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Installing Custom ROM on Cubot KingKong Mini

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highbiker

Member
Feb 7, 2021
7
5
Hi,
I have got the Cubot King Kong Mini 2 and I can confirm that exchanging the system to LOS17.1 is possible too.
I did nearly the same as mekkadisu did (#39) for KKM1, but had to do a
Code:
fastboot reboot fastboot
before flashing the system.



This is what I did:
1.) Flash the newer OS for King Kong Mini 2 from King Kong's site using the instructions and flash tool already there (quoted from #39).

2.) Enable developer options by tapping the build number in Settings -> About Phone 7 times, Enable USB Debugging and Allow Bootloader Unlock from developer options (quoted from #39).

3.) (quoted from #39)
Code:
adb reboot bootloader

4.) once in bootloader mode (quoted from #39)
Code:
fastboot flashing unlock

5.) Then confirm unlock on the phone (quoted from #39)

6.) Note the locaton of the vbmeta.img, boot.img and recovery.img files from the stock ROM (quoted from #39)
Code:
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
fastboot flash boot boot.img
fastboot flash recovery recovery.img

7.) Now I did not flash the system directly, but rebooted to fastboot
Code:
fastboot reboot fastboot

8.) After device is in real fastboot mode (the screen is different to that of bootloader fastboot mode)
Code:
fastboot flash system SYSTEM.img

I used the lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img.xz



Why did I do the "fastboot reboot fastboot":
without rebooting to fastboot but direclty flashing the system, I got this error:
Code:
fastboot flash system lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img
Sending sparse 'system' 1/10 (131068 KB)           OKAY [  4.898s]
Writing 'system'                                   FAILED (remote: 'This partition doesn't exist')
fastboot: error: Command failed

After rebooting to fastboot it worked:
Code:
fastboot flash system lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img
Resizing 'system'                                  OKAY [  0.004s]
Sending sparse 'system' 1/5 (262140 KB)            OKAY [ 19.088s]
Writing 'system'                                   OKAY [  4.061s]
Sending sparse 'system' 2/5 (262140 KB)            OKAY [ 19.596s]
Writing 'system'                                   OKAY [  4.036s]
Sending sparse 'system' 3/5 (262140 KB)            OKAY [ 19.943s]
Writing 'system'                                   OKAY [  4.048s]
Sending sparse 'system' 4/5 (262140 KB)            OKAY [ 20.290s]
Writing 'system'                                   OKAY [  3.721s]
Sending sparse 'system' 5/5 (177556 KB)            OKAY [ 13.090s]
Writing 'system'                                   OKAY [  2.879s]
Finished. Total time: 110.773s

I'm not an expert in flashing mobile devices, so I don't know, why I had to to that. I would be very happy if an expert could reply and maybe give me a hint as to what the problem was.
 
Last edited:

highbiker

Member
Feb 7, 2021
7
5
Great, well done!
Why did you choose 17.1 and not 18.1? In my experience it runs better.
LOS18.1 is also flashable to the KKM2. LOS17.1 was my first test. I think I will stay on LS18.1.

I was not able to install TWRP on KKM2. Maybe the original firmwares (KKM vs KKM2) are too different or I'm doing something wrong, but i face the same problem as landsome (see #155). I tried it multiple times using fastboot and SP_Flashtools, but neither worked. Always got bootloops enforcing reflashing of stock firmware via SP_Flashtools.
I used the TWRP from post #33.

My unsuccessful attempts were:

1.) via fastboot. Instead of flashing stock recovery (see 6.) in my post above #163), I flashed recovery_TWRP.img.
2.) via fastboot after "fastboot reboot fastboot" (see 7.) in my post above #163) I got this error
Code:
fastboot flash recovery recovery_TWRP.img
Sending 'recovery' (20056 KB)                      OKAY [  1.211s]
Writing 'recovery'                                 FAILED (remote: 'No such file or directory')
fastboot: error: Command failed
3.) flash via SP_FlashTools I used the following settings:
SP_FlashTools_Settings.PNG
recovery_TWRP.img from post #33.
lk-modified.img: patched lk.img to avoid Orange State (Is working when flashed via fastboot)
vbmeta.img: I tried both, one from post #33 and the original one from stock firmware.

