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

My Chuwi Hi9 Air is running the _____ ROM?

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Senior Member
May 20, 2014
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.

Do you know how to edit fstab? I know nothing about it, but it might as well be directed toward TWRP without waisting space. Charging in TWRP works fine.


Senior Member
Oct 7, 2020
Sao Paulo
Moto G
Xiaomi Mi A1
Do you know how to edit fstab? I know nothing about it, but it might as well be directed toward TWRP without waisting space. Charging in TWRP works fine.
Oh, maybe TWRP can manage it too, it's a good idea!

About editing fstab, I said something wrong: the file fstab.mt6797 is in vendor/etc. fstab links the physical partitions to mountpoints, like:

/dev/block/platform/mtk-msdc.0/11230000.msdc0/by-name/system /system ext4 ro wait,verify,recoveryonly

This is the first uncommented line in fstab.mt6797; so the partition "/dev/block/platform/mtk-msdc.0/11230000.msdc0/by-name/system", whose format is ext4, is mounted as ready-only (ro) in /system.

I think there's no way to put an if condition in fstab, but maybe we could create a duplicate fstab and change something in the boot process so that the device chooses the duplicate fstab which points to the modified system when booting on charger.

EDIT: I just found this link, and it seems that the right fstab is in another place for Android 8 (our vendor version), not in the vendor partition

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    TWRP 3.2.2-0

    Fully working TWRP 3.2.2-0 (updated on the 03rd of September 2018) based on "O00623 release-keys 20180809" (August 2018 update)

    Download Folder:

    ## TWRP 3.2.2-0 brief installation guide for the CHUWI Hi9 Air (Hi9Air)
    ## Developed and Written by Alberto96 (GearLabs)

    NOTE: For those who want to keep the bootloader locked, follow the SP Flash Tool guide.

    Flashing via SP Flash Tool (noob-friendly):

    1) Download the latest SP Flash Tool software for your preferred OS (Windows/Linux)
    2) Proceed as shown in my guide linked here:

    Flashing via Fastboot (minor skills required):

    WARNING: If your bootloader is not unlocked already, then it is time to do it otherwise you won't be able to flash any custom binary. DO NOT untick the "OEM Unlock" option in the "Developer Options" menu after having flashed the custom recovery.

    1) Reboot into fastboot mode (using the Volume Up + Power keys combo or just by executing "adb reboot bootloader" via ADB or a Terminal on the device)
    2) Execute this command: "fastboot flash recovery recovery.img"
    3) Now you can reboot the device by executing "fastboot reboot" or by long-pressing the power button for a while

    IMPORTANT: Be sure to root your device using Magisk (recommended for SafetyNet) or SuperSU (classic and permanent) right after having installed the custom recovery (before even rebooting into Android!) otherwise, as a security feature, Android will overwrite it with the Stock Recovery thus you will have to repeat the procedure. DO NOT blame the recovery for this since you have been warned.

    // Any procedure shown here has been tested but, obviously, you do it at your own risk. If you don't mess with anything indicated above, the chance to run into issues is almost inexistent. Good luck! //

    Device Tree:
    GearLabs ROM (v3 20180917)

    GearLabs ROM

    This is just a modified Stock ROM containing some improvements and fixes in order to provide the best user experience possible, until GSIs get a proper documentation to replace completely, and properly, the stock software. Basically, this is how CHUWI should have released the software by default.

    Download Folder::

    Please make sure to have the latest August 2018 Stock ROM installed on your device before proceeding.

    Install it via fastboot (fastboot flash boot boot.img & fastboot flash system system.img), remember to unlock the BL first if you haven't already. The installation process may take up to 20 minutes depending on your PC and USB connection stability, then reboot the device (fastboot reboot).
    You can install it via SP Flash Tool too if you use the original scatter file from the Stock ROM if you prefer to keep your bootloader locked.

    What has been changed/improved:
    - Pre-patched using Magisk v17.1 to pass SafetyNet even with the bootloader unlocked
    - 90% of MTK apps have been replaced with better Google variants
    - Most pre-installed Google Apps have been updated to the latest version (mid-September 2018)
    - Removed Adups FOTA updater

    - None noticed, please tell me if there is any.

