Beware! This is currently at
beta status and only three people have successfully tried this so far.
While I have tried to ensure this works for anyone, this
may fail. The result of a failure could include voiding of warranty and
hardware damage.
As preparation, I would like folks to be familiar with LGUP/LGBridge and
how to use them. Using LGUP is also how to get back to stock. On the H990DS Bluetooth is implemented via kernel module and the kernel module has to be loaded off /system, therefore there is no choice but to write to /system.
Step 2 of DirtySanta retrieves the files "abootbackup.img", "bootbackup.img" and "recoverybackup.img".
Save these files! I'm not 100% certain, but I
suspect "abootbackup.img" may need to be restored before doing full LGUP.
For the most part the steps are identical to the
classic DirtySanta, but a few of the files are different.
Once you get to step 3, the procedure is different.
First, the TWRP image is different, use
this one instead, which targets the H990.
Instead of running step3.sh/step3.bat; instead run the command `fastboot flash recovery twrp-3.0.2-1-h990.img`,
then repeat this command (apparently the debug bootloader is unreliable with this command). After this run the command `fastboot reboot`, then follow the directions for getting into TWRP. Instead of running step3.sh/step3.bat, unpack the attached step3_h990.zip and run step3_h900.sh if on OSX/Linux/FreeBSD/Unix or click on step3_h990.bat if on Windows.
After step 3, do not do the `fastboot flash boot bootbackup.img` step. Instead flash the attached zip (a specially modified kernel targeting the H990DS) during the same step as flashing SuperSU.
Likewise "boot1.img" and "boot2.img" should also be
ignored. Those are for DirtySanta with the US V20 models, and
not the H990DS.
After step 3, boot in to TWRP. Press and hold volume DOWN; press and hold power until the LG logo comes up, then briefly release power (0.5-1.0sec) and then hold power again. You will then be prompted "Delete all user data (including LG and carrier apps) and reset all settings?", select "Yes" twice and as long as TWRP installation was successful you'll get into TWRP and no reset will be done.
Inside TWRP flash the attached h990ds-kernel.zip and then flash SuperSU.zip. At this point the process
should be complete. There won't be static on boot, you'll have root and nothing else should have changed.
Warning: This is at beta testing state and could well brick your device. No warranty is provided, use at your own risk (though I certainly hope nothing will go wrong).
These directions are
likely very poor quality, if you're not well experienced with shell prompts and all the tricks that can be done, please wait. This kernel is also
exclusively for the H990DS, if you've got
any other model, stay away. The H990N (single-SIM) will
not work, though you could have an interesting experiment.
Folks who haven't done a lot of experimentation, please hold off until experienced people have confirmed this works. There is a
lot that could go wrong.
I believe I have fulfilled the condition for the bounty.
Thanks to:
@me2151 the original DirtySanta bootloader, crucial for this to work
@thubble for figuring out the last bit of the modem and (successful) guinea pig #2
@USA-RedDragon for making everyone aware of LineageOS's source tree
@exadeci (successful) guinea pig #1
MD5: 5182bc528db03c2848c591f809a65564
SHA160: 14bd8f2714fd652b259b6a60407d071dbf672809
SHA512: dc049ab1e83a51a40e59d7871e1b122559836c1df13b2f7104f13d2cf82d3eb7ca767def108d267d56ae90e7ee58c5f3fc95d60af638a492cb113a982bf64315