Does anyone have any hint what I might have done wrong? If not, that could indicate that TWRP is currently not working on the KKM2.
 

landsome

Senior Member
May 4, 2015
445
115
LOS18.1 is also flashable to the KKM2. LOS17.1 was my first test. I think I will stay on LS18.1.

I was not able to install TWRP on KKM2. Maybe the original firmwares (KKM vs KKM2) are too different or I'm doing something wrong, but i face the same problem as landsome (see #155). I tried it multiple times using fastboot and SP_Flashtools, but neither worked. Always got bootloops enforcing reflashing of stock firmware via SP_Flashtools.
I used the TWRP from post #33.

My unsuccessful attempts were:

1.) via fastboot. Instead of flashing stock recovery (see 6.) in my post above #163), I flashed recovery_TWRP.img.
2.) via fastboot after "fastboot reboot fastboot" (see 7.) in my post above #163) I got this error
Code:
fastboot flash recovery recovery_TWRP.img
Sending 'recovery' (20056 KB)                      OKAY [  1.211s]
Writing 'recovery'                                 FAILED (remote: 'No such file or directory')
fastboot: error: Command failed
3.) flash via SP_FlashTools I used the following settings:
View attachment 5213069
recovery_TWRP.img from post #33.
lk-modified.img: patched lk.img to avoid Orange State (Is working when flashed via fastboot)
vbmeta.img: I tried both, one from post #33 and the original one from stock firmware.

Does anyone have any hint what I might have done wrong? If not, that could indicate that TWRP is currently not working on the KKM2.

My only guess is that flashing TWRP may not work after having previously done all the other stuff (vbmeta, new OS). It does not make much sense, but given that I have given it almost two dozen tries in every single combination, I am at a loss.
 

birdibird

Senior Member
Apr 9, 2005
368
17
My only guess is that flashing TWRP may not work after having previously done all the other stuff (vbmeta, new OS). It does not make much sense, but given that I have given it almost two dozen tries in every single combination, I am at a loss.
Did you try to start again: flash the original Cubot rom and then TWRP?
 

landsome

Senior Member
May 4, 2015
445
115
Did you try to start again: flash the original Cubot rom and then TWRP?

About half a dozen times. Why half a dozen? Tried with SPF and alternatively fastboot, with and without the rest of the files in the ROOT folder in post #33. Always the bootloop and having to flash AOSP/LOS via fastboot to get out of it. Then back to stock ROM etc.

One thing I did not do, but I don't think I have it in me to try again, is check out some of the older stock ROMs (always tried with the latest).
 

sawasLT

Member
Feb 8, 2021
7
0
Hello , am kinda new here and i want to instal Los to kkm2 but am getting always stuck on
=>Fastboot mode...
and i can not chane nothing , i can not fid the device via
Fastboot devices
or adb devices , i deed to hold power button for 15s
then i can start again with the adb reboot bootloader and after that move am stuck again in the bleck screen on my phone with just
=>fastboot mode...
and i can not do nothing , can some one help :D :D
 

highbiker

Member
Feb 7, 2021
7
5
Hello , am kinda new here and i want to instal Los to kkm2 but am getting always stuck on
=>Fastboot mode...
and i can not chane nothing , i can not fid the device via
Fastboot devices
or adb devices , i deed to hold power button for 15s
then i can start again with the adb reboot bootloader and after that move am stuck again in the bleck screen on my phone with just
=>fastboot mode...
and i can not do nothing , can some one help :D :D
Hi,
it could be a driver issue. Make sure you have installed the correct drivers (see Post #122).
If this was not the problem, make sure your fastboot is of the actual version. Yout can get the actual verison from here:
https://developer.android.com/studio/releases/platform-tools
 

sawasLT

Member
Feb 8, 2021
7
0
Hi,
it could be a driver issue. Make sure you have installed the correct drivers (see Post #122).
If this was not the problem, make sure your fastboot is of the actual version. Yout can get the actual verison from here:
https://developer.android.com/studio/releases/platform-tools

thx for the answer , i updated the drivers and downloaded and used the actual fastboot version but am stil getting the same
looking thru powershell it says

step1
\platform-tools> adb devices
List of devices attached
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
KKMN2201127005290 device

step2
\platform-tools> adb reboot bootloader
\platform-tools>

then it is not showing nothing more ..
the phone is schowing after reboot

=>fastboot mode ... ( on the bottom left corner )
nothing more

Device maniger says:
-adroid phone
-android adb interface
 

highbiker

Member
Feb 7, 2021
7
5
=>fastboot mode ... ( on the bottom left corner )
nothing more