    Changelog (v3 20180917):
    - Fixed issues with Google Photos
    - Based on the GMS-certified August 2018 release
    - Switched to a proper Pixel boot animation
    - All sounds have been replaced with Google Pixel ones

    Feature requests that require framework modifications won't be accepted, but i am open to any possible improvement if can be made to the ROM.
    NOTE: Before you ask me, no, it isn't possible to reduce the saturation level without major modifications. I won't be touching the vendor partition neither adding any software as a workaround.
    CHUWI Hi9 Air 64GB MT6797 X20 Deca Core 10.1 Inch 2K Screen Android 8..0 Dual 4G Tablet


    Model CHUWI Hi9 Air
    CPU MTK6797 Helio X20 Deca Core 20nm
    A72*2 2.3 GHz
    A53*4 1.4 GHz
    A53*4 1.85 GHz
    GPU ARM Mali-T880 780MHz
    System Android 8.0
    RAM 4GB DDR3
    Capacity 64GB EMMC
    Screen 10.1 Inch IPS Capacitive Screen
    Resolution 2560*1600
    299 PPI Pixel Density
    OGS One Glass Solution Fully Laminated
    Camera Front is 5.0MP Rear is 13.0MP
    Microphone Built-in
    Speaker Built-in
    WIFI 802.11 a/b/g/n/ac(support 2.4GHz and 5.0 GHz)
    Bluetooth 4.2
    GPS Support
    G-sensor Support
    GSM: (Please see pictures below)
    WCDMA: (Please see pictures below)
    OTG Support
    TF Card Support (Maximum support 128G)
    Language Multi-language
    I/O Port 1 x Micro USB port
    1 x 3.5mm Earphone port
    1 x TF card slot(Max Support 128G)
    2 x Micro SIM Card slot
    Battery 8000mAh
    Weight 550g
    Size 241.7*172*7.9mm

    In Box
    1 x CHUWI Hi9 Air Tablet PC
    1 x USB Cable
    1 x Charger
    1 x Adapter (the adapter depends on the country of the buyer.)

    Home page
    Image of Front

    Image of Back

    Image of Buttons

    Chuwi Hi9 Air, Unboxing, Review.

    Review by @Alberto96

    How to Update
    Android Security Updates go to Settings >System >System Update >Check for update
    Wireless Update (OTA) go to Settings >System >About Tablet >Wireless Update >Check for updates >Download >Install now >OK and System reboot.
    Backup NVRAM/IMEI


    How to Flash Stock Rom
    Download and extract stock ROM
    Download and extract flashtool and install mtk driver (disable driver signature enforcement)
    Get rid of any chinese characters in directory names
    Download da file to flashtool directory
    Open flashtool and open da file and open scatter file in stock ROM directory
    Click download
    Plug in powered off tablet
    Wait for ok

    Flash not working? Troubleshoot
    Ignore any errors
    Use flashtool in link
    Get rid of any chinese characters in directory names
    Open and close flashtool a few times before you click download

    How to Root
    There are three ways to root.
    1. Install twrp then install supersu with zip.
    2. Install twrp then install magisk with zip.
    3. Flash magisk modified boot.img.
    How to install Twrp
    TWRP Custom Recovery created by @Alberto96
    SuperSU Download SuperSU TWRP Zip
    Install supersu or magisk with zip file using twrp> install

    Download Magisk TWRP Zip
    MTK Drivers and ADB required
    How to install magisk with modified boot.img ;
    Backup your data, tablet will be wiped
    download patched_boot.img Stock Rom Build number O00623 release-keys 20180506
    OR patched_boot.img Stock Rom Build number O00623 release-keys 20180604
    OR patched_boot.img Stock Rom Build number O00623 release-keys 20180809
    to adb directory in PC
    enable developer options, settings, system, about tablet, build number, tap until developer
    connect cable to pc
    settings, system, developer options, enable oem unlocking
    settings, system, developer options, enable usb debugging
    allow usb devices
    adb reboot bootloader or shutdown and then press power + volume up, select fastboot
    fastboot oem unlock
    press volume up (yes)
    fastboot flash boot patched_boot.img
    fastboot reboot OR cycle power to reboot, erasing device is normal
    restore tablet (copy your data)
    Install latest Magisk Manager
    run magisk manager
    Check for Root with Root Checker
    Your Hi9 Air is rooted with Magisk!

    Time to Boot 30s

    Available space first boot 56.5 GB
    7.47/64 GB MB Used
    Pre-installed bloat NONE!

    How to take a screenshot
    Press Power + Volume Down at the same time.

    Support. Install latest build before requesting support.

