yashsingh1/xdaforums huggingface dataset:
[Xoom Android Development] Steady Hawkin:
-Special Instructions-​

This version of Launchpad comes packed with a maximum CPU frequency of 1.7GHz and user adjustable voltages for each frequency. Use these features responsibly!

Do not select "Set on boot"

unless you are confident the settings you chose are stable! Always make backups!

How to use the voltage control:

The stock frequencies and voltages in a kernel are not optimal for everyone. Userspace voltage control lets you either 'undervolt' (to save power) or 'overvolt' (to try and stabilize) any given CPU frequency to meet your needs.

Undervolting-

The easiest way to adjust these voltages is by using the app "Pimp my Cpu", available either from the Market or xda ([APP] 24 June 2011 : Pimp My Cpu 3.0 (OC/UV kernel control tool) - xda-developers). This app will let you to set an undervolt amount for each possible frequency, as well as fill some of the basic overclocking roles of a tool like SetCPU or Droid Overclock.

Note: at this moment, the app "Voltage Control" is not compatible with Launchpad 1.2.0.

Overvolting-

Unfortunately, Pimp my Cpu does not do overvolting, so you need to execute a shell command to set an overvolt amount.

Say for example 1600MHz isn't quite stable, and you want to give it a little help. From either adb shell or Terminal Emulator, execute the following commands:

su

echo "0 -25 0 0 0 0 0 0 0 0 0 0 0" > /sys/devices/system/cpu/cpu0/cpufreq/UV_mV_table

The second line has a series of 13 numbers, mostly zeros. They represent the number of millivolts to subtract from the default voltage of each possible frequency, starting from the higest (1700MHz) to lowest (216MHz). So in the above example, we apply a negative 25 millivolt undervolt ( which transleted to a 25 millivolt overvolt) to the second fastest CPU frequency (1600MHz). Note that the minimum voltage is 770 millivolts and the maximum voltage is 1400 millivolts. If your new voltage exceeds these limits, it will not work.

Here is an example of bumping up 1500, just so you get how its done:

su

echo "0 0 -25 0 0 0 0 0 0 0 0 0 0" > /sys/devices/system/cpu/cpu0/cpufreq/UV_mV_table

In Pimp my CPU, you will see the following as a result of the first command

​
[Xoom Android Development] Steady Hawkin:
-Default Frequency-Voltage Table-​

216MHz @ 770mV

312MHz @ 770mV

456MHz @ 825mV

608MHz @ 900mV

760MHz @ 975mV

816MHz @ 1000mV

912MHz @ 1050mV

1000MHz @ 1100mV

1200MHz @ 1125mV

1400MHz @ 1225mV

1504MHz @ 1250mV

1600MHz @ 1350mV

1700MHz @ 1400mV
[Xoom Android Development] willverduzco:
Glad to see this here! Thank you for bringing this over. I can't wait to try the custom OV/UV.
[Xoom Android Development] Steady Hawkin:
Thanks bro, enjoy:D
[Xoom Android Development] willverduzco:
Would it be possible for you to list the default voltages at each speed so that we know how much we can add or remove before reaching the defined limits?
[Xoom Android Development] Steady Hawkin:
I knew I forgot something, got it added.
[Xoom Android Development] StrifeSoldierVII:
All right! Giving it a go now. Glad to see that undervolting guide! Let's see how it goes! :)
[Xoom Android Development] Lolento:
I have to say this kernel feels much more smooth than tiamat 1.4.4 kernel.

