Droid Incredible custom kernels. The What, Where, and Why.

| July 2, 2010 | 1 Reply



If you are like me and have a freshly Rooted Droid Incredible, you have probably seen or heard about Custom Kernels, more specifically XDA Member ejhart’s “Hydra Kernels”.

I have had a chance to run all of his kernels now, and they are really a matter of preference, but here are my thoughts on them so far.

First you might be wondering, what is a “Kernel”?

The best definition is:

“The kernel is the central component of most computer operating systems; it is a bridge between applications and  the actual data processing done at the hardware level. The kernel’s  responsibilities include managing the system’s resources (the  communication between hardware and software components). Usually as a basic component of an operating system, a kernel can  provide the lowest-level abstraction layer for the resources (especially processors and I/O  devices) that application software must control to perform its  function. It typically makes these facilities available to application processes through inter-process communication mechanisms and system calls.” Taken from Wikapedia .

Still confused?

In laymans terms Custom Kernels offer you options that the stock kernels do not, such as:

Increasing speeds.

Enhanced battery life.

Overclocking your device to make the CPU run faster, and so on….

Now on to the previously mentioned “Hydra Kernels” for the Droid Incredible.

There are two types that I will touch on today, the first is Version 0.2 undervolt kernels.

I have tried the earlier versions of this kernel and have found it to be perfectly stable and also that it adds to my battery life.

This version is Undervolted to allow your device to use less power and therefore add more life to your battery.

It also uses the same stock speeds that the stock HTC kernel does.  I found that after running this for four days and several battery cycles, that I was getting roughly a 10 % increase in my battery life as compared to running the stock HTC kernel!  So if battery life is important to you and you are a heavy user with a rooted Incredible, I would highly recommend Version 0.2 undervolt kernels.

The next version (my favorite) is Version 0.7 overclock.

This is an Overclocked kernel that can reach speeds of up to 1113 mhz as well as being Undervolted.  This is what I use for daily use, because the added speed is just amazing!  The only problem you will get while running this kernel is that you will see a decrease in battery life as you are Overclocking your device, but if you have access to a charger throughout the day, I would highly recommend it as your device will be blazing fast.

Do I use SetCPU with these kernels?

There is some debate as to where or not to use the app “SetCPU” (its in Android market) with these kernels.  Creator of the kernels ejhart says not to use it, and creator of “SetCPU” coolbho3000 says to use it (see debate in this XDA Forums Thread post #274 and on)

Personally I use SetCPU because of the profiles feature that let’s you choose when and how your Overclock runs and at what speeds. You will have to read both arguments and decide for yourself.

To wrap-up, if you are a Droid Incredible owner and have taken the plunge and rooted your phone, you owe it to yourself to go check out some custom kernels and have some fun tweaking your device performance to how you want it.

UPDATE 07/25/10:

New updates on the Hydra Kernels.

Changelog :


v0.3 -More compiler optimizations. Added SoftAP supp PMEM_CACHE_FLUSH code to fix video tearing in CM6 ( support. Added CIFS support.


v0.8 -More compiler optimizations. Added SoftAP support (credit to koush for firmware). Added PMEM_CACHE_FLUSH code to fix video tearing in CM6 (credit to koush for source).Added Loopback device support. Added CIFS support.

I have been running the Overclocked version .8 all day on CM6 Test 7 and its great,  no reboots at all.

ANOTHER UPDATE!  07/30/2010

More new stuff everyone…Hydra Kernels are getting better…go to Hydra page to check em out.

Also if you are like me and have been running Koush’s CM6 froyo ROM, there is a great modified kernel for you!

Originally Posted by rmk40 over at XDA  version 2 of my kernel build is available for cm6 test8, which includes koush’s camera fixes. I take absolutely no credit for any of the code. I’m merely building a kernel with a combination of patches which are known to work. Details: -latest cm6 incredible kernel from koush (taken from git repository) -htc wifi driver with wireless n enabled (this is the key difference) -no overclock or undervolt. -uses koush’s (with hydra’s modifications) kernel installer scripts/tools.

