Featured image of post PixelExperience 12.1 / 12.1 Plus 20220628-1638 Official Polaris Build

PixelExperience 12.1 / 12.1 Plus 20220628-1638 Official Polaris Build

Linux 4.9.319, latest LLVM Clang 15, lz4 fast decompress loop, mainline exFAT driver, redir_party_num, statusbar height fix, June's security patch, APN updates, and many other 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 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 4.9.319
    • merged CL tag LA.UM.9.8.r1-05000-SDM710.0 into the main kernel and LA.UM.8.3.c25-06200-sdm845.0 into qcacld-3.0
    • built with Prelude Clang based on the latest LLVM Clang 15 source
    • fixed lots of warnings from Clang 15
    • backported lz4’s fast decompress loop from upstream lz4 1.9.3, which offers 10% throughput increase in zram lz4 decompression
    • imported the latest exFAT kernel driver backport from mainline kernel and switched to this driver for exFAT from the old unmaintained sdFAT driver
    • DO NOT use another kernel. Just don’t.
  • Disabled redir_party_num. This should fix the issue of incorrect incoming caller phone number format for some carriers.
  • Dropped an unused DRM build flag
  • Updated deprecated screen power items in power profile
  • Fixed a statusbar height issue after June’s patch

ROM Side Changes

  • June security patch
  • Translation updates
  • Fixed styling issue on DocumentsUI
  • Fixed the issue of the location indicator getting triggered by cellular network activities
  • Fixed a font style discrepancy in the Pixel launcher
  • Reworked several default APN configs
  • Plus edition
    • Fixed the incorrect clock location caused by the network traffic indicator

Known Issues

  • A recent GMS update may start showing un-clickable system update notification. It may also spam your logs with attempts to download system updates designed for actual Pixel phones. It may result in slightly higher battery drain and heat generation especially when you are connected to WiFi. We are aware of this issue. Currently we do not have a perfect solution.

Download | XDA thread

Please report issues to jjpprrrr.

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