With tiamat, I would have web browser slow down after a long period of use. Not with this one.
[Xoom Android Development] Steady Hawkin:
Thank you for your support. The Tiamat kernel is a Xoom staple and we can't thank BRD and his team enough for all they have done and provided for the Xoom community. Our goal with this kernel is to implement some experimental features and tweaks that we feel can be very useful. Stay on the lookout, good things are coming:D
[Xoom Android Development] maahfu:
i lost sd card support when i flashed launchpad from Tiamat 1.4.4. Any suggestions
[Xoom Android Development] Steady Hawkin:
You lost the /sdcard/external folder? Did you do anything else?
[Xoom Android Development] maahfu:
no the folder is there, but no files appear in it. i flashed the kernel, then light on.zip, and mount audio / video.zip.
[Xoom Android Development] Steady Hawkin:
Flash this in recovery and let me know if it works- http://db.tt/9OEIs5m
[Xoom Android Development] maahfu:
That worked. Was it the mutimedia mount?
[Xoom Android Development] Steady Hawkin:
Yea its an experimental alternative mount for multimedia on the actual sdcard.
[Xoom Android Development] bigrushdog:
Feel free to ask TDR to post or do a pull request for the oc / uv mods or any other mods. I got a lot of stuff on my plate and any extra help would be highly appreciated.
[Xoom Android Development] rschenck:
Good to see that the Xoom devs have a CyanogenMod style sense of cooperation and mutual respect, sharing the code and the credit. It bodes well for great things in the Xoom community when talented devs aren't wasting their time backbiting, trash-talking and trying to get one another banned.

Here's to the continued success of both Launchpad and Tiamat...two great flavors for one fantastic tablet.
[Xoom Android Development] Steady Hawkin:
We will work on getting that done within the next couple days. In the meantime if you need anything please let us know, were happy to help however we can:D
[Xoom Android Development] bigrushdog:
Trust me bro, I'm gonna be needing ALOT of help! Contrary to what some folks think, I'm VERY GLAD to see TDR other guys working on the kernel. I can only juggle so much :rolleyes::D:p
[Xoom Android Development] Steady Hawkin:
Rite on! Well keep doin our thing, in the meantime you know where to find me;)
[Xoom Android Development] Jboxen:
Does the userspace gov act like ondemand or like interactive when scaling? Thanks!
[Xoom Android Development] Steady Hawkin:
I would say its more similar to ondemand, I find I get the best results with interactive.
[Xoom Android Development] Jboxen:
That's what I figured. Hmmm
[Xoom Android Development] theMaDHakkeR:
How did you set the gov? I got pimp my CPU but it said not avail gov found. Any ideas?
[Xoom Android Development] Steady Hawkin:
The gov needs to be set with an oc app such as SetCPU or DroidOverclock.
[Xoom Android Development] theMaDHakkeR:
So I got setcpu and it shows interactive gov now, but pimp my CPU still shows no avail gov. Is that normal? Also pimp my CPU wont let my UV stick for the first 3 steps from 200mhz to 600mhz. Anyone else get this?
[Xoom Android Development] Steady Hawkin:
Yea the governor issue is known. As for undervolting the first three frequencies, I have not tried, but I really don't think its necessary.
[Xoom Android Development] legion21:
any real differences between this and the tiamat kernal?
[Xoom Android Development] RMerlin:
That question also crossed my mind. Having some form of chart comparing available kernels and their respective features would be useful.
[Xoom Android Development] Steady Hawkin:
There are several differences between the two. Mostly small tweaks and experimental additions, the biggest being the custom voltage table.
[Xoom Android Development] legion21:
if I have the launchpad kernel installed is it safe to flash the tiamat kernel on top of that and vice versa, or does flashing a new kernel require a wipe?
[Xoom Android Development] Steady Hawkin:
Yes you can flash between this and tiamat as often as you would like, no manual wipe is required:)
[Xoom Android Development] nswenson:
I've been unable to get the custom voltage table to work. When I reboot, the changes are overwritten and all table changes are lost. I see all zeros in the table. What am I doing wrong? I've made the changes through adb shell and through a terminal emulator. Same result.

Thanks,

Nathan
[Xoom Android Development] Steady Hawkin:
Yea when you reboot the changes are lost. You can simply use terminal or adb to select your desired voltage, no reboot is needed.
[Xoom Android Development] dalvarez7:
Does this kernel keep Superuser permissions? I was on Tiamat kernel but superuser would stop working. Adfree and SetCPU would loose permissions after a couple of minutes. Very frustrating. The Xoom would slow to a crawl and I'd check SetCPU and its back down to 250mhz.
[Xoom Android Development] playya:
I personally have had none of the issues you have mentioned.
[Xoom Android Development] dalvarez7:
I must not be setting SetCPU right. It happened again. I noticed some lag after about 5min and I went back into SetCPU and its running at 256mhz even though I have it set to 1.5 min and max with interactive scaling.
[Xoom Android Development] Steady Hawkin:
Yea I'm not sure, to be honest I have never had that issue either. Maybe try clearing SetCPU from SU permissions, then uninstall and re install it.
[Xoom Android Development] dalvarez7:
Okay so I think I may have figured it out. The problem was when I turned off my Xoom it would drop the mhz down to 216, but then would never go back to 1.5ghz. So I created a profile that told the max and min to be 1.5 when screen goes off. So far so good.
[Xoom Android Development] Steady Hawkin:
Updated, Happy 4th!!!
[Xoom Android Development] bigrushdog:
Wow this kernel is looking great! Good work TDR and Steady. I've been busy with the rom recently and haven't had much time for kernel work. I may just run LP for a few days and give it a test drive :p:D
[Xoom Android Development] yoshitweaky:
can I ask what the two addons do?

I think I am interested in USB WWAN but cant find any additional info on it.

Thanks
[Xoom Android Development] Steady Hawkin:
Thank you very much:D

As a general note, please review the changes made to the voltage table.
[Xoom Android Development] gerald410:
Up and running seems very nice thanks Steady!
[Xoom Android Development] dew.man:
FYI, tried both versions over stock 3.1 on my US WiFi only and it won't boot past the red moto logo. This was just the kernel without either of the add ons.
[Xoom Android Development] gaeng4665:
Same for me...
[Xoom Android Development] Steady Hawkin:
Are both of you coming from Tiamat 1.4.4?
[Xoom Android Development] dew.man:
Stock 3.1 as tiamat caused problems for me at any speed.
[Xoom Android Development] stiffspliff:
hey Steady Hawkin,

just wanted to confirm that like the others before me, it won't go past the moto dualcore screen on stock wifi 3.1 (without the verizon images.. just pure stock wifi 3.1)

flashing on top of the tiamat rom, however works.

hope the information helps you and TDR :)
[Xoom Android Development] keunhuvac:
I have no problem with this kernel (switch from 1.4.5 pre came with tiamat 1.1)!
[Xoom Android Development] gaeng4665:
Hi, yes i am on stock 3.1 with the language pack installed and tiamat 1.4.4 kernel with stock gpu....

I'd very much like to try your kernel, but as said before i get stuck at the motorola logo after flashing your kernel with or without add ons.

What do you suggest?
[Xoom Android Development] w84mike:
Ditto. Been running this all day long now and it is running great.
[Xoom Android Development] Steady Hawkin:
Thanks guys, were working on a fix. In the meantime can someone who is having issues please adb shell into your Xoom when it gets stuck at the dual core screen? (You may need to wait a minute before it works)

Enter:

setprop hc.filesystem.ready 1

and see if it continues booting.

Thanks for your support!!!
[Xoom Android Development] Steady Hawkin:
To the people who are coming from stock 3.1 or Tiamat 1.4.4, if you do not have busybox installed you will get stuck at splash screen. Should have a fix in the next release.
[Xoom Android Development] dew.man:
Ok thanks.

More importantly (at least for me), does your kernel work with flash videos embedded in a web page? For me, only the stock 3.1 kernel does not cause those to crash (especially when rotating between portrait and landscape).

Simple test is to open up Engadget.com in the browser, drill down in to any of the articles that has a video, and try to play it in full screen. All of the kernels I've tried so far (except stock which works fine), cause the video to pause when you rotate the display, and then subsequently FC. Afterwards, I often get other strange behavior in the browser until I reboot. Looks like an Adobe flash problem, but it does work fine with the stock kernel...
[Xoom Android Development] musashiken:
Well I have no such issues with the latest launchpad kernel. Rotating my xoom wifi is fine while the embedded YouTube video is playing. Full screen and non full screen.
[Xoom Android Development] Steady Hawkin:
Yea I have not had an issues either.
[Xoom Android Development] Selbmig:
Been running LP since release no issues whatsoever! Anyone having success with UV? If so how low are you able to go and what app are you using?
[Xoom Android Development] Steady Hawkin:
Good to hear! Yea I run a 25mV undervolt on the N kernel @1400 and its smooth and stable. I have not tried going any lower yet.
[Xoom Android Development] BigBadBuddy:
I tried using ADB to get back into recovery, then re-flashed Tiamat 1.4.4, but I still get stuck at the Dual Core splash screen. Am I missing something? How do I bust it out of this? Any help would be appreciated.

Thanks
[Xoom Android Development] BigBadBuddy:
Nevermind. Figured it out. I had flashed back to Tiamat without flashing the boot image first. Did that and it is back to where I had it.

Thanks
[Xoom Android Development] dew.man:
found a simple way to install 1.2.3 on my stock 3.1: first install 1.2.2, and then 1.2.3

and after playing with a completely stock xoom, I found that the flash video bug exists in the stock firmware a well. ask in ask, 3.1 seems a bit buggy to me.

that said,I am very happy with this kernel so far....

thanks!
[Xoom Android Development] sharptv:
i am running -100mv on all steps(non-N version), fully stable at 1.6ghz. :):D
[Xoom Android Development] Selbmig:
Anyone having trouble getting voltages to stick? Now every time I change they revert back to stock. Re-flashing doesn't fix the problem.
[Xoom Android Development] dew.man:
Had the same problem with PimpMyCpu. Switched to SetCPU - works great!
[Xoom Android Development] Jboxen:
My set CPU voltages table is still backwards with this kernel on tiamat Rom wifi xoom
[Xoom Android Development] Selbmig:
Tried switching apps but my cpu voltages table is still reversed as well.
[Xoom Android Development] Steady Hawkin:
Yea SetCpu has flip flopped the voltage table a few times, most recently rite after we released the kernel:eek: We should have a solution for that soon:D

To anyone who has had an issue with install (freeze @ splash screen): the cause comes from not having busybox installed. It only effects people coming from stock 3.1 or Tiamat 1.4.4. You have two options-

1) Install launchpad 1.2.2 first (this installs busybox automatically)

2) Just install busybox prior to flashing.

As always, thanks for the support:D
[Xoom Android Development] dew.man:
interesting update:

first of all, most of my problems with custom kernels turned out to be a buggy 3.1 stock browser.remedied by switching to dolphin hd.

I've now got this kernel running undervolted like crazy, and rock solid/stable. using setcpu, my xoom is running perfect up to 1600 with undervolt settings of -500 -500 -500 -500 -500 -500 -500 -500-375 -325 -275 -300. that's right, I'm 500 mV under ask the way up to1000 mhz and at 1600 I'm running a lower voltage than stock at 1000. I've stress tested at every frequency, and my xoom is stable!
[Xoom Android Development] Selbmig:
What app are you using to undervolt? Nothing I do seems to stick.
[Xoom Android Development] StrifeSoldierVII:
He is using SetCPU for undervolting, as he did state. I too have all frequencies set to -500mV and it runs smooth as butter. Not one single problem to be reported. I have been running it like this for weeks now. Currently I am running the latest launchpad kernel, and it is running as stable as always while fully undervolted.