Update 08/12/2010

New Hydra Froyo Kernel .32!


Stock Speed Undervolted Kernels Features:

Kernel version 2.6.32 Stock Speeds Undervolted (100mv at idle, 25mv at 1ghz) Wireless N support Ext4 support TUN support (modular) Kernel compiler optimizations Optimized ondemand governor Loopback device support Wifi Hotspot support (infrastructure AP) CIFS support

Overclocked Kernels Features:

Kernel version 2.6.32 Undervolted (100mv at idle, 25mv at 1ghz) Top speeds ranging from 1.113ghz to 1.15ghz Wireless N support Ext4 support TUN support (modular) Kernel compiler optimizations Optimized ondemand governor Loopback device support Wifi Hotspot support (infrastructure AP) CIFS support 4 kernels configured to run on almost any phone (us determine best for their phone).

Known Bugs for all 08/12/10 Froyo .32 kernels:

IMPORTANT: If you installed v0.4 of the stock speed undervolt or v0.9 of the Overclocked kernels you will need to do an advanced nandroid restore of boot before flashing the newest kernel version in order to fix adb.

Kernels Will not work with CM6. Systempanel not showing correct speeds, monitor graph correct though.


Update 08/20/10:

Here is a new Kernel for those of you running 2.2 Froyo and Sense based ROM’s:

[KERNEL] [] [HAVS] [OC] [UV] KiNgxKernel #3 “Longer Battery Life”


Kernel #3

- Updated for stability

- Introduced the new ‘BFQ’ I/O scheduler!

- Still supporting the ‘CFQ’ I/O scheduler

- Using the ‘BFQ’ I/O scheduler by default

- Benchmark increases

- Undervolted the frequencies that can be

- Pumpin 25 more volts to get the highest speeds stabler

- Updated configurations

- Much much more I won’t even bother explaining

Kernel #2

Kernel #2

-BIG update -

Battery life significantly imrpoved -Fixed HAVS scaling bug -Undervolted even more -Overclockable now up to 1.19Ghz! -Changed I/O scheduler to CFQ -Anticipatory scheduler still supported -Added CPU Governor ‘Conservative’ -Switched default CPU Governor to ‘Conservative’ -Added support for ‘powersaver’ CPU Governor -EXT4 compiled into the kernel now, no longer a module

Kernel #1

- Kernel base

- Flashable update.zip (flash it like a ROM in your recovery)

- HTC Sourced *thank you guys*

- Using Hybrid Adaptive Voltage Scaling (HAVS)

- Long battery life

- Overclockable! Up to 1.113Ghz stable

- Undervolted

- CPU Governor Ondemand supported

- CPU Governor Userspace supported

- CPU Governor Performance supported

- Using CPU Governor Ondemand by default

- Using anticipatory I/O scheduler

- Included tun.ko module

- EXT4 compiled as a module

- Included all the modules you would ever need

- More I will add, it is late and I am tired


Here is a Stock Leak Kernel:

[KERNEL] Stock Unmodified “8/1 Leak” kernel

Thanks rmk40.

This update zip will simply replace the boot partition with the exact  image from the 8/1 leak (  The boot image is the  exact binary provided to us in the leak, I have changed absolutely  nothing.  So, if you want to try the Hydra or King kernels and decide  you want to revert back to the default 8/1 leak kernel, this is a quick  way to do it.

Before anyone asks, why not nandroid restore boot?  These kernels place  modules in /system/lib/modules which need to be reverted as well.  Thus  restoring just boot would be insufficient, one would have to restore  /system as well.


To get some of the mentioned Hydra Kernels go here.

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Category: Android News

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Co-owner and Editor-in-Chief of GizmoNinja.com.

During the day I work in graphic design and also do photography. By night I try to play with programming and code of all different types. I love the opportunity to write for the site and hope to see it grow as time goes on.

  • [...] help some a bit. And I am not a Dev at all, but an advanced user enough to help a bit See here : Droid Incredible custom kernels. The What, Where, and Why. : WJD Designs Cheers! And be sure to give thanks to ejhart and team for the great kernels and work. [...]