Until here everything is fine. My phone just says "fastboot mode ..." in the bottom left too, after issuing adb reboot bootloader

now your computer should list the device after issuing
Code:
fastboot devices
if not, windows is not recognizing the phone correctly, I think.

My device manager also lists the device as
Android Phone -> Android ADB Interface

At first I also had the problem that my KKM2 was not found via "fastboot devices" in windows.
You have two options now, both are working for me:
1.) Using windows.
2.) Using linux

1.) Windows
I dont know which driver package solved it, but i installed many. Here is a (I hope complete) list of drivers I installed:
  • MTK USB driver v.1.0.8
  • minimal_adb_fastboot_v1.4.3 (There are also drivers included. but be sure to use the current version of fastboot for flashing)
  • WIN8 driver from cubot website (terminated with two failures)
  • MediaTek_Preloader_USB_VCOM_Drivers_Setup_Signed

2.) Linux
If you are familiar with linux, you can try that (linux via virtual box and KKM2 over USB-3.0-Controller (xHCI) is sufficient, I also did that with my KKM2)

in linux you can install fastboot and adb via:
Code:
sudo apt-get update
sudo apt-get install android-tools-adb
sudo apt-get install android-tools-fastboot

linux recognized my kkm2 directly after installing both. So I think additional drivers are also installed by these packages.

but sadly the fastboot version installed by android-tools-fastboot is too old for issuing
Code:
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
so you have to update fastboot to the latest version by using
Code:
mkdir ~/Android && cd ~/Android
wget https://dl.google.com/android/repository/platform-tools-latest-linux.zip && unzip platform-tools-latest-linux.zip
echo "alias adb='~/Android/platform-tools/adb'" >> ~/.bash_aliases && source ~/.bash_aliases
echo "alias fastboot='~/Android/platform-tools/fastboot'" >> ~/.bash_aliases && source ~/.bash_aliases

after that you should be able to do the flashing

But maybe others have have found easier ways. Maybe directly via SP_FlashTool? I didn't found a way to flash the LOS System directly via SP_FlashTool, because the SP_FlashTool does not list a "system" entry (see post #165). Does anybody have a hint here?
 
Last edited:

sawasLT

Member
Feb 8, 2021
7
0
Until here everything is fine. My phone just says "fastboot mode ..." in the bottom left too, after issuing adb reboot bootloader

now your computer should list the device after issuing
Code:
fastboot devices
if not, windows is not recognizing the phone correctly, I think.

My device manager also lists the device as
Android Phone -> Android ADB Interface

At first I also had the problem that my KKM2 was not found via "fastboot devices" in windows.
You have two options now, both are working for me:
1.) Using windows.
2.) Using linux

1.) Windows
I dont know which driver package solved it, but i installed many. Here is a (I hope complete) list of drivers I installed:
  • MTK USB driver v.1.0.8
  • minimal_adb_fastboot_v1.4.3 (There are also drivers included. but be sure to use the current version of fastboot for flashing)
  • WIN8 driver from cubot website (terminated with two failures)
  • MediaTek_Preloader_USB_VCOM_Drivers_Setup_Signed

2.) Linux
If you are familiar with linux, you can try that (linux via virtual box and KKM2 over USB-3.0-Controller (xHCI) is sufficient, I also did that with my KKM2)

in linux you can install fastboot and adb via:
Code:
sudo apt-get update
sudo apt-get install android-tools-adb
sudo apt-get install android-tools-fastboot

linux recognized my kkm2 directly after installing both. So I think additional drivers are also installed by these packages.

