Featured image of post PixelExperience 12 20211223-0300 Official Polaris Build

PixelExperience 12 20211223-0300 Official Polaris Build

Linux 4.9.294, QTI BT stack, cpu frequency increase for INTERACTION hint, haptic feedback for notification pull-down, audio config update, December security patch, and many fixes.


  • Formatting data with PE recovery is REQUIRED for clean flash
    • DO NOT use any other recovery
    • The firmware is included with a different keymaster.img from perseus. DO NOT flash your own firmware.
    • Keymaster is bumped to 4.0 for encryption, and cust partition is mounted as /metadata. You WILL NOT be able to boot TWRP/OrangeFox on PE12.
    • If you need to switch to another ROM, format data with PE recovery first, and then install TWRP/OrangeFox in fastboot.
  • You can dirty flash from my previous PE 12 builds.
  • You cannot upgrade from android 11 directly. Formatting data is required.

PE recovery flash guide

  • Download PE recovery from the official PE website
  • Boot your phone into fastboot mode. You can either
    • hold power + volume down button
    • or adb reboot bootloader
    • or use the Reboot to bootloader option in TWRP/OrangeFox
  • Connect your phone to a computer
  • Run fastboot flash recovery pe_recovery_file_name.img in your cmd/powershell/terminal
  • Hold power + volume up to boot into recovery

PE 12 flash guide

  • Boot into PE recovery
  • Select Factory reset" --> "Format data/factory reset. You phone should say that /data, /cache, and /metadata have been formatted.
  • Go back to main menu and select “Apply update” –> “Apply from ADB”
  • Connect your phone to a computer
  • Run adb sideload in your cmd/powershell/terminal and wait until it finishes
  • Reboot to system

Device Specific Changes:

  • Etude kernel:
    • Linux 4.9.294 and CAF tag LA.UM.10.3.r1-00500-sdm845.0
    • DO NOT use another kernel. Just don’t.
  • Switched to QTI BT stack
  • Raised the minimal CPU frequencies for INTERACTION hint
    • reduce jank when scrolling through lots of images and videos
  • Enabled haptic feedback when pulling down notification panel from the status bar
  • Dropped unused entries from mixer paths and audio platform info config
  • Adapted XiaomiParts to new style

ROM side updates:

  • December security patch
  • Fixed an issue where GMS downloads system updates for Pixel phones in the background and potentially drains data
  • Enabled the option of Adaptive Sound
  • Brought back the system updater
  • Misc fixes and improvements

Known Issues

  • Rounded corners are broken. It does not seem to be an issue on the device side, as debug info reports correct values

Download | XDA thread

Please report issues to jjpprrrr.

Licensed under CC BY-NC-SA 4.0
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