Xiaomi Mi Mix 2S (xiaomi-polaris)
Appearance
	
	
|  | |
| Manufacturer | Xiaomi | 
|---|---|
| Name | Mi Mix 2S | 
| Codename | xiaomi-polaris | 
| Released | 2018 | 
| Type | handset | 
| Hardware | |
| Chipset | Qualcomm Snapdragon 845 (SDM845) | 
| CPU | Octa-core (4x2.8 GHz Kryo 385 Gold 4x1.8 GHz Kryo 385 Silver) | 
| GPU | Adreno 630 | 
| Display | 1080 x 2160 IPS LCD | 
| Storage | 64/128/256GB UFS2.1 | 
| Memory | 6/8GB | 
| Architecture | aarch64 | 
| Software | |
| Original software The software and version the device was shipped with. | Android (MIUI) 8.0 | 
| Extended version The most recent supported version from the manufacturer. | Android (MIUI) | 
| postmarketOS | |
| Category | testing | 
| Mainline Instead of a Linux kernel fork, it is possible to run (Close to) Mainline. | yes | 
| Device package |  device-xiaomi-polaris | 
| Kernel package |  linux-postmarketos-qcom-sdm845 | 
| Flashing Whether it is possible to flash the device with  pmbootstrap flasher. | Works | 
|---|---|
| USB Networking After connecting the device with USB to your PC, you can connect to it via telnet (initramfs) or SSH (booted system). | Works | 
| Battery Whether charging and battery level reporting work. | Partial | 
| Screen Whether the display works; ideally with sleep mode and brightness control. | Partial | 
| Touchscreen | Partial | 
| Multimedia | |
| 3D Acceleration | Works | 
| Audio Audio playback, microphone, headset and buttons. | Partial | 
| Camera | Broken | 
| IR TX | Untested | 
| Connectivity | |
| WiFi | Partial | 
| Bluetooth | Works | 
| GPS | Untested | 
| NFC Near Field Communication | Untested | 
| Modem | |
| Calls | Partial | 
| SMS | Works | 
| Mobile data | Works | 
| Miscellaneous | |
| FDE Full disk encryption and unlocking with unl0kr. | Works | 
| USB OTG USB On-The-Go or USB-C Role switching. | Broken | 
| Sensors | |
| Accelerometer Handles automatic screen rotation in many interfaces. | Untested | 
Yet another phone based on Qualcomm Snapdragon 845 (SDM845).
How to enter flash mode
You have to press + to enter the bootloader.
Installation
1. Run pmbootstrap init and select xiaomi as vendor and polaris as device.
2. Follow the onscreen instruction and configure as your needs.
Sample output:
[10:01:49] Location of the 'work' path. Multiple chroots (native, device arch, device rootfs) will be created in there. [10:01:49] Work path [/home/molly/.local/var/pmbootstrap]: [10:01:49] NOTE: pmaports path: /home/molly/.local/var/pmbootstrap/cache_git/pmaports [10:01:49] Choose the postmarketOS release channel. [10:01:49] Available (6): [10:01:49] * edge: Rolling release / Most devices / Occasional breakage: https://postmarketos.org/edge [10:01:49] * v22.06: Latest release / Recommended for best stability [10:01:49] * v21.12: Old release (unsupported) [10:01:49] * v21.06: Old release (unsupported) [10:01:49] * v21.03: Old release (unsupported) [10:01:49] * v20.05: Old release (unsupported) [10:01:49] Channel [edge]: [10:01:51] Choose your target device vendor (either an existing one, or a new one for porting). [10:01:51] Available vendors (70): acer, alcatel, amazon, apple, ark, arrow, asus, bq, cubietech, essential, fairphone, finepower, fly, goclever, google, gp, hisense, htc, huawei, infocus, jolla, klipad, kobo, lark, leeco, lenovo, lg, medion, meizu, microsoft, mobvoi, motorola, nextbit, nobby, nokia, nvidia, odroid, oneplus, oppo, ouya, pegatron, pine64, planet, purism, qemu, raspberry, samsung, semc, sharp, shift, sipeed, sony, sourceparts, surftab, t2m, tablet, teclast, tokio, tolino, trekstor, vernee, volla, wexler, wiko, wileyfox, xiaomi, xunlong, yu, zte, zuk [10:01:51] Vendor [qemu]: xiaomi [10:01:54] Available codenames (31): aries, armani, begonia, beryllium, cactus, cancro, cepheus, clover, daisy, dior, elish, equuleus, ferrari, gemini, ido, kenzo, laurel, lavender, libra, mido, natrium, platina, polaris, rolex, santoni, scorpio, tissot, vince, whyred, willow, wt88047 [10:01:54] Device codename: polaris [10:01:56] This device has proprietary components, which trade some of your freedom with making more peripherals work. [10:01:56] We would like to offer full functionality without hurting your freedom, but this is currently not possible for your device. [10:01:56] device-xiaomi-polaris-nonfree-firmware: Modem, WiFi and GPU Firmware, also needed for osk-sdl [10:01:56] Enable this package? (y/n) [y]:
$ pmbootstrap flasher flash_kernel $ pmbootstrap flasher flash_rootfs --partition userdata
For FDE:
$ pmbootstrap install --fde
The big list of issues
In no particular order...
Display does not work
- @JoshuaAshton · Feb 5, 2023 10:51am GMT+0100
Looking like the driver for the panel was reverted. The commit is no longer in 6.2-rc3 after the rebase.
- Workaround for display and touchscreen:
https://gitlab.postmarketos.org/postmarketOS/pmaports/-/issues/1894#note_1266158121
Network issues
According to my tests (@Daviteusz), it seems that WiFi works unstable and slow. I tested on a 150/30 fiber network
- 5GHz:
- Network crashes during apk update
- The connection speed is about 6Mbps
- According to speedtest, download pulls 50Mbps, but breaks connection during test
 
- 2.4GHz
- It works better, but sometimes there are similar problems
- Connection speed = 1Mbps
- According to speedtest download pulls max 20Mbps and test passes.
 
Battery charge reporting
- @JoshuaAshton · Feb 5, 2023 10:23am GMT+0100
Battery charge reporting is marked as working on the Wiki, yet /sys/class/power_supply/ is empty. I am guessing there is something much bigger wrong here, perhaps something with the devicetree...?
Community Info
Maintainers
- None
Users owning this device
- Crystalast-29 (Notes: sdm845_5.19 kernel working fine)
- Icenowy
- Illen (Notes: Two devices. One runs mainline, the other runs WoA. Both 6/64 GB.)
- MollySophia
- Notsyncing
- Quandisti
- RiverZhou
See also
- GSMAREHA
- Kernel merge request
- pmaports!3327 Initial merge request