but sadly the fastboot version installed by android-tools-fastboot is too old for issuing
Code:
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
so you have to update fastboot to the latest version by using
Code:
mkdir ~/Android && cd ~/Android
wget https://dl.google.com/android/repository/platform-tools-latest-linux.zip && unzip platform-tools-latest-linux.zip
echo "alias adb='~/Android/platform-tools/adb'" >> ~/.bash_aliases && source ~/.bash_aliases
echo "alias fastboot='~/Android/platform-tools/fastboot'" >> ~/.bash_aliases && source ~/.bash_aliases

after that you should be able to do the flashing

But maybe others have have found easier ways. Maybe directly via SP_FlashTool? I didn't found a way to flash the LOS System directly via SP_FlashTool, because the SP_FlashTool does not list a "system" entry (see post #165). Does anybody have a hint here?
thx , the answer war after instaling everithing ... the instalation from " minimal_adb_fastboot_v1.4.3 "
finally found the fastboot device , lets see now gonna try to instal /Los :p
 

sawasLT

Member
Feb 8, 2021
7
0
Hi,
I have got the Cubot King Kong Mini 2 and I can confirm that exchanging the system to LOS17.1 is possible too.
I did nearly the same as mekkadisu did (#39) for KKM1, but had to do a
Code:
fastboot reboot fastboot
before flashing the system.



This is what I did:
1.) Flash the newer OS for King Kong Mini 2 from King Kong's site using the instructions and flash tool already there (quoted from #39).

2.) Enable developer options by tapping the build number in Settings -> About Phone 7 times, Enable USB Debugging and Allow Bootloader Unlock from developer options (quoted from #39).

3.) (quoted from #39)
Code:
adb reboot bootloader

4.) once in bootloader mode (quoted from #39)
Code:
fastboot flashing unlock

5.) Then confirm unlock on the phone (quoted from #39)

6.) Note the locaton of the vbmeta.img, boot.img and recovery.img files from the stock ROM (quoted from #39)
Code:
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
fastboot flash boot boot.img
fastboot flash recovery recovery.img

7.) Now I did not flash the system directly, but rebooted to fastboot
Code:
fastboot reboot fastboot

8.) After device is in real fastboot mode (the screen is different to that of bootloader fastboot mode)
Code:
fastboot flash system SYSTEM.img

I used the lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img.xz



Why did I do the "fastboot reboot fastboot":
without rebooting to fastboot but direclty flashing the system, I got this error:
Code:
fastboot flash system lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img
Sending sparse 'system' 1/10 (131068 KB)           OKAY [  4.898s]
Writing 'system'                                   FAILED (remote: 'This partition doesn't exist')
fastboot: error: Command failed

After rebooting to fastboot it worked:
Code:
fastboot flash system lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img
Resizing 'system'                                  OKAY [  0.004s]
Sending sparse 'system' 1/5 (262140 KB)            OKAY [ 19.088s]
Writing 'system'                                   OKAY [  4.061s]
Sending sparse 'system' 2/5 (262140 KB)            OKAY [ 19.596s]
Writing 'system'                                   OKAY [  4.036s]
Sending sparse 'system' 3/5 (262140 KB)            OKAY [ 19.943s]
Writing 'system'                                   OKAY [  4.048s]
Sending sparse 'system' 4/5 (262140 KB)            OKAY [ 20.290s]
Writing 'system'                                   OKAY [  3.721s]
Sending sparse 'system' 5/5 (177556 KB)            OKAY [ 13.090s]
Writing 'system'                                   OKAY [  2.879s]
Finished. Total time: 110.773s

I'm not an expert in flashing mobile devices, so I don't know, why I had to to that. I would be very happy if an expert could reply and maybe give me a hint as to what the problem was.
hallo ,
am getting the error

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash system lineage-17.1.img
target reported max download size of 134217728 bytes
sending sparse 'system' 1/10 (131068 KB)...
OKAY [ 5.053s]
writing 'system' 1/10...
FAILED (remote: This partition doesn't exist)
finished. total time: 5.063s

i try to do a " fastboot reboot fastboot "

but am geting .

