Ubuntu Linux 18.04.1 on the Chuwi Hi10 Pro

I'm collecting all the bits and pieces here that are needed to run Ubuntu 18.04.1 on the Chuwi Hi10 Pro.

My device:

• Chuwi Hi10 Pro
• HQ64 series, CPU Atom x5-Z8350
• serial number HQ64G421709xxxxx
• BIOS version P1D6_C109D_B.237 x64
• Ubuntu 18.04.1, stock HWE kernel 4.18

Installation

• Create USB install stick with Ubuntu 18.04.1
• To boot from an external medium, press F7 when the CHUWI logo appears.
• After installation, reboot and hit F7 again, then select "ubuntu".
• If boot hangs with "Started user manager for UID 120" (or similar):
  • Switch to text console with Ctrl-Alt-F4
  • Edit /etc/gdm3/custom.conf
  • Set WaylandEnable=false

Linux/Android Dual-Boot

This part is especially tricky, since there are so many poorly- or un-documented bits and pieces involved.

The built-in touch-enabled boot selector just seems to check for two files on the EFI System Partition:

• /EFI/BOOT/bootx64.efi for Android (identical to /loader.efi on the default EFI layout)
• /EFI/Microsoft/Boot/bootmgfw.efi for Windows

Consequently, after Windows has been replaced by Ubuntu, copying the /EFI/ubuntu/ folder to /EFI/Microsoft/Boot/ and renaming shimx64.efi to bootmgfw.efi allows booting Linux via the Windows boot selection entry.

Unfortunately, this still causes the Android install to hang on boot after Linux has been installed. I was assuming, for a very long time, that this is also an EFI-related problem. However, after multiple factory resets (see https://forum.chuwi.com/thread-2341-1-1.html and https://01.org/node/2463 for instructions), I finally found out that the problem is related to the very eager Ubuntu automounter, which grabs any ext4 filesystem it can find and mounts it read-write.

Of course, this shouldn't be a problem in theory, but this also happens for the Android system/data/etc. partitions, and whatever Ubuntu does to the ext4 FS when it's mounted, causes Android to croak. This means that even just booting a Ubuntu Live System from USB one single time will likely render the Android installation unbootable.

I've finally managed to fix this by setting the respective UUIDs to noauto in /etc/fstab as follows:

# do _not_ automount the Android partitions
UUID=57f8f4bc-abf4-655f-bf67-946fc0f9f25b  /none ext4 ro,noauto 0 0
UUID=57f8f4bc-abf4-655f-bf67-946fc0f9f25b1 /none ext4 ro,noauto 0 0
UUID=57f8f4bc-abf4-655f-bf67-946fc0f9f25b2 /none ext4 ro,noauto 0 0
UUID=57f8f4bc-abf4-655f-bf67-946fc0f9f25b3 /none ext4 ro,noauto 0 0

If you look closely, you will notice that entries 2-4 are not actually proper UUIDs, they have an additional digit from 1-3 at the very end. The reason for this is that all the Android partitions (system, cache, data, config) have the same UUID and show up with the extra digit when the automounter grabs them. I'm not sure if this UUID duplication might actually be the root cause...

As a hotfix, when booting from a live USB stick, you can also add systemd.mask=udisks2 to the kernel commandline.

Hardware

GPU

Intel HD Graphics - works out of the box, accelerated FullHD videos in Youtube on Firefox play smoothly.

Backlight Control

Works OOB on 4.18 (not on 4.15, see https://bugs.freedesktop.org/show_bug.cgi?id=96571)

WiFi

RTL8723BS - works out of the box, easily getting 4 MB/s downloads. No complaints.

Suspend

Works out of the box, pleasant surprise :-)

Screen rotation

Works (surprisingly) out of the box. Thanks systemd ;-)

Audio

Headphones work wih the UCM files from alsa-lib-1.1.6 (see sound/). Speakers need some GPIO tweaking (see https://github.com/danielotero/linux-on-hi10/issues/8 for details).

Touchscreen

Silead MSSL1680

• copy mssl1680.fw from this repo into /lib/firmware/silead/.
• Calibration: use https://github.com/reinderien/xcal to get xinput calibration matrix, say n to "Use rotation?"
• ye olde xinput_calibrator won't work anymore
• xinput --map-to-output silead_ts DSI-1

Bluetooth

RTL8723BS - rather annoying, seems to require kernel patch + some custom hciattach? Since this is being worked on, I may just use an USB Bluetooth dongle in the dock for the moment. Proper solution seems to be on track for kernel 4.19 or maybe 4.20: https://patchwork.kernel.org/cover/10553793/

• https://github.com/lwfinger/rtl8723bs_bt (custom hciattach + FW)
• https://github.com/jwrdegoede/linux-sunxi/commit/95440719e05c790f1bd91ed459708df476c7fdd3 (hacky kernel patch)
• https://raw.githubusercontent.com/Manouchehri/vi8/master/Ubuntu_support_files/rfkill.patch (rfkill tweak)

Cameras

Will probably be enabled when CONFIG_INTEL_ATOMISP matures (Atom Imaging Signal Processor). However, this may take quite some time: https://bugzilla.kernel.org/show_bug.cgi?id=109821

USB Connectors

Charging via USB-C connector works.
Micro-USB connector untested.

Micro HDMI Connector

Untested.

Sources:

• Generic tips: https://github.com/danielotero/linux-on-hi10
• Similar HW: https://wiki.gnome.org/BastienNocera/Ondav975w
• Generic tips: https://jonathansblog.co.uk/hardware-hacking
• Factory restore: https://forum.chuwi.com/thread-2341-1-1.html
• Generic tips: https://txlab.wordpress.com/2017/03/11/running-ubuntu-on-chuwi-hi10-pro-tablet/
• Touchscreen FW: https://github.com/onitake/gsl-firmware/tree/master/firmware/chuwi/hi10_pro-z8350
• Factory images: https://forum.chuwi.com/forum.php?mod=viewthread&tid=2341
• Russian forum: https://w3bsit3-dns.com/forum/index.php?showtopic=769658&st=5160

Additional Notes

(supposed) BIOS reset procedure, found in Russian forum:

• Turn off the tablet.
• Hold the power key for 15-20 seconds.
• Release the button for 10-15 seconds.
• Turn it on as usual.
• All BIOS is reset to default.