[Miscellaneous Android Development] lindsaytheflint:
Presenting the Stone Kernel for ASUS Padfone 2 (A68), a custom kernel designed to get a little more out of the Padfone 2.

DISCLAIMER: As per all custom kernel disclaimers, while I do test this kernel on my own device, I'm not responsible for you voiding your warranty, or any damage/bricking/weirdness that may occur to your Padfone. If you're not comfortable with this, do not proceed.

v0.9

Main features:

Based on ASUS source code v10.4.16.8, compatible with Android 4.1.1 stock PadFone2 firmwares

init.d support (init.rc busybox runparts)

USB OTG Host in phone mode

UI rendered with GPU instead of CPU, making it very snappy

Lowest CPU frequency set to 162mhz

CPU frequency locked to 162mhz-1512mhz during boot

Undervolted to save power & reduce heat

Undervolt interface (compatible with System Tuner, Kernel Tuner, etc)

Additional CPU Governors: Wheatley, InteractiveX v2, MSM_DCVS

Set InteractiveX v2 CPU Governor to default instead of Performance, to lower battery consumption, maintain snappy performance, and improve CPU freq config

GPU normal freq set to 200mhz to lower battery usage (will still scale upto 266/400/533mhz when busy)

Simple IO Scheduler (SIO) added, and set as default

Increased min/max read-ahead values from 16/128 to 32/2048

USB FastCharge upto 1400mA (enable using Kernel Tuner, sysfs, etc)

Lower minimum brightness to save power

Lower voltage for display (~13% lower voltage) to save power

NTFS USB drives need USB OTG Helper software or similar - working on fixing the NTFS module

Increased file cache ratio to improve storage performance

Standard edition: CPU max 1.51ghz, GPU max 400mhz

Overclock edition: CPU max 1.72ghz, GPU max 533mhz, low voltages

Powersaver edition: CPU max 1.35ghz, GPU max 266mhz, low voltages

Minor tweaks:

Replace Wifi modules with AOSP versions (needed due to the way the stock modules were compiled by ASUS)

Disabled swap

Disabled "Compile the kernel with debug info"

Disabled Debug memory initialisation

Disabled Magic SysRq key

NTFS in kernel (instead of module)

FAT support

Improved CPU multi-core frequency limiting

GitHub: https://github.com/lindsaytheflint/stone

Download:

Stock kernel 10.4.12.24: https://docs.google.com/file/d/0ByOiY1XD_cLvNVFwVi1Yc3lmS2M/edit?usp=sharing

Stock kernel 10.4.15.1: https://docs.google.com/file/d/0ByOiY1XD_cLvVU5KWkJqZzVrU00/edit?usp=sharing

Stock kernel 10.4.16.8: https://docs.google.com/file/d/0ByOiY1XD_cLvaGR2X19RS2hOa28/edit?usp=sharing

Stone kernel v0.1 "Dual": https://docs.google.com/file/d/0ByOiY1XD_cLva0Q3el9VbU1vd1k/edit?usp=sharing

Stone kernel v0.1 "Quad": https://docs.google.com/file/d/0ByOiY1XD_cLvdk9EcTAtdXdDRGM/edit?usp=sharing

Stone kernel v0.2 "Standard voltage": https://docs.google.com/file/d/0ByOiY1XD_cLvUFpSenoyXzFYRVk/edit?usp=sharing

Stone kernel v0.2 "Low voltage": https://docs.google.com/file/d/0ByOiY1XD_cLvclVXdEs4Qm1sb0U/edit?usp=sharing

Stone kernel v0.3 "OC": https://docs.google.com/file/d/0ByOiY1XD_cLvd28ybVB2MHhXTXc/edit?usp=sharing

Stone kernel v0.3 "STD": https://docs.google.com/file/d/0ByOiY1XD_cLvUnI4Z01YYzZBY1k/edit?usp=sharing

Stone kernel v0.4 "OC": https://docs.google.com/file/d/0ByOiY1XD_cLvd1lOQmI4c2duaGc/edit?usp=sharing

Stone kernel v0.4 "STD": https://docs.google.com/file/d/0ByOiY1XD_cLvM2QxdXVFMGcxRm8/edit?usp=sharing

Stone kernel v0.6 "OC": https://docs.google.com/file/d/0ByOiY1XD_cLvSm9XQVBqTWtBUEU/edit?usp=sharing

Stone kernel v0.6 "STD": https://docs.google.com/file/d/0ByOiY1XD_cLvN3otdjM3elNHYUk/edit?usp=sharing

Stone kernel v0.7 "OC": https://docs.google.com/file/d/0ByOiY1XD_cLvbTBralZ4aVZFOVk/edit?usp=sharing

Stone kernel v0.7 "STD": https://docs.google.com/file/d/0ByOiY1XD_cLvTGc2YWJFWFYxWGM/edit?usp=sharing

Stone kernel v0.8 "STD": https://docs.google.com/file/d/0ByOiY1XD_cLvNGxheldqTThNT2c/edit?usp=sharing

Stone kernel v0.8 "OC": https://docs.google.com/file/d/0ByOiY1XD_cLvOWw4cFBGb0xyUEk/edit?usp=sharing

Stone kernel v0.8 "PS": https://docs.google.com/file/d/0ByOiY1XD_cLvemtzSTlMZEpGcU0/edit?usp=sharing

Stone kernel v0.9 "STD": https://docs.google.com/file/d/0ByOiY1XD_cLvbUxWRHVPd1cyX2s/edit?usp=sharing

Stone kernel v0.9 "OC": https://docs.google.com/file/d/0ByOiY1XD_cLvd3FQOXJnbVZVbFE/edit?usp=sharing

Stone kernel v0.9 "PS": https://docs.google.com/file/d/0ByOiY1XD_cLvbm5qNFdHZWcwYjA/edit?usp=sharing

Installation:

1. Copy StoneK_A68_v0.9_OC.zip or StoneK_A68_v0.9_STD.zip to /sdcard/ via USB.

2. Copy StockKern_A68_10.4.16.8.zip to /sdcard/ via USB, in case you have trouble booting, and need to uninstall.

3. Boot into TWRP or CWM Recovery.

4. Perform backup of at least your "Boot" partition.

5. Install zip from step 1.

6. Reboot.

Uninstallation:

1. Copy StockKern_A68_10.4.16.8.zip to /sdcard/ via USB.

2. Boot into TWRP or CWM Recovery.

3. Install zip from step 1.

4. Reboot.