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot reboot fastboot
fastboot: usage: unknown reboot target fastboot

em i stupid and old or am doing something wrong ?

am using the vbmeta boot and recovery from the original rom from the cubot website
 
Last edited:

highbiker

Member
Feb 7, 2021
7
5
hallo ,
am getting the error

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash system lineage-17.1.img
target reported max download size of 134217728 bytes
sending sparse 'system' 1/10 (131068 KB)...
OKAY [ 5.053s]
writing 'system' 1/10...
FAILED (remote: This partition doesn't exist)
finished. total time: 5.063s

thats exactly the error I got and thats why I had to do the fastboot reboot fastboot

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot reboot fastboot
indicates that you are using the fastboot from Minimal ADB, but thats not the actual version. You need the actual fastboot version from here: https://developer.android.com/studio/releases/platform-tools

fastboot --version should print
Code:
fastboot version 30.0.5-6877874
 

sawasLT

Member
Feb 8, 2021
7
0
thats exactly the error I got and thats why I had to do the fastboot reboot fastboot


indicates that you are using the fastboot from Minimal ADB, but thats not the actual version. You need the actual fastboot version from here: https://developer.android.com/studio/releases/platform-tools

fastboot --version should print
Code:
fastboot version 30.0.5-6877874

thx , i managet to instal Los 17.1

now am getting a loat of app stop working and stuf on camera and recorder and sutch
i wanna try to add gapps via adb side loader , hope it will work , thil now guys thx for the help your amazing , last time i was playng around with phones was as i jailbreaked my 3gs to pineapple :D
 

sawasLT

Member
Feb 8, 2021
7
0
now am again with a problem , o downloaded the open_gapps-arm64-10.0-tvmini-20210206.zip
so am in android recovery , going to apply update from adb
in cmd ,

adb sideload open_gapps-arm64-10.0-tvmini-20210206.zip

and am gething the error on my phone screen
E:signature vertification filed
E:error: 21

instal from adb completed with status2.
instalation aborted.
E:fota installation aborted
E:: no such file or directory
E:Fota instalation aborted
E:: bad file descriptor

cmd shows

adb sideload open_gapps-arm64-10.0-tvmini-20210206.zip
serving: 'open_gapps-arm64-10.0-tvmini-20210206.zip' (~47%) adb: failed to read command: No error

sorry if am naggy :D
 

kkm6761

Member
Jan 2, 2021
25
1
A long time, sorry. I am away right now. Don't have anything with me. I'll make a sticky with the main files. There is a TWRP file that does not work. So anyone managed to have both root with magisk and TWRP?



How is KingKong Mini 2 doing with 1000mAh extra battery?
 

highbiker

Member
Feb 7, 2021
7
5
How is KingKong Mini 2 doing with 1000mAh extra battery?

My KKM2 is still on the first battery charge, my experiences are therefore a bit vague. But with a bit of Wi-Fi usage, few GPS-tests, permanently connected via LTE during the day and in flight mode at night, the battery life is about 3 days.
 

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  • 1
    you run leos arm64? i see no arm32 binder64.

    i now yet have resurrection remix, but it drains the battery in 4 hours in airplane mode. so i can't use the phone. i'll then try what you have. there is a rooted version? will xposed work without magisk?
    always A64 (binder) version of course.
    These A64 versions work:

    edit:
    with this script you can install various apps to make the 'full' version if you have the mini version:
    (you will need linux or WSL for bash)

    Telegram support group:
    1
    thanks
    do you mean just skip step with flashing vbmeta, boot and recovery from the manual?
    do i need to run "flashing unlock" command before?
    You only need to flash the new updated rom, nothing else
    1
    thanks
    do you mean just skip step with flashing vbmeta, boot and recovery from the manual?
    do i need to run "flashing unlock" command before?
    Just flash system
    1
    I triyed with adb sideload in order to install Magisk zip file, but did not work because twrp cannot mount system partition.
    which los17 image are you using? It needs to be a rw -> vndklite

    long time ago that I actively used twrp (that was on my kkm1), but just from memory you will need to flash decrypt and factory reset/format data in twrp and flash the system.img with twrp or fastboot or spflashtool afterwards to be able to have twrp access the rom.
    -> this is from memory, so please tell me if I am wrong.
    I flashed this twrp on this device (kkm2) just to test it, and noticed that it could not access my rom as it is encrypted (the original recovery could). I think 3.6.0 should be able to solve that?
  • 7
    UPDATE 2021
    The original post was for the first King Kong Mini, for instructions for the King Kong Mini 2 go to page 9 in this thread:
    https://forum.xda-developers.com/t/...-on-cubot-kingkong-mini.4050815/post-84445303

