[LG V20 Guides, News, & Discussion] xdav20:
[MENTION=6984210]emdroidle[/MENTION]

Thank you very much for your recent detailed responses, much obliged. I know, and like, your strategy with your kernel development. Should LG completely halt the firmware development for LG v20 then your kernel would be our only lifeline with those security patches we would be desperate for. Your strategy will pay off in a long run. However, for now the USB connection issue that crashes the system is my biggest problem. I'm prepared to test your recent release if you have done something for that. Thank you for all your hard works.

[MENTION=1657835]jahlex[/MENTION]

Since everything works on a 100% Stock Kernel, when something goes wrong after a custom kernel installation, naturally, the blame put on the custom kernel and a custom kernel has never been perfect either. I will try to make an awareness right below this comment. I look forward to the upcoming releases. Thank you and [MENTION=4394458]Leicxan[/MENTION] for all the hard works too.

[MENTION=3274558]h99[/MENTION]0DS Owners

If you wish to avoid future problems please read this section. From this point on there will be two custom kernels for our device, one from a joint venture by [MENTION=1657835]jahlex[/MENTION] & [MENTION=4394458]Leicxan[/MENTION] and one from [MENTION=6984210]emdroidle[/MENTION]. The very important point in this message is, you have to pick one over the other and stick by it. Technically, you cannot flash one over the other without facing issues at one point or soon after.

To test a kernel follow these steps please:

1. Backup the firmware

2. Factory Reset, Format Data, Boot Recovery

3. Restore the backup you made right after installing recovery. The firmware version should be 10b/10c with stock boot image. This is your lifeline (95%) after your fitmware starts acting up. If you don't have one, I highly recommend to restart again so you can make a backup copy.

4. Reboot recovery, don't be lazy now please

5. Upgrade to 10g/10j by kdzwriter method. Since the entire boot image is 100% stock at this stage, you can use -ak flag to ensure the system version matches the kernel version. Only the ramdisk is from 10b/10c version after kdzwriter. [MENTION=6984210]emdroidle[/MENTION], if -b flag to be enabled after restoring a 100% stock, 10b/10c in this case, it would be possible to flash the entire boot image by kdzwriter without any issues.

6. Reboot recovery for a good measure, don't be lazy now please

6. Install the custom kernel, install your choice of SU

7. Reboot system

About TWRP recovery

The only recovery we can use to install custom kernels is v3.0.2-1. The latest version is elsa v3.1.1-0 and you cannot install custom kernels with this recovery version, unless something has changed and I wasn't aware of it. You have to remember that after wipping /data partition TWRP recommends to restart the recovery. I would like to think, after a major change to a partition this is a good practice to reboot the recovery so it can be aware of the applied changes.

Restoring back to 10g/10j after testing a custom kernel that you didn't like:

1. Factory reset, Format Data, Reboot Recovery

2. Restore 10b/10c backup, Reboot Recovery

3. Restore your 10g/10j, Reboot to system. No need to install a custom kernel or SU as this one have them all.

Notes:

Depending on what the custom kernel installation, inadvertently, does you might be unable to restore anything and in the best scenario you can flash a kdz firmware by LGUP or at worse LGUP will not recognise your firmware as H990DS or cannot connect to it.

Flashing an untested custom kernel should be done only by those have enough experience in recovering from a bad flash. Please don't assume, by flashing back the last good kernel everything will be okay "every time".

Because of existence of multiple kernels for our device, you must know what kernel any given TWRP backup has when restoring it. Therefore, as a good practice include the info in your backup names.