[KERNEL] [GPL] Quickie - Flashable Overclock Kernel - "Screamer"

1,094 posts
Thanks Meter: 167
By Geniusdog254, Retired Recognized Developer on 11th January 2011, 06:06 AM
Post Reply Subscribe to Thread Email Thread
Title says a helluva lot ;)


  • All steps undervolted about 25%. Should be stable still
  • The table is currently 300, 600, 950mhz until I can make it scale more than 3 steps.
  • The voltage for 950Mhz is less than at stock for 800Mhz, so you should see better battery life even though we're overclocked.
  • Display flicker fixed (or at least toned down, it can't be completely eliminated with the LED backlighting)
  • Scheduler tweaks backported from later kernel versions
  • Some governor tweaks of my own for responsiveness

To install this, just flash the zip in ClockworkMod. This shouldn't harm your device, but I make no promises. I trust it enough to run it on my device, if that means anything to y'all. I also attached a zip to flash back to the stock kernel (..but why would you break my heart by doing so..? ;P).

Next Up:
  • I REALLY want to get 1Ghz+ working, and my code is sound (I'm sure of that) but it won't boot on my device. I think I just need to find the right voltage, or I could have a bad die for OC'ing. This is the first thing I will work on.
  • Maybe the interactive CPU governor
  • Look into the 2-point touch limitation

Source is available on my GitHub at

I will not flat out ask for donations, however I do appreciate them. So if you're feeling generous or appreciate my work then it would help me out a lot if you could donate. I have my game Reflex-A-Tron on the Market for $1 if you'd like to donate like that, or there is a link under my name on the left side to donate, and one in my signature. The one on the left and in my signature is to donate via PayPal. Any amount is appreciated, but please don't feel obligated.

You can contact me here via PM, on Twitter @geniusdog254, or email me at Email or Twitter is the preferred method, because I really despise the XDA PM system.

If this breaks your Nook, kills your family/pets, or starts global thermonuclear war, do not blame me. You have been warned. If you break your device and blame me, I will point at you and laugh.
Attached Files
File Type: zip - [Click for QR Code] (2.09 MB, 2315 views)
File Type: zip - [Click for QR Code] (2.19 MB, 1537 views)
File Type: zip - [Click for QR Code] (2.19 MB, 4523 views)
File Type: zip - [Click for QR Code] (2.19 MB, 2295 views)
Last edited by Geniusdog254; 20th January 2011 at 05:53 PM.
The Following 33 Users Say Thank You to Geniusdog254 For This Useful Post: [ View ]
11th January 2011, 06:07 AM |#2  
Geniusdog254's Avatar
OP Retired Recognized Developer
Flag St. Louis
Thanks Meter: 167
Donate to Me

1-11-11 - Screamer:
  • Overclock to 950Mhz. Still chokes at 1Ghz, which tells me it's probably my device. 950 is stable.
  • Temp sensor drivers. Thanks to the Nookie FroYo guys!
  • Updated to
  • Scheduling tweaks from 2.6.31.
  • Code idle time from 2.6.34.
  • Scaling fixed. Now scales properly between all 3 CPU levels. Adding more than 3 makes it choke for some reason. I'll look into it.
  • Test version set at 1Ghz added. Just because it doesn't work for me doesn't mean it won't work for you. Don't get your hopes up though, I've tried making it work every way from Sunday

  • Screen WILL be unresponsive immediately after a boot. Just lock the device for several seconds, unlock it, and all will be fine until another reboot. I blame B&N, it happens with all custom kernels.
  • Yes, I know there are more versions of this kernel than there are Windows Vista. The middle one is the recommended one. If your Nook can't run at 950Mhz (crashing often, or just won't boot) try the one with the 900mhz tag. If you wanna try and push it higher, try the 1Ghz one. Be warned: very little success is reported with the 1Ghz kernel. The top level of these chips seems to be right around ~925-975Mhz. Very few devices will be able to hit 1Ghz.
  • You should probably wipe your cache partition after flashing this. You won't lose anything, and many people are reporting that it makes things more stable at the higher freqs for them.

