CHUWI Hi9 Air 64GB MT6797 X20 Deca Core 10.1 Inch 2K Screen Android 8 Dual 4G Tablet

[santosst]

I also realized that once I flash TWRP, and nothing else, it's already not possible to book back to system, even if the system is the stock ROM from SPFT. Is there something wrong with this TWRP?

Is your bootloader unlocked? If yes, try to reflash the stock recovery or para partition, because there may be a flag to do a factory reset (and this TWRP is not able to remove this flag)

 

[ULAMSS5]

Is your bootloader unlocked? If yes, try to reflash the stock recovery or para partition, because there may be a flag to do a factory reset (and this TWRP is not able to remove this flag)

Yes, I thought it was necessary to unlock the bootloader to flash TWRP? Is this not the case for this device?

 

[thecoolkid]

Yes, I thought it was necessary to unlock the bootloader to flash TWRP? Is this not the case for this device?

You can also flash it with SPFT

Sounds like you're doing something wrong can you explain step by step, in as much detail as possible, what you're doing?

 

[N3aroo]

hello.
i have problem, i tryed installed AOSP 11, LinageOS17 and always have this sam problem. After instalation i reboot device ( metod install fastboot from cmd) and always i have black screen with "Fastboot mode....". I tryed a few method :/

 

[santosst]

hello.
i have problem, i tryed installed AOSP 11, LinageOS17 and always have this sam problem. After instalation i reboot device ( metod install fastboot from cmd) and always i have black screen with "Fastboot mode....". I tryed a few method :/

Hello!
Double-check if you're installing the A-only version instead of AB. Furthermore, you can try to format data, sometimes the old data can interfere in the boot process.

 

[bjo12]

Hello

I installed lineage os 15 and blissrom

Was able to boot both but my orientation is off for the both of them

My screen is in landscape but the touch function seems to be in portrait

I can't use it properly

Any advise?

Thanks

 

[Imperial.mack]

Anyone have luck with any pen or stylus to draw on pdf files?

 

[amg314]

Hello

I installed lineage os 15 and blissrom

Was able to boot both but my orientation is off for the both of them

My screen is in landscape but the touch function seems to be in portrait

I can't use it properly

Any advise?

Thanks

The 3C Toolbox app allows you to set any orientation (including built in tablet sensor orientation) for any application.

https://xdaforums.com/t/app-4-0-3c-all-in-one-toolbox.2942186/post-56796227

 

[techdimi]

So what is the best rom to use ? Stock rom is outdated, security patches are old. Are there any good compatible roms with more features, better performance, updated security patches etc to replace the stock ?

 

[daitalos]

So what is the best rom to use ? Stock rom is outdated, security patches are old. Are there any good compatible roms with more features, better performance, updated security patches etc to replace the stock ?

Search for GSI / treble 10 or 11 (for example "Phh-Treble AOSP")
https://www.xda-developers.com/flash-generic-system-image-project-treble-device/
https://github.com/phhusson/treble_experimentations/wiki/Generic-System-Image-(GSI)-list

 

[techdimi]

Search for GSI / treble 10 or 11 (for example "Phh-Treble AOSP")
https://www.xda-developers.com/flash-generic-system-image-project-treble-device/
https://github.com/phhusson/treble_experimentations/wiki/Generic-System-Image-(GSI)-list

I know that it is GSI / treble 10 or 11 compatible, the problem is if it worth all the trouble to install such an image and how good it is going to be a generic image comparing to stock without common issues eg. Bluetooth not working, wifi poor performance, battery drain issues etc.

I mean I need to do a lot of reading but does it worth ? Is there an already tested image that works well and it is up to date with security updates this tablet or am I asking too much ?

 

[gumka77]

Any news, any ROMs?

 

[santosst]

I know that it is GSI / treble 10 or 11 compatible, the problem is if it worth all the trouble to install such an image and how good it is going to be a generic image comparing to stock without common issues eg. Bluetooth not working, wifi poor performance, battery drain issues etc.

I mean I need to do a lot of reading but does it worth ? Is there an already tested image that works well and it is up to date with security updates this tablet or am I asking too much ?

- Bluetooth issue is solved through phh Treble settings -> Bluetooth workarounds -> Mediatek
- I didn't face wifi poor performance in any GSI, in fact wifi signal seems weak for me in stock (and I'm in stock rn lol)
- Battery drain is common in A9 and in phh's AOSP. LOS 18 and A11 GSIs based on Lineage OS have a poor battery performance, but is ok in some cases.

From that, I'd reccomend any AOSP-based A11 GSI, like bless, octaviOS or PE (this last one requires repartitioning because the image is really big). A10 GSIs based on LOS are also good, but they are a bit old.

 

[rolfn]

Again: Resizing system partition

My intention was to only enlarge the system partition of my "Hi9 Air" so that relatively large custom ROMs fit in. @santosst and @thecoolkid's posts inspired me to write two Linux shell scripts that do this.

The first script "resize_setup" installs the two binaries "parted" and "mkfs.ext4" on the device and writes two partition lists with MiB and bytes as units ("Hi9Air_partitions_before_MiB.txt" and "Hi9Air_partitions_before_B.txt"). Prerequisite for the next steps are the following entries in "Hi9Air_partitions_before_MiB.txt":
Number Start End Size File system Name Flags ... 29 896MiB 3456MiB 2560MiB ext2 system msftdata 30 3456MiB 3888MiB 432MiB ext4 cache msftdata 31 3888MiB 59600MiB 55712MiB ext4 userdata msftdata ...
If the partitions have different start and end values, "resize_partitions" must be adjusted. A backup of the affected partitions seems unnecessary to me because they will be reassigned by the custom ROM to be installed anyway.

The second script "resize_partitions" deletes the partitions "system", "cache" and "userdata", then creates them again, increasing "system" to 3600MiB. Finally, the partitions are formatted and two new partition lists are written for comparison ("Hi9Air_partitions_after_MiB.txt" and "Hi9Air_partitions_after_B.txt"). See also the comments in the script.

I have successfully tested each of the steps individually and as a whole. Rewriting the Linux shell scripts to Windows batch files seems easy to do.

In the following I was able to successfully install e.g. BLESS and PE. I don't know yet which custom ROM I'll finally install.

 

[rolfn]

After successfully extending the system partition, now I have a serious problem. Apparently PE drains the battery quickly and towards the end my tablet turned itself off. I immediately started charging it. Unfortunately it does not work. After inserting the micro USB plug, a current of about 300mA will flow for a while. Then it rises to approx. 1A and after a while only the few 300mA flow. If I wait longer, the current drops to almost zero. Charging is no longer possible. No type of booting works anymore. I'm desperate! What can I do?

 

[thecoolkid]

After successfully extending the system partition, now I have a serious problem. Apparently PE drains the battery quickly and towards the end my tablet turned itself off. I immediately started charging it. Unfortunately it does not work. After inserting the micro USB plug, a current of about 300mA will flow for a while. Then it rises to approx. 1A and after a while only the few 300mA flow. If I wait longer, the current drops to almost zero. Charging is no longer possible. No type of booting works anymore. I'm desperate! What can I do?

Offline charging doesn't work with GSI's. Boot to system while connected to a charger and charge there and if not possible boot to TWRP and charge there for a while. If the battery drained so that you can no longer boot twrp leave it connected to charger for a few hours, it might recover enough to boot twrp, but never drain your battery completely when using GSI's because you might brick your tablet.

 

[rolfn]

Offline charging doesn't work with GSI's. Boot to system while connected to a charger and charge there and if not possible boot to TWRP and charge there for a while. If the battery drained so that you can no longer boot twrp leave it connected to charger for a few hours, it might recover enough to boot twrp, but never drain your battery completely when using GSI's because you might brick your tablet.

Thank you for your hints. The problem of "offline charging" was previously unknown to me. I kept trying to boot without success. I only succeeded with a trick. I put my tablet in the fridge (about 5 degrees Celsius) for about 2 hours. After several more attempts, I was finally able to boot to TWRP and charging went back to normal.

If I hadn't had any luck, I would have tried the following:

1. Opening the tablet and removing the battery.
2. Charging the battery outside the tablet with an external charger. This "MEGA-IDEA ICHARGER 3.0" is probably a good fit (also available from other retailers).
3. Reinstalling the charged battery into the tablet.

I wonder if there is a chance in the future that the "offline charging" problem for the GSI's can be solved.

Otherwise, thank you again for your tips, which did not let me give up.

 

[thecoolkid]

Thank you for your hints. The problem of "offline charging" was previously unknown to me. I kept trying to boot without success. I only succeeded with a trick. I put my tablet in the fridge (about 5 degrees Celsius) for about 2 hours. After several more attempts, I was finally able to boot to TWRP and charging went back to normal.

If I hadn't had any luck, I would have tried the following:

1. Opening the tablet and removing the battery.
2. Charging the battery outside the tablet with an external charger. This "MEGA-IDEA ICHARGER 3.0" is probably a good fit (also available from other retailers).
3. Reinstalling the charged battery into the tablet.

I wonder if there is a chance in the future that the "offline charging" problem for the GSI's can be solved.

Otherwise, thank you again for your tips, which did not let me give up.

For me when the tablet turns itself off it usually still has enough battery juice for me to be able to connect the power cable and boot into system, but system boot process takes longer in which time the battery still drains so it's risky. Booting into TWRP is faster so good to know. I would advise against putting a tablet into fridge because there might be a build up of condensation on the mainboard and camera lenses.

If the tablet doesn't turn on at all just leave it connected to power for a couple of hours and when the screen turns on and hangs on offline charging screen quickly boot it into twrp and charge a bit before booting the system.

Offline charging issue is just mediatek's and chuwi's fault. It shouldn't rely on system partition at all. There were some attempts for other devices to fix it, but to this day nobody was able to find a fix.

 

[thecoolkid]

Anyone managed to flash and boot latest Magisk 25.2 on a GSI?

Edit:
Nevermind, I had leftover modules making boot imposible xD

 

[santosst]

Again: Resizing system partition

My intention was to only enlarge the system partition of my "Hi9 Air" so that relatively large custom ROMs fit in. @santosst and @thecoolkid's posts inspired me to write two Linux shell scripts that do this.

Nice script, great job!

About the offline charging problem, as @thecoolkid said, there's no fix at this moment, but when I was using custom ROMs, I was used to flash a hugely debloated stock system.img (~300MB) that was not able even to boot to system (and broke my data when I tried to lol), but it was able to boot to offline charging screen. So after charging, I needed to flash or restore the GSI's system image.

Well, if we could do repartitioning, maybe we could create a new partition (a "system_offlinecharging", for example), flash this debloated system.img to this partition and edit boot's fstab in order to assign the system partition to this new partition when booting from offline charging. Not sure if it would work, but maybe we can try it.