    ======================

    The Cubot King Kong Mini was released in Q4 2019. It is one of the smallest Android phones on the market with a 4" screen. Like many cheap Mediatek devices, one cannot be sure of how "safe" or "secure" these devices are, so the security/privacy conscious may want to consider installing a custom ROM. Here are the instructions for installing Android AOSP on the Cubot King Kong Mini. Note: I am not responsible for any bricked devices.

    Download the Stock Rom from here and SP Flash Tool just in case you need to reinstall Stock. Download a system image, note you need to use an A/B arm32 image with 64 bindings. For example AOSP 9 is here.

    This process probably can be done with SP Flash Tool but I wasn't able to manage it due to the disable-verification flag required.

    Unzip the stock ROM and reboot the device to bootloader, connect via USB and unlock via:
    Code:
    sudo fastboot flashing unlock

    Note this will erase all data. Then on your computer navigate to the folder with the unzipped ROM (for me was NA_mt6761p_d936p_9101cmp_chuanqi_cc_256gbitp24d3_p_lte_3m-fdd-cs_mul_20191121-210020_songlixin_PC) and type
    Code:
    fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img

    If you do not do this it seems to work without it but then it will bootloop when you try to switch it on. From here on it's standard.
    Code:
    fastboot flash boot boot.img
    fastboot flash recovery recovery.img

    Unzip the .xz image file you wish to use and type:
    Code:
    fastboot flash system SYSTEM.img
    where SYSTEM is the name of whatever image downloaded.


    Root
    For root install magisk manager and you have to patch the recovery to get root (not just boot as flashing boot alone doesn't give you root). So in magisk get it to patch you boot and recovery images and then put those on your computer, go to bootloader and use:
    Code:
    fastboot flash boot magisk_patched_boot.img
    fastboot flash recovery magisk_patched_recovery.img

    You can read more about magisk from recovery here.

    To get root then you need to reboot to recovery, hold power button + volume up and select Recovery. This will appear to boot as normal but you will have root when you do it this way and not when you boot normally. Unfortunately I do not have reception when I do this but do have root, other users have this problem but I have not found a solution.


    Note that I thought I bricked my phone a few times before getting this as nothing would happen after a failed boot and I couldn't switch it on, however what happens is you can't do anything until the battery has almost completely discharged, then when you hit the power button you'll get the no battery sign and when you plug in you can get to Recovery again. This is quite annoying if you've charged it quite high as you'll have to wait a long time to discharge and be tapping on the power button a lot!!


    What doesn't work
    Battery usage doesn't work, this can probably be fixed following this guide. If I get time I will attempt this.

    Other things to note, there is no TWRP yet so I don't have decent recovery options, this also makes it harder to use certain ROMS as you can't flash things like gapps if you install a ROM without it.
    The battery life is definitely worse using AOSP GSI than stock, maybe that vendor overlay would help with that though.

    I hope that helps others.
    5
    Hi,
    I have got the Cubot King Kong Mini 2 and I can confirm that exchanging the system to LOS17.1 is possible too.
    I did nearly the same as mekkadisu did (#39) for KKM1, but had to do a
    Code:
    fastboot reboot fastboot
    before flashing the system.



    This is what I did:
    1.) Flash the newer OS for King Kong Mini 2 from King Kong's site using the instructions and flash tool already there (quoted from #39).

    2.) Enable developer options by tapping the build number in Settings -> About Phone 7 times, Enable USB Debugging and Allow Bootloader Unlock from developer options (quoted from #39).