I'm going to say to use SetCPU for all of your underclocking, overclocking, and undervolting needs. I'm using it now and it works perfectly. Set the undervolt number, apply, then set at boot. The settings stick, and you sir are now good to go! Enjoy!
[Xoom Android Development] BigBadBuddy:
FYI, I actually tried flashing LP 1.2.3 over Tiamat 1.4.4 with BusyBox installed, but still had the freeze @ the splash screen. I had to reflash the Tiamat kernel and related boot image to get the tablet back. I'm on a wifi only xoom with stock 3.1 and Tiamat 1.4.4. I can try it again, would love to get this kernel working on m tablet.
[Xoom Android Development] Steady Hawkin:
OK so a few things to add.

1) If all goes well we will release updated kernels tomorrow that will address the issue coming from stock 3.1 and Tiamat 1.4.4.

2) For the time being, if you want to undervolt please use Pimp my CPU or Voltage Controll (lite).

Stay tuned, were going to break out the awesome sauce with something sick in the near future!
[Xoom Android Development] StrifeSoldierVII:
Sweet! I like awesome sauce! Looking forward to the updates. I am running your kernel now at max undervoltage, and I must say... good work! Can't wait to see what rolls out next.
[Xoom Android Development] keunhuvac:
I just noticed that: after flashing new 1.2.3 N kernel, my xoom took very long time to boot up (tested with 3 reboots).
[Xoom Android Development] Jboxen:
If you're setting a 500mv undervolt and it doesn't just reboot instaltly, chances are it's not working correctly. That's way too much of an undervolt on the high up numbers to actually be working.
[Xoom Android Development] Steady Hawkin:
That is correct, at this point like I said use one of the two undervolt apps I mentioned earlier. SETCPU voltage controlled is not working at this point.
[Xoom Android Development] StrifeSoldierVII:
Hmm... that makes sense then as to why I could do that without problems. It's not actually working huh? Well, then... lol. Will try the other apps and see whats up with the undervolting.
[Xoom Android Development] Jboxen:
The kernel that comes with the 1.1 tiamat rom which supports undervolting, does work with the setcpu voltage control. Maybe see how they did it as a refference?
[Xoom Android Development] Steady Hawkin:
We know how its done. The issue was the voltage table was reversed again after 1.2.3 was released.
[Xoom Android Development] Jboxen:
I don't really know what that means lol, but I'm a kernel n00b. On a side note, I feel like it would be cool to have a comparison chart between the tiamat kernel and yours. Might get a bunch more people to switch over. Just a suggestion!
[Xoom Android Development] Steady Hawkin:
***Updated***

Please let me know if anyone experiences any issues
[Xoom Android Development] BigBadBuddy:
Just updated successfully. Coming from Tiamat 1.4.4 on stock 3.1 wifi only. So far I'm noticing a little extra pep. I'll report back after some playing.
[Xoom Android Development] Steady Hawkin:
So the update fixed the freezing issue you had?
[Xoom Android Development] BigBadBuddy:
Yeah, installed and rebooted without issue. Very nice kernel!
[Xoom Android Development] gerald410:
running as well no problems to report thx Steady
[Xoom Android Development] Selbmig:
Is the voltage fix included in the update or is that coming later?
[Xoom Android Development] jzun223:
The new update fixed the freezing I had when flashing on stock 3.1. Yesterday (before update) I flashed the kernel and it would freeze at the Moto logo, so I did a nandroid restore I made before I flashed. And today I saw the update so I flashed and everything went smoothly. Thanks!
[Xoom Android Development] Steady Hawkin:
Yes, the next release will include a fix for SetCPU. In the meantime for undervolting use voltage controll (lite) or Pimp my CPU. For overvolting use terminal.
[Xoom Android Development] Dave-Kay:
THX for nice Kernel!

speaking of undervoltage, is the Kernel undervolted himself?

i got my xoom about 10 days ago and the SD-Card arrived on Friday. So i rooted it on the first day and waited for SD-Card to flash it with new ROM.

I flashed Tiamat 1.1 which is pretty nice, but seems to drain the battery more than stock ROM. So i looked for another kernel and found this one. Till now it seems to drain the battery less than with tiamat kernel.