MD5 Sums:
  • 78ccf8ab0cd35b988cc9a81bd8bbc310
  • 7076a88cae2229910478e698c0e19435
  • 22e8c2cc21e42cca1d18377a92b49540
  • 40362515da86cb4baea37b0bc6358feb
Last edited by Geniusdog254; 20th January 2011 at 05:52 PM.
The Following 5 Users Say Thank You to Geniusdog254 For This Useful Post: [ View ]
11th January 2011, 06:22 AM |#3  
Senior Member
Miramar, FL
Thanks Meter: 11
Wow thanks so much for this. Gotta try it out!
11th January 2011, 06:35 AM |#4  
ahfunaki's Avatar
Senior Member
Thanks Meter: 9
wow very nice! going to have to give this a shot!
11th January 2011, 06:47 AM |#5  
runhopskipjump's Avatar
Senior Member
Thanks Meter: 45
Awesome! But is it compatible with nookie froyo (2.2) or the stock BN (2.1)?

Update: It boots Nookie Froyo but powers off immediately after booting. I am looking forward to the release of the 2.6.32 version of your work. Keep up the good work!

Sent from Nook Color (Nookie Froyo microSd optional)
11th January 2011, 06:51 AM |#6  
Geniusdog254's Avatar
OP Retired Recognized Developer
Flag St. Louis
Thanks Meter: 167
Donate to Me
Originally Posted by runhopskipjump

Awesome! But is it compatible with nookie froyo (2.2) or the stock BN (2.1)?

Sent from Nook Color (Nookie Froyo on emmc)

Just stock 2.1.

With the Nookie FroYo, it wouldn't flash the kernel to the SD for boot, plus (at least on th Epic) a 2.6.29 kernel won't boot on FroYo, it needs 2.6.32 or higher
The Following User Says Thank You to Geniusdog254 For This Useful Post: [ View ]
11th January 2011, 08:13 AM |#7  
Junior Member
Thanks Meter: 0
Glad to have you part of the nook color family. You did awesome work on the Epic4G.

Looking forward to more great stuff from you.


Sent from my LogicPD Zoom2 using Tapatalk
11th January 2011, 09:32 AM |#8  
Senior Member
Flag Pasadena, CA
Thanks Meter: 20
Loss of touch sensitivity
I loaded up the new kernel via Clockwork and all went smoothly with the install. I noticed immediately that my touch sensitivity has decreased. I now have to press and hold just about as long as you would press and hold to bring up a context menu or something. If I don't do that, my touch is ignored and not registered.

Interestingly enough, when I type an email on the keyboard, it recognizes my typing very quickly. No apparent loss of sensitivity when I'm using the keyboard. I wonder why and how that is???

I guess I need to recalibrate the screen again to regain sensitivity.

I did notice that Castle Crashers frame-rate has improved a good bit with the overclock. It's a noticeable and welcome difference.

Angry birds was a bit annoying to play with the loss of screen sensitivity.

Edit: I alleviated the loss of touch sensitivity by installing the LCDDensity app from the Android Marketplace and selecting a density of 200.
Last edited by deitiphobia; 11th January 2011 at 09:41 AM.
The Following 2 Users Say Thank You to deitiphobia For This Useful Post: [ View ]
11th January 2011, 12:05 PM |#9  
Thanks Meter: 4
Tried to install via clockwork and I keep getting errors unable to install. an I missing something?

sent from my nookcolor using the xda app

Got it working with clockwork update... thanks!
Last edited by nrune; 12th January 2011 at 02:22 AM. Reason: update
11th January 2011, 12:28 PM |#10  
Junior Member
Thanks Meter: 4
Thumbs up
Flashed. Am loving it, seems much snappier, and the keyboard response at 900mhzz is much improved. Keep up the good work!
11th January 2011, 01:09 PM |#11  
Thanks Meter: 132
NC overcklock

Last month I made some tests with overcloking /undervolting. I was able to push the NC at 1.15GHz, with a little voltage tweaking. 1Ghz was achieved without voltage tuning. The smartreflex technology adjusts automaticaly the OPP voltages to minimize the power consumption. Maybe the L3 speed can be increased to 200 Mhz by setting DPLL at 400MHz (in u-boot).

Occip (working for 2.6.32 NC kernel)

Read More
Post Reply Subscribe to Thread
Previous Thread Next Thread
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes