[H815EU _ONLY_] Relock BL cust/misc/persistent.img preemptive dump

[jskasia]

@OllieD, as the OP mentioned, actually when you change from 'dump' to 'flash' command, you will need to change from 'skip' to 'seek' as well.

 

[blake_spector]

So, for a clean "starting point" I flashed v20j using LGUP over the v20g that was installed. Basically because that was a KDZ quick to download (LG servers) and something that is fresh, proper and working on H815EUR devices.

Next I will dump the partitions in question, unlock via official LG unlock.bin and try to relock.
Stay tuned and happy holidays!

 

[Minto107]

So, for a clean "starting point" I flashed v20j using LGUP over the v20g that was installed. Basically because that was a KDZ quick to download (LG servers) and something that is fresh, proper and working on H815EUR devices.

Next I will dump the partitions in question, unlock via official LG unlock.bin and try to relock.
Stay tuned and happy holidays!

Can't wait to hear about results! I'm on v20g right now, didn't touch a thing but if you'll be able to get relock working on marshmallow I'm in for unlocking(thank God that my H815EU is unlockable)

Wysłane z mojego LG-H815 przy użyciu Tapatalka

 

[letama]

Well, just did the test, I confirm that it works! (at least on my device)

I was able to relock without any issue.

Good news also, I did dd back the partitions backup I did after unlock, it does re-unlock the bootloader without factory reset. That's great!

 

[ObiDanKenobi]

Which partitions did you dd? Misc, cust and persistent only?

---------- Post added at 02:30 PM ---------- Previous post was at 02:27 PM ----------

Better still, please post the commands to lock and the commands to unlock.

 

[letama]

Which partitions did you dd? Misc, cust and persistent only?

I only did misc, persistent and drm partitions. I didn't bother with cust, I do have a full backup if needed.

****
disclaimer: you can brick permanently your device with this!
This is for my device with my partition layout, I can't be sure that your device has the same one
****


Here are the commands I used to relock (H815 EUR/FRA):

dd if=/data/media/0/BL/misc_pre.ext4 of=/dev/block/mmcblk0 bs=512 seek=262144 count=32768
dd if=/data/media/0/BL/persistent_pre.ext4 of=/dev/block/mmcblk0 bs=512 seek=380928 count=4096
dd if=/data/media/0/BL/drm_pre.ext4 of=/dev/block/mmcblk0 bs=512 seek=655360 count=16384

the _pre.ext4 were stored in internal storage in a BL directory.

_pre files were done from the full backup (pre_unlock.dmp) I did before unlocking with these commands on PC:

dd if=pre_unlock.dump of=misc_pre.ext4 bs=512 skip=262144 count=32768
dd if=pre_unlock.dump of=persistent_pre.ext4 bs=512 skip=380928 count=4096
dd if=pre_unlock.dump of=drm_pre.ext4 bs=512 skip=655360 count=16384

I took the pre_unlock.dump directly from device in flash mode with:

dd if=/dev/block/mmcblk0 of=/data/media/0/pre_unlock.dump bs=512 count=12419072

You have to chmod/chown it to be able to access it afterwards:

chmod 666 /data/media/0/pre_unlock.dump
chown media_rw:media_rw /data/media/0/pre_unlock.dump

(these two are from memory, I didn't capture the log)

Again, be very cautious with the dd commands!

 

[blake_spector]

Well, just did the test, I confirm that it works! (at least on my device)

I was able to relock without any issue.

Good news also, I did dd back the partitions backup I did after unlock, it does re-unlock the bootloader without factory reset. That's great!

That's great news! Thanks so much for your help! :good::good:

 

[blake_spector]

Which partitions did you dd? Misc, cust and persistent only?
---------- Post added at 02:30 PM ---------- Previous post was at 02:27 PM ----------
Better still, please post the commands to lock and the commands to unlock.

I will put all the information gathered here in a "guide" when i perform the procedure on my device.
I will try to record it on video with screencapture. . . from locked, send_command.exe on MM, dumping the partitions, unlocking with unlock.bin and relocking it again with the prior saved data.

 

[letama]

I think i found a little typo there (count is not divided by 8 for 4096 blocksize) :angel:

Oups, you're right, this is for a 512 block size . I'm editing the post.

 

[kingtm]

Hello and Merry Christmas to all. I have a question for you. Will it be possible is to lock the bootloader on unlocked phones?

Изпратено от моят LG-D855 с помощта на Tapatalk

 

[Minto107]

Hello and Merry Christmas to all. I have a question for you. Will it be possible is to lock the bootloader on unlocked phones?

Изпратено от моят LG-D855 с помощта на Tapatalk

Nah I don't think so. We're using partitions from locked phone to lock it again, ppl who unlocked without dumping their partitions can't relock

Wysłane z mojego LG-H815 przy użyciu Tapatalka

 

[Engelm]

You can Try to compare some Partitionen Front different phones.
Maybe there is a pattern you could find....

 

[JoHnNy08PL]

Great! More and more people reporting success with locking bootloader! So I guess it is now confirmed that European H815 can be relocked. A nice Christmas present

 

[petro_ionut]

Interesting because it did not work for me.

Something in the commands is wrong, I assure you that it has to work, did it 2 times!

Sent from my LG-H815 using Tapatalk

 

[dnkncht]

Also can confirm it works!


But the next day it ran into the Bootloop-issue. I were be able to relock it.
Already called LG, I'll get a replacement...

 

[uio88]

Hello, blake_spector can recapitulate all the passes for relock bootloader of H815Eu? Thanks in advance

 

[blake_spector]

Hello, blake_spector can recapitulate all the passes for relock bootloader of H815Eu? Thanks in advance

Sure, will post a video with all the steps tomorrow or the day after.

 

[uio88]

Thank you my friend. Happy holidays!

 

[jskasia]

One more thing, could someone who successfully relock their bootloader post the pre-lock and post-lock partion images here ? So that we could help together to figure out the changes.

If there are more than one device posted, we could find out if unlocking of two phones result the same or not. :laugh:

 

[petro_ionut]

Nah I don't think so. We're using partitions from locked phone to lock it again, ppl who unlocked without dumping their partitions can't relock

Wysłane z mojego LG-H815 przy użyciu Tapatalka

I think will it work, but you need the partitions and try!

Sent from my LG-H815 using Tapatalk