One goal in flashing ROMs for me is to get better battery life. So i would really appreciate the chance to do that. since i bought setCPU, i think i will not buy pimpmyCPU, also.

So, till your new kernel arrives, is there another chance to undervolt it than pimpmycpu?

btw. thanks for the hint to flash 1.2.2 before 1.2.3. it worked without any issue!

and one last question, the mods on FP, i forgot, what the second one was for, but i believe i don't need it. But the first one is (don't know anymore where it was) declared to be a mod for tunneling. what's it needed for? OpenVPN?

Edit: sorry, forgot another thing. in the ARHD-Thread they are using an overclocking daemon instead of CPU-Tools like SetCPU. have you seen it? would it be interesting for the xoom, too?
[Xoom Android Development] ClydeB1:
Steady Hawkin answers your question in the post right before yours - use Voltage Control Lite
[Xoom Android Development] Dave-Kay:
oh dear god! i really didn't see that. i only read pimpmycpu *ashamed*
[Xoom Android Development] ClydeB1:
No worries m8, happens to the best of us.... LOL
[Xoom Android Development] Steady Hawkin:
Tun is for VPN tunneling and USB WWAN is for USB 3G data sticks.
[Xoom Android Development] stiffspliff:
Hey Steady sorry for thelate reply. Both versions of the rev2 gets pass the dual core screen and work well on stock wifi 3.1. Thanks for the quick update!
[Xoom Android Development] Steady Hawkin:
Thanks for testing bro:D
[Xoom Android Development] mulletcutter:
Random reboots at 1700. Tiamat 1.1. Other then that its smooth
[Xoom Android Development] DroidzFX:
So maybe someone can shoot me in the right direction. I have been tiamat for some time now and was going to switch up the kernal to LaunchPad. I can access the sd card while Xoom is on through HD file manager but when I go to CWR it only shows the internal memory when selecting install from zip. Any suggestions for a fix would be great. Thanks
[Xoom Android Development] Noty661:
What version of recovery are you on? Newer recovery updated from ROM Manager did that for me. Had to flash back to 3.2.0.0 (R4c) to get it to work.
[Xoom Android Development] musashiken:
Hi question here, how does the USB WWAN thingy work?

I can just plug in a USB 3G Dongle and it will work or am I missing something?

Some carrier dongles require additional software to work on the PC, at least that's what I heard.

EDIT: Ok, after some searching I managed to find instructions for running a script to enable USB tethering from my Nexus One to my Xoom and it works, although the script gave some timing error. I believe this came from bigrushdog.

But the script doesn't work for the USB 3G sim dongle I have. It's supposedly an unlocked 3G dongle that I borrowed from a friend.

In case anyone is interested in using USB tethering from a 3G phone to the Xoom, instructions below.
[Xoom Android Development] DroidzFX:
Yeah 3.0.2.5 did it. Funny thing I'm pretty sure I tried that. It always works after someone tells you to do it.
[Xoom Android Development] playya:
will there be an updated version of this nice kernel for android 3.2
[Xoom Android Development] Steady Hawkin:
Yes there definitely will be, I'm currently running a test version. Shouldn't be to far out:D
[Xoom Android Development] playya:
Thanks man really got some good battery life and CPU scaling from 1.2.3 was quite impressed..
[Xoom Android Development] Dave-Kay:
as i think it's pretty clear, the 3.2verion has a high priority, will there be a 1.2.4 for 3.1, too, maybe later?

atm there's no 3.2 for 3g and it would be very nice to improve 3.1.
[Xoom Android Development] Marshall1975:
Hello

I have a slight problem with this kernal on my UK 3g xoom running Aus 3.1 image. All works well except if I try to go into storage under settings it forces close. Im wondering because the Aus 3.1 has SD support built in maybe thats causing the problem with this kernal as it supports SD also.

Cheers
[Xoom Android Development] Steady Hawkin:
Yes, the update will cover both 3.1 & 3.2. I'm on 3G as well;)