Xiaomi Redmi Note 8T (xiaomi-willow)
![]() Redmi Note 8T running firefox and weston-smoke (kapton tape holding UART in place) | |
Manufacturer | Xiaomi |
---|---|
Name | Redmi Note 8T |
Codename | xiaomi-willow |
Released | 2019 |
Hardware | |
Chipset | Qualcomm SDM665 Snapdragon 665 |
CPU | Octa-core (4x2.0 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver) |
GPU | Adreno 610 |
Display | 1080 x 2340 IPS LCD |
Storage | 32GB, 64GB, 128GB |
Memory | 3GB, 4GB, 4GB |
Architecture | aarch64 |
Software | |
Original software | Android 9, MIUI 10 |
postmarketOS | |
Category | testing |
Pre-built images | no |
postmarketOS kernel | 4.14.117 |
Unixbench Whet/Dhry score | 4168.2 |
Flashing |
Works |
---|---|
USB Networking |
Works |
Internal storage |
No data |
SD card |
No data |
Battery |
No data |
Screen |
Partial |
Touchscreen |
Works |
Multimedia | |
3D Acceleration |
Broken |
Audio |
No data |
Camera |
No data |
Camera Flash |
No data |
Connectivity | |
WiFi |
Broken |
Bluetooth |
No data |
GPS |
No data |
NFC |
No data |
Modem | |
Calls |
No data |
SMS |
No data |
Mobile data |
No data |
Miscellaneous | |
FDE |
No data |
USB OTG |
Works |
HDMI/DP |
No data |
Sensors | |
Accelerometer |
No data |
Magnetometer |
No data |
Ambient Light |
No data |
Proximity |
No data |
Hall Effect |
No data |
Haptics |
No data |
Barometer |
No data |
Contributors
Maintainer(s)
Users owning this device
- Annaaurora (Notes: spare phone with pmOS flashed but not booting)
- DragonX256 (Notes: RU variant, collects dust on shelf)
- GamerTygoNL
- Kierownik223 (Notes: Stock software)
- Maciej (Notes: Main device, running LineageOS)
- Rambonette (Notes: Main device, /e/ OS)
- Rjeli
- Secton (Notes: currently android because i couldn't calibrate touchscreen)
Note
This device is quite similar to the Xiaomi Redmi Note 7 (xiaomi-lavender), and many of the issues were solved with steps from that device page, so if you're hacking on the 8T it's a good idea to read the xiaomi-lavender page closely.
How to enter flash mode
Unlocking the bootloader
As with any Xiaomi device, in order to unlock the bootloader you need to sign up for a Mi Account, register your device through the MIUI Settings app (requires a working SIM inserted, but only for a few moments), and wait a week. The official Xiaomi tool only runs on Windows, but XiaoMiTool V2 worked for me on Debian Linux. Be careful, it's a closed source jar!
Before you go further
You are strongly recommended to install TWRP and back up ALL partitions to a safe place! (you can adb pull the images from twrp)
Entering recovery
Hold
+ until you see the recovery screen.Entering fastboot
Hold
+ until you see the fastboot screen.Installation
- Install pmbootstrap.
pmbootstrap -y zap; pmbootstrap init
, choosexiaomi-willow
as your device- firmware is currently needed for tianma touchscreen
- weston is currently the only tested display server
pmbootstrap install
- Enter fastboot, plug USB into computer
pmbootstrap flasher flash_kernel
pmbootstrap flasher flash_rootfs
pmbootstrap flasher flash_vbmeta
- Reboot, sometimes
fastboot reboot
works, otherwise hold down until it reboots to system. - Hopefully weston comes up with
postmarketos-demos
. ssh user@172.16.42.1
You can also use pmbootstrap flasher boot
to boot the kernel/initramfs without flashing.
What's broken
- Restarting the display server will fail (due to panel power issues?)
UART
Necessary: reasonably fine soldering iron tip, steady hand
Highly recommended: microscope, steadier hand
- Disassemble the phone. Here's a decent video.
- I spent way too much time heating up the rubber and trying to use a suction cup. The glue is quite strong, and after heating up the edges to unreasonable temperatures I still couldn't pull the glass off with a suction cup. The key is to heat up the bottom a bit (around 100-150C) and use an extremely thin piece of metal to slide in the bottom and tear the rubber a bit. Then you can keep heating the edges and work your way around the perimeter.
- After removing the glass, remove the ~12ish green screws holding the upper panel in place. One is hidden under a sticker. Pop the panel off with more prying, as gently as you can but some force will be needed.
- This is the end of disassembly, the test points are now exposed.
- Solder as shown in diagram.
- Test connectivity between everything to make sure there's no shorts.
- Connect to your favorite UART adapter. It expects 1.8v, but I used this adapter that only goes down to 3.3v, and it hasn't bricked yet.
screen /dev/ttyUSB0 115200
-
Test point locations
-
Only TX pin soldered
-
Blurry pic of TX and RX soldered (taken pointing from the top of the phone towards the bottom)
Partition Table
xiaomi-willow:~# gdisk -l /dev/mmcblk0
# EXPANDME
Additional Info
Info from the Note 7 port that also applies to the 8T:
- Xiaomi_Redmi_Note_7_(xiaomi-lavender)#Android_Verified_Boot_(vbmeta)
- Xiaomi_Redmi_Note_7_(xiaomi-lavender)#DTBO_partition
- Xiaomi_Redmi_Note_7_(xiaomi-lavender)#Bootloader_cmdline
Kernel config
- Disabled
CONFIG_RNDIS_IPA
because it panics at boot ifCONFIG_USB_CONFIGFS_RNDIS
is set. IPA seems to be an IP offload IC (?) that will route RNDIS straight to the modem with RMNET (?) over BAM (?).
See also
- pmaports!1197 Initial merge request