Things are changing with the advent of project treble and seamless updates. OnePlus will no longer release ROMs flashable via stock recovery (with twrp is possible but not recommended). The updates will be done on the slot not used for example if you are using slot a the update will be installed on slot b and the slot b will be set as default. If you brick and you are in bootloop how you can restore the rom? You can't with Stock ROM you have, because the zip can be only installed via Update Engine, so what can you do? Flash a stock rom via fastboot. I have extracted all images from the stock zip and i have made a new zip with the Fastboot ROM with a flash-all.bat included. This will work only if your bootloader is unlocked. This will erase all your data and will wipe your internal storage.
HOW TO FLASH
Download the zip;
Unpack the zip in a folder;
Reboot the OnePlus 6 in fastboot mode (Power and volume-);
Connect the OnePlus 6 to PC;
Run flash-all.bat flasher you need;
Wait until the process end;
The phone will automatically reboot.
FLASHER ADVANCED GUIDE
DOWNLOAD
All roms on AFH:
https://www.androidfilehost.com/?w=files&flid=271877
All roms on Sourceforge:
https://sourceforge.net/projects/fastbootroms/files/OnePlus 6/
MANUAL FLASH: Windows - OSX - Linux
If you want to manual flash these roms these are the commands (you need to extract images.zip before proceed)
Fastboot Partitions:
If you need also persist partition, this is the command:
Criticals Partitions, for these you need to boot the TWRP:
When you are in TWRP you need to run these commands to push and flash all criticals partitions:
REMEMBER
"Invalid sparce file format at header magic" is not an error, you need to wait a bit when you see that string, just wait.
These ROMs can't be used to update or downgrade your phone but just to restore your phone, so don't use them to come back to oreo or to update from oreo to pie.
If you want to rebrand your phone from HydrogenOS to OxygenOS you can follow this guide:
Rebrand Guide
If you want you can use also my tool to flash Factory Images, unlock bootloader, flash twrp or to understand if the device is recognized:
https://toolaio.tk/
Thanks to
@SaiBork for first time tested
If you got some problems like write error or no partition, check this:
https://forum.xda-developers.com/showpost.php?p=76658555&postcount=34
DONATE LINK
If you want to support this and others my projects please consider making a donation, thanks.