polished. Developer that are working on them are fantastic but they are most of the time nowhere near as what offer the stock one.

What you need is to check adb, doesn't need root but you can still remove apps (even system one) and do more tweaks.

If needed, check how to patch boot image with magisk, it works on all phone and get you root.

With that, you're free to debloat your device.

 

[Gabrech]

Hey just one little question: is it ok to dirty flash with encrypted data folder ?

 

[Waweo]

What do you mean by "Recovery Installer"? That's the only thing I don't understand.

Me neither, is it safe to assume that the step can be left out if TWRP is already there and I use it to flash the ROM?

Thank you for this guide.

+1