Featured image of post PixelExperience 12.1 / 12.1 Plus 20220713-0138 Official Polaris Build

PixelExperience 12.1 / 12.1 Plus 20220713-0138 Official Polaris Build

Linux 4.9.322, massive backports of kernel random generator stack, faster fingerprint unlock, July security patch, system updater storage fix, battery drain and heat build-up fix, and many updated APNs.


  • 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 on PE 12.1. OrangeFox R11.1_1 or newer can boot but is not capable of decrypting the data partition.
    • To switch to other ROMs, format data in PE recovery first, and then install another recovery. You may need to re-flash the required firmware, if the ROM you are going to flash does not include one.
  • You can dirty flash from my previous PE 12 / 12.1 builds. You can dirty flash the Plus edition on top of PE 12 / 12.1 regular 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 12.1 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: Op.12 No.4
    • Linux 4.9.322
    • massive backport of the kernel random number generator stack from upstream common kernel
    • fixed several conflicts caused by the random stack backport
    • disabled qcom’s early random initializer because it is no longer needed
    • use ascii-armor canary to prevent buffer overflow from overwriting canary in fork
    • Wireguard 1.0.20220627 to go with the new random stack
    • fixed several section mismatches in qcom’s regulator drivers
    • fixed an incorrect asoc bound check that potentially causes echo in speaker-mode phone calls
    • DO NOT use another kernel. Just don’t.
  • Moved the fingerprint HAL process out of system-background task group for cpuset
    • this should significantly reduce the fingerprint unlock latency in some cases
  • Corrected the audio HAL service name in power HAL’s restart script

ROM Side Changes

  • July security patch
  • The system updater app will free up its storage after OTA
  • Fixed the issue of Google’s SystemUpdate constantly retrying in the background, draining battery and building heat.
  • Updated lots of APNs

Download | XDA thread

Please report issues to jjpprrrr.

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