    How to enable Split Screen
    Open two apps
    Tap and hold android menu or overview button, select second app
    You can drag the middle point

    Apps tested and working
    Advanced Power Menu [ROOT]
    Control Screen Orientation
    Find My Device
    GMD Immersive (hides soft keys)
    Mr. Number
    Netflix (qHD 960x540)
    Open Camera
    Phone Check
    YouTube (Up to 1440p)


    Antutu Pass 1

    Antutu Pass 2

    3DMark Ice Storm Extreme and Sling Shot Extreme

    Geekbench Single Core

    Geekbench Multi-core

    Geekbench Compute

    Geekbench Battery

    Androbench (Storage Benchmark)


    Home Screen



    2G/3G/4G/LTE Cat 6 Bands (Support for LTE:1/2/3/4/5/7/8/12/17/20/28/38/39/40/41)


    Stock Apps

    Treble Supported but A-System partition only

    Battery Performance Normal Use 7-8 hours

    09/04/2018 I Ordered / pre-ordered
    13/04/2018 New video
    06/05/2018 Received my Chuwi Hi9 Air yesterday Saturday 05/05/18
    10/05/2018 Review posted to youtube see above
    11/05/2018 More pictures and info
    25/05/2018 Link to cases
    04/06/2018 Added links to downloads
    05/06/2018 Added how to flash, how to install magisk and updated known issues
    18/06/2018 Added alternate download link and updated known issues
    20/06/2018 Added TWRP
    01/09/2018 Added links to Build 20180809
    03/11/2018 Added O00623 release-keys 20180905 Update Bugs
    08/11/2018 Download OTA 20181010
    28/11/2018 Download 20181122
    28/11/2018 All CHUWI tablets with Helio X20, X23, X27(or higher verison) will be updated to Android 9.0 in 2019
    14/02/2020 New link to download twrp
    LineageOS 15.1

    This post will be dedicated to all releases. Please read everything carefully before proceeding with the install.


    v0.1 Fastboot ROM:
    v0.2 Fastboot ROM:
    Magisk for Treble:
    Google Apps (choose ARM64 and 8.1, the package variant is up to you):
    The ROM includes my TWRP 3.2.2 by default

    HOW-TO Install:
    1. If you are a Windows User, be sure to have all ADB/Fastboot drivers and tools installed. For Linux, just the tools.
    2. Flash the latest Stock ROM using SP Flash Tool and unlock the bootloader.
    3. Turn on (or reboot, as you prefer) the tablet into fastboot mode (Volume up + Power, a boot menu will appear, choose fastboot mode and confirm with the Volume down button)
    4. Connect it to your PC/Laptop/Whatever (of course)
    5. Run the included script ( for Linux, flash_all.bat for Windows) to start the installation process
    6. Done, the tablet will reboot automatically into LineageOS.
    7. NOTE: If you need Google Apps and/or Magisk, just reboot into recovery mode, wipe data/factory reset, install what you need, and reboot again. No extra steps required in between, just follow the order.

    Current bugs:
    - Animations are not 100% smooth just like the whole UI
    - Default orientation is in portrait mode but the touchscreen and accelerometer will handle it properly
    - Sometimes it glitches during the setup wizard requiring an hard reboot
    - Built-in LineageOS Browser doesn't work
    - Current builds cause a partition size bug (userdata, 4GB only). Please "Format /data" (no wipe) after installation in order to fix it
    - Several issues with Google Apps (Play Services keeps crashing due to library issues). Any variant (like pico, nano...) that doesn't include Webview causes Google Setup Wizard to get into a ~ black screen.

    - Massive performance improvements
    - Enabled FM Radio (untested)
    - Disabled animations by default in order to avoid any possible glitch
    - Fixed Open Gapps Stock package installation bug (no space left message)
    - Other minor fixes here and there

    Additions made to improve the device:
    - Certified Fingerprint to pass SafetyNet (as long as you also install Magisk)




    Following all recent CHUWI products (like the Lapbook Air), this one comes in a eco-friendly packaging with not many accessories included: 1x 5V/2A USB Charger, 1x Micro-USB Cable, 1x Warranty Card and other paperwork.


    Something sure is that CHUWI requires a good translator, since the User Manual says something weird in the title: "The User Manual of Poly nuclear series Tablet PC". Okay...:facepalm:


    The device features a full metal body with a plastic band on the top where antennas and SIM/MicroSD slots are located. From a design prospective, it looks great on the back, but on the front there is a slight loss of space caused by thick bezels. I am noy saying the bezel-less would be better, on a tablet they are required, but just slightly slimmer would have been nicer.


    Its weight is just fine, ~560g, just consider to use it with two hands. Nothing to complain about its thickness, but i would consider to use a case due to the slippery back metal.


    On the front there is the gorgeous 10.1" WQXGA (or wider 2K if you prefer) that looks just excellent except from one thing: the brightness. I read online that its brightness has been limited via software with the latest update. Unfortunately mine was updated out of the box so i can't confirm that, but if that's real, i hope it can be restored via a framework patch to get its full brightness back.