    3.) (quoted from #39)
    Code:
    adb reboot bootloader

    4.) once in bootloader mode (quoted from #39)
    Code:
    fastboot flashing unlock

    5.) Then confirm unlock on the phone (quoted from #39)

    6.) Note the locaton of the vbmeta.img, boot.img and recovery.img files from the stock ROM (quoted from #39)
    Code:
    fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
    fastboot flash boot boot.img
    fastboot flash recovery recovery.img

    7.) Now I did not flash the system directly, but rebooted to fastboot
    Code:
    fastboot reboot fastboot

    8.) After device is in real fastboot mode (the screen is different to that of bootloader fastboot mode)
    Code:
    fastboot flash system SYSTEM.img

    I used the lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img.xz



    Why did I do the "fastboot reboot fastboot":
    without rebooting to fastboot but direclty flashing the system, I got this error:
    Code:
    fastboot flash system lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img
    Sending sparse 'system' 1/10 (131068 KB)           OKAY [  4.898s]
    Writing 'system'                                   FAILED (remote: 'This partition doesn't exist')
    fastboot: error: Command failed

    After rebooting to fastboot it worked:
    Code:
    fastboot flash system lineage-17.1-20210114-UNOFFICIAL-treble_a64_bvS.img
    Resizing 'system'                                  OKAY [  0.004s]
    Sending sparse 'system' 1/5 (262140 KB)            OKAY [ 19.088s]
    Writing 'system'                                   OKAY [  4.061s]
    Sending sparse 'system' 2/5 (262140 KB)            OKAY [ 19.596s]
    Writing 'system'                                   OKAY [  4.036s]
    Sending sparse 'system' 3/5 (262140 KB)            OKAY [ 19.943s]
    Writing 'system'                                   OKAY [  4.048s]
    Sending sparse 'system' 4/5 (262140 KB)            OKAY [ 20.290s]
    Writing 'system'                                   OKAY [  3.721s]
    Sending sparse 'system' 5/5 (177556 KB)            OKAY [ 13.090s]
    Writing 'system'                                   OKAY [  2.879s]
    Finished. Total time: 110.773s

    I'm not an expert in flashing mobile devices, so I don't know, why I had to to that. I would be very happy if an expert could reply and maybe give me a hint as to what the problem was.
    3
    With KKM2 in TWRP it's impossible to mount system. Because KKM2 is shiped with Android 10 means dynamic partition respectively super partition. Thats a big difference to older android versions, e.g. explaned on youtube. On stock rom at least you can get read-only access to system using magisk. Most other custom roms have su buildin. So changes to /system can only be done "systemless". There is a buildin magisk module for. However it's very inconvenient in comparision to previous android versions (before 10). Is there a way to patch system offline and flash later? E.g. dismantle super.img to system and other partitions, patch the individual things, bundle partitions together back to super.img and flash it to KKM2? At the other hand cubot stock firmware contains system.img but flash tools doesnt flash it, only super.img. Why? What is system.img used for?

    OK, forget system, but how did you manage to access data partition? TWRP can mount data but all files are encrypted. With stock rom I had no success in running an unencrypted data partition. I tried format data with ext4 like descripted here. And I tried to apply DM-Verity Disabler or no-verity-opt-encrypt. But every time I rebooted stock rom, data was encrypted again. Without access to system partition those (old?) scripts wont work anymore. Is there another way for Android 10 (adb sideload, flash tool, ...)? TWRP would be nice for backup and revocery data partition. Have you found other ways for backup data partition? How do I get rid of encrypted data partition? Is this only possible with custom rom?

    Btw KKM2 battery is not like the KKM1! It looks like this. It's a Li-Polymer 3.000mAh battery, named CBT-A061.

    Flash Tool is very nice. With that you can remedy all flashing mistakes and begin from the start, nice phone.
    2
    Upgraded to the 17 April 305 version of CAOS. No echo problems anymore.
    2
    So you have AOSP 11.0 v300.j ? And everything works? That's awesome, I'll try it too

    Yes, everything I use in my daily work is working. Partially better then ASOP 10 ;)

    cubot android 11.jpg