Database Users

Custom kernel queries

Hi there, just want to begin by saying how amazing this community is. I'm new to whole Android scene (just came over from iOS) but what a welcome it has been! I'm blown away by the amount of ways you can customize your Nexus 7, really puts the iPad to shame
So I've rooted my Nexus 7 and am now hoping to install a custom kernel...however I have quite a few questions pertaining to this procedure.
1) How do I install a custom kernel (ie Trinity)?
2) I'm looking to improve battery life without compromising performance, what kernel would you recommend for this?
3) Can I still get OTA if I have a custom kernel?
4) Can I revert back to stock kernel and if so, how do I do this?
Sorry to come across as a newb, I saw a lot of helpful threads on custom ROMs however I found the stuff on kernels a bit daunting...Hopefully this thread will be helpful for others as well
Thanks again everyone.
Sent from my Nexus 7 using xda app-developers app

1. just flash it in recovery, dont wipe a thing.
2. trinity
3. kernels dont have anything to do with ota. if its still enabled in your rom then yes.
4. either fastboot flash a stock boot.img or just reflash your rom without wiping anything.
5.

Worth noting that when a new rom is installed it installs its own kernel so you'll have to reflash your kernel.
I also recommend faux for good battery life. Both that and Trinity are good.
Sent from my LG-P999 using xda app-developers app

[Q] Would rooting/installing custom rom improve Nexus7?

I recently rooted and installed a custom rom on my phone and noticed huge improvements. Noticed my nexus was lagging on things that I would think shouldn't be that taxing on the device. Thought the OTA update to 4.2 would help but it didn't. Would rooting it get rid of that lag or is it just a nexus thing?

sourshin said:
I recently rooted and installed a custom rom on my phone and noticed huge improvements. Noticed my nexus was lagging on things that I would think shouldn't be that taxing on the device. Thought the OTA update to 4.2 would help but it didn't. Would rooting it get rid of that lag or is it just a nexus thing?
Click to expand...
Click to collapse
Personally because of the big change over from 4.1 to 4.2 i decided to go back to stock for awhile and wait for the bugs to be sorted.
Re-unlocked and rooted, flashed faux kernel and is the best experience i have had to date. Meaning the least lag. Stock and custom kernel. Just unlock - root and then flash kernel. :good:
Not a detailed description but if you need further advice just say so......Just means unlocking installing CWM and SU...Then flash kernel of choice. recommend faux..

I've tried out a rooted nexus 7 and to be honest didn't see a huge improvement so I've decided to wait until Key Lime Pie comes out and see if they sort out the bugs otherwise I will root.

Kind of discouraging

root doesnt automagically improve the devices performance, its what YOU do with root access. oh, and what lag? not the tiniest bit of lag on my device. custom rom/kernel, and some optimizations. couldnt be happier. btw, mostly whatl root does is let you use root apps. you dont need root to flash custom roms/kernels. but you do need an unlocked bootloader. with root, you can control that rom/kernel, get to the devices main file system, change whatever you want, and otherwise be in complete control of your device.

I get my nexus 7 today, after a hour I rooted it, just for ad block plus and the ability to customize the navbar. Love root.

Blixz said:
I've tried out a rooted nexus 7 and to be honest didn't see a huge improvement so I've decided to wait until Key Lime Pie comes out and see if they sort out the bugs otherwise I will root.
Click to expand...
Click to collapse
There will most likely be more updates to 4.2 before Android 5.0 comes out.

I personally think it does make it better. It all really matters how you use your tablet and what you put in it like the Kernel you install. Roms it really doesn't matter really what you get but I have always been a big fan for CM since first getting the G1, nexus one, the HTC G2/Desire z and it has always been the fastest rom for me.
Sent on my rocken Nexus 7

simms22 said:
root doesnt automagically improve the devices performance, its what YOU do with root access. oh, and what lag? not the tiniest bit of lag on my device. custom rom/kernel, and some optimizations. couldnt be happier. btw, mostly whatl root does is let you use root apps. you dont need root to flash custom roms/kernels. but you do need an unlocked bootloader. with root, you can control that rom/kernel, get to the devices main file system, change whatever you want, and otherwise be in complete control of your device.
Click to expand...
Click to collapse
I had thought you needed SU access in order to flash a custom rom. Or is that just to use CWM which needs SU? Anyways if you unlock you must as well root it.....yes....!

Yeah as a few people have already said root alone will do mouthing for performance faux kernel, as far as I'm concerned, is a great addition to this great tablet.
Sent from my Nexus 7 using Tapatalk 2

I actually get a lot of performance lag. Might be from alot of email sync but still it shouldn't have a half second delay after lock screen and moving between screens etc.
And I thought I would need to root to get my bootloader unlocked? I'm sure it's easier for the nexus than my HTC One X. Which was kind of a pain.

Yes using different roms and or kernels will make a massive difference to performance and or battery life but thats determined by which kernels and roms you use some are built for speed others for battery. If you had searched the forum you would have found this :silly:

Root will break some apps.
Just wanted to mention that unlocking your bootloader and rooting will break a few apps for the Nexus 7. I was all gung-ho to root my Nexus the first week I had it. Then I discovered I could no longer stream cable tv to it with Time Warner Cables app. Google Wallet also wouldn't let me link any cards to it's app while rooted or with an unlocked bootloader. A quick skim of the forum shows that rooting breaks streaming functionality on other subscription video apps as well. Depending on how you use your tablet, this might not matter to you. I ended up going back to stock for now, just because I wanted to use these apps. There is probably workaround, but I just didn't want the extra work....around. I think the Nexus 7 ultimate toolkit might let you gain temp root, