Development [Kernel][23.12.2021][Android 11] Kirisakura 1.0.1 for Sony Xperia 1 III aka "Sagami"

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Senior Member
Mar 29, 2020
check the original post about the A12 kernel.

Unfortunately I can´t do anything about it, as there´s no source for A12 and it´s impossible to know what to change for the charge service.
Plug it to a pc (you´ll see charging), disconnect it and plug into your charger. That works for me with the sony charger that was in the box. After a while it will detect a PD type charger and switch to fast charging.
**** man this drove me insane tbh i thought my phone was broken. well hope you get it working soon...


Recognized Developer / Recognized Contributor
Jan 2, 2011
Will there be an update for Android 12??
read back two pages in this thread. I shared builds for A12.
As there´s no source code published for A12 yet from Sony I suggested you read my posts thoroughly so you´re not getting any surprises. (usb/charger detection can be wonky)

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    Kirisakura-Kernel for the Sony Xperia 1 III

    Hello everyone,

    To keep it short: Here is Kirisakura - Kernel for the Sony Xperia 1 III aka Sagami. Sagami is the internal codename for this years development platform of Sony Mark III devices. Please note this kernel is made to run only on Xperia 1 III.
    I would appreciate if everybody that flashes the kernel, reads at least once through this opening post and the following ones.

    Kirisakura - Kernel is designed to bring a handful of beneficial features to the device, while ensuring excellent performance and smoothness to get you safely through the day!
    If you expect a custom kernel to magically improve your devices battery life manifold and this is your only priority then this might not be the right place for you.
    However the kernel is built to keep battery life close to the same as you would experience the on stock kernel while being tuned to perform better in various UI related benchmarks. The same benches are used by google to verify and ensure UI smoothness on the Pixel devices.
    There´s also a cpu-battery saver mode that cuts back the CPU max- freqs, but without the disadvantages like delayed notifications from built into the system user-space power-saving modes.
    If that got your curious, I welcome you to continue reading if you´re still interested!

    The kernel includes a lot of improvements and contributions from other developers as well. Without this kernel would not exist.
    A big part of improvements originate from @arter97´s, @kdrag0n´s and @Sultanxda´s work. Many others contributed in some way or another to this kernel.
    A big thanks to all of them at this place!

    Now lets continue with a list of features in the next paragraph!

    Main Features:
    - Based on latest kernel sources from Sony for Android 11 and intended to be used on the latest Stock-Firmware (currently 61.0.A.23.20 )
    - compiled with Clang 13.0.1 and built with -O3 speed optimizations
    - CPU-Battery saver to be able to restrict max cpufreqs on the fly, without enabling powersaving modes that might cause missed notifications (more info here)
    - include important fixes/improvements from kernel/common
    - reduce power consumption during deep sleep
    - remove logging while device is suspended
    - disable various debugging mechanisms for drivers which are not needed on a perf build (e.g. binder)
    - disable unnecessary CPU errata for our specific SoC
    - implement LRNG (thanks @arter97, see arter kernel OP for more info )
    - Flashing the kernel will keep root!
    - Flashable via EXKM, FKM or TWRP (if available) on a rooted system!

    CPU related features:
    - Power saving workingqueues enabled by default (toggleable in EXKM)
    - Change various drivers (WLAN, MM, audio, charger, power, thermal, glink etc) to use power efficient workingqueues. This compliments EAS in general
    - improvements to cpufreq
    - vdso32 patches as found on Google Pixel devices (brief documentation here) (CAF 5.4 default, keep for documentation)
    - disable debugging during sleep states as per qcom recommendation
    - remove RTB logging to reduce overhead
    - disable edac (following google on the pixel kernels)
    - disable jtagv8 debugging as recommended by qcom for perf builds to avoid potential power, performance and memory penalty
    - disable s2idle in favor of deep idle state -> improves deep sleep drain (google initially used 2idle for improved suspend/resume latency on pixel 3 and pixel 4, but disabled it on pixel 5. qcom followed suit for sd 888, but apparently didn´t see google reverting it on pixel 5. Other OEMs such as Xiaomi or OnePlus already disabled s2idle on their SD888 devices in favor of deep- read more about s2idle vs deep here)

    GPU related features:
    - gpu/kgsl improvements from pixel 4/pixel 5 kernel
    - add low_prio_worker thread for gpu driver (Improves performance when tearing down processes (eg, via LMK) and not blocking currently running UI from submitting work to the GPU
    - remove POPP functionality from GPU driver to avoid constant fight about downscaling with msm-adreno-tz
    - increase gpu worker thread priority
    - don´t wait for fenced GMU writes

    File System related features:
    - upstream BFQ-MQ to latest state in linux-mainline and default to 128KB readahead
    - improve memory allocations in kernfs
    - ufs improvements from pixel 4/ pixel 5 kernel
    - improve GC as to not interfere while user interaction is happening and prevent possible jitter or latency spikes
    - improvements to deep sleep power consumption (ufs driver, auto hibernate)

    Network related features:
    - Wireguard Support (Details)
    - advanced TCP algorithms enabled
    - use bbr as default TCP congestion algorithm (fasted algo according to this excellent research from @kdrag0n found here )
    - remove unnecessary wakelock from WLAN driver to reduce thousands of very short wakeups during a 7 hour deep sleep period
    - improved bluetooth performance (¹, ²)
    - Enable support for TTL spoofing

    Memory related features:
    - Speculative Page Faults left enabled (1. 2) (CAF 5.4 default, keep for documentation)
    - improve memory allocations in various subsystems, video encode/decode, kernfs, cgroup
    - mm: Micro-optimize PID map reads for arm64 (improves game performance, especially unity engine based games such as genshin impact)

    Security related features:
    - Control-Flow-Integration (CFI) and Link-Time-Optimization (LTO) (CAF 5.4 default, keep for documentation)
    - Use ThinLTO which was first used in the Pixel 4 XL Android R-Kernel instead of full LTO (CAF 5.4 default, keep for documentation)
    - Shadow Call Stack (SCS) Security-Feature ( 5.4 default, keep for documentation)
    - enable init_on_alloc for even more security, more information can be found in the commit message (CAF 5.4 default, keep for documentation)

    Other features:
    - disable logging and debugging to make the kernel more lightweight in various places (includes binder, mm, vma, gpu, ipa etc)
    - fix several coding issues detected by newer Clang-Toolchains
    - enlarge dmesg size to ease debugging

    Flashing Guide, Download and Changelog

    - unlocked Bootloader
    - USB-Debugging in developer options enabled
    - latest adb and fastboot binaries
    - working adb and fastboot environment
    - magisk root
    - a backup of stock boot.img or your magisk patched boot.img in case you want to go back to stock.

    How to flash the Kernel:
    1. Download the latest and make sure you have properly updated to the latest matching Firmware (check the feature list for the current firmware the source is based on). When there´s an OTA update for the Sony Xperia 1 III it takes Sony a while to release the source code for the new OS and me a while to build a new kernel. If you don´t want to face any issues, wait until I either release an updated kernel or give green light because there were no kernel changes.
    If you want to be sure there are no issues, always make sure to run the firmware the kernel is built for!
    If you feel adventurous and try in advance, make sure you have a backup ready!

    2. Flash the via latest TWRP (if available), EXKM or FKM app and do a full reboot.

    3. Reboot and profit.

    Download is located always in this folder:

    Important: Read after Download
    Please take a look at the second post after flashing the kernel!

    Android 11

    1.0.0 Initial Release

    Donations are not mandatory but very welcome if you want to support development or just buy me a coffee/tea :)
    If you like my work:

    Sony for the development device, giving me the opportunity to create this project!
    @osm0sis for all his work, including the ak3 installer!
    @tbalden for being the best HTC, Pixel, OnePlus and now Asus wingman!
    @LeeDroid and @mwilky for their awesome roms and work I used on multiple devices!
    @Captain_Throwback for all the mentoring and guidance!
    @Eliminater74 for bringing me into the game and the Inspiration
    @nathanchance for his upstream guidance and assistance
    @RenderBroken for helping me out
    @flar2 for all his work
    @joshuous for all the help he provided to me in the past!
    @arter97 for giving me advice
    @kdrag0n for his help and advices!
    @topjohnwu for magisk!

    Source Code:
    Android 12 Kernel

    Hey everyone :)

    So I have to be honest with this post. It´s extremely frustrating for me that there´s no source code pushed yet for the Android 12 firmware. The first Android 12 Firmware (.149) was released at the beginning of January, with another update to .211 a while ago.

    No source whatsoever for A12 at this point. It´s frustrating after 2 months.
    I understand not every OEM has the ecosystem and means of google to push the source hours after the OTA is live, but 2 months is a really long time. It´s still a long time considering the kernel is based on a completely new qcom base and probably needs to be "re-edited" (deleting comments, wip progress marks, etc) before uploading the source archive in contrast to the more "simple" A11 updates, which is probably just a drag and drop operation and happened way more quickly.
    Given Sony more or less advertises their open source ambitions in various places it´s disappointing from my perspective.

    The A11 kernel source isn´t compatible with A12 and doesn´t boot.

    However the more I got frustrated over time I more or less hacked together a kernel for A12, which is working as best as its going to get without a matching source.
    That kernel is based on latest linux-stable and latest caf-upstream, with loads of other optimizations that were not in the A11 kernel, but were contained in my other kernels for 5.4 devices.

    The only real issue on that kernel is that usb port detection is wonky. It takes a while to detect a pc and for the usb file transfer dialog to pop up.
    My old Pixel charging brick works fine ( it takes a little while to get detected sometimes), while the stock charger only works if I connect the phone to my PC usb and directly afterwards to the stock sony charging brick.
    Otherwise there are no real issues for me.

    Feel free to test, but I probably won´t be able to fix any problems until we have a source code for the A12 kernel.
    Alright here´s a that just force loads all drivers built as kernel modules that come bundled with the firmware. This means instead of building the full kernel from source, we just build the core and load all drivers from the stock firmware compilation from sony. This includes, fingerprint, camera, touchscreen etc and also the sony driver that´s responsible for battery care/smart charging. I think this should fix the smart charging issue for now.

    However I don´t like to do this as force loading modules can cause issues, if the kernel gets to far from the stock base as already happened on the initial release.
    I already needed to revert certain changes done to the full source built kernel, as force loading modules on the previous 1.0.1 release would just crash the device during startup.
    For now it´s fine, but the kernel I plan to do once A12 drops won´t be able to resort to this approach as it will contain a lot more changes.

    I hope I can get this driver somewhere so I can proceed to go forward as planned.

    Source is pushed to a different branch.

    Enjoy the holidays and have a nice Christmas time if you celebrate it. :)

    Is root preserved when flashing this kernel?
    Answer: Yes, the will detect root and keep it.

    Question: Safetynet does not pass on my phone since I unlocked the phone, why is this so?
    Answer: Google introduced hardware backed attestation recently. Unfortunately the old kernel tricks to still get safetynet passing won´t work. Instead you will have to rely on some magisk modules. Short guide in post #4 below.

    Question: How do I return back to stock or another kernel.
    Answer: Extract boot.img from the matching firmware you are on (you can do so by using this tool or similar ones found on XDA and when googling around) and flash them via fastboot. If you want to keep root flash back the magisk_patched_boot.img. Or dirty flash your rom and re-root.

    Question: Why is having Magisk installed mandatory for this kernel?
    Answer: The kernel uses a ramdisk overlay to apply some settings after boot. If you are not rooted these settings will not get applied and you miss some of the optimizations.

    Question: How to report bugs properly?
    Answer: Have a look at post #3 in the linked thread. The linked guide is a pretty good starting point.
    Before reporting any bug make sure you´re running on a stock configuration. That´s means you´re not using any mods, tweaks in kernel managers or other root tweaks , magisk modules, scripts or other modifications that alter various functions like sound mods, data traffic, sleeping behaviour, scheduler, magical battery tweaks etc.
    Try to describe the issue as detailed as possible! Give your exact setup, like rom, magisk version, kernel version.
    Is the issue reproducible? Does it happen frequently?
    Provide logs, otherwise debugging is a lot harder. If you can already reproduce the issue and provide logs it greatly limits the amount of time I have to spent until I figure out how to reproduce it.

    If the device force reboots/randomly reboots (that means you see the bootloader unlocked screen!) provide a .zip of /asdf.
    Easiest way is immediately after booting up, with a root explorer navigate to /asdf. Copy the contents to your internal storage, zip it up and send it to me.

    If the issue happens while the device is running provide a dmesg plus a logcat that you take while/shortly after the issue happens. This will log what´s running in the current session. Try to be as detailed as possible what´s happening when the issue appears. It will also help me in reading the log!
    this one is the last one