    Anyway, excluding the brightness issue, it looks perfect with great colors (don't trust the photo attached below, reflections destroy it), high pixel density and excellent viewing angles. Also, on the upper center zone, there is a front-facing camera. No sensors (light/proximity) or Notification LEDs are there.


    The upper rear side of the device features the Antenna/Slots area together with a camera sensor supported by a Flashlight. It is possible to use 2x Micro-SIMs and 1x MicroSD, with separate slots for each one.




    As regards the Camera, it is as good/bad as you can probably expect from a Tablet. Even though the rear camera looks, on paper, quite decent, colors are washed-out. It is probably a 8MP camera sensor interpolated to 13MP, but i was not able to get any detail about the sensor so i may add more details later.

    Here are some samples, judge by yourself. Luckily it supports auto-focus so it is possible to get some interesting macro shots.




    I won't be posting any front-facing camera sample since the quality is even worse, barely enough for video-calls.


    The way speakers have been implemented on this device is quite intelligent and never seen before in person. They are positioned on the top, where the charging port and headphone jack are located.

    Quality-wise they are decent, probably identical to what you can get from a smartphone, just doubled since this is a stereo configuration. Perfectly usable in my opinion.


    The microphone instead is located on the side, just below the volume buttons. It works decently, but due to the placement it is easy to get one hand on it.


    GPS & Location

    GPS quality is excellent for a tablet, able to lock satellites almost everywhere with high accuracy.


    Telephony, Mobile Network & WiFi

    The same can't be said for the 4G antenna. For some reason (and this is not an isolated case, just search online to know more), the signal is much lower than what i get on my smartphone, and speed tests definitely confirm that (two different mobile operators tested, same crappy result)


    This is a bit disappoting because unlike other Chinese tablets i have found online, this comes with full 4G bands support for my country (and also others) including Band 20, so not being able to use it properly is not that great. Here you can see all the supported bands, i have the European model.


    Just some extra details about the network cell i was connected too, for geeks.


    Nothing to complain about the WiFi signal reception, pretty average, similar to some smartphones i have reviewed in the past. It is nice to see that it supports WiFi AC networks with speeds up to 433mbps, at least it hasn't been locked via software.


    Battery Life

    Battery Life is OK, the 8000mAh battery can't do miracles in handling such a beefy Chipset and Screen, and the PCMark Battery Life test confirms it (lowest brightness, WiFi on, Sync on).


    It can be probably improved, but not that much. The Helio X20 chipset is known to be a bit power-hungry.

    Something i am not really okay with is the time required to charge the battery. For some reason, even though the Helio X20 chipset supports it, they have not chosen to not enable it, thus you need to wait over 4 hours for a fully charge.


    Software-wise i must say that i am impressed with CHUWI's work. This Hi9 Air runs on Android Oreo 8.0 with Project Treble support (but not Google Certified!), but other than that, it is 100% clean, with no bloatware or custom apps unlike most Chinese tablets.

    The beefy screen resolution is noticeable though while scrolling menus or switching between apps. There is a noticeable lack of smoothness, but it doesn't stutter. Some extra GPU power would have solved this.






    For all benchmark lovers, here you can taste some runs ;)

    Confirming what i have already said before, the GPU power is slightly lacking, but CPU performance can match last-year flagships.









    What to say about this is great but doesn't lack its flaws. Build quality is excellent, the design is pretty good, the screen is awesome and the software is clean. With a few tweaks, it should be possible to make this tablet excellent, except for the 4G antenna that, well, is hardware related.

    Do i recommend it? It depends on what you are looking for and, most important, the possible deal you can find online. If you need a tablet that is able to take great photos, avoid it, otherwise, you can consider it. I will be working on it for dev. and try to squeeze the most out of it.


    Impressive screen quality
    Excellent build quality
    Nice design even if a bit outdated
    Clean software with Treble Support
    WiFi AC support and great GPS signal reception


    Lack of GPU performance for such high resolution
    Limited Screen brightness
    Still Micro-USB and no Quick Charging
    Disappointing 4G signal quality
    Barely usable front-facing camera (and the rear one is not that better)

    Rating: 8.3

    Packaging and Accessories: 7.5
    Design and Materials: 9.5
    Performance and Heat Dissipation: 8
    Screen: 9
    Camera: 5
    Sound: 8
    Battery Life: 8.5
    Software: 10
    OEM Support: ?
    Price: 9

    You can find full-res images (I know, Quality isn't excellent) here:

    Official Website:

    You can buy it on many online shops. Official, and authorized, Retailers are listed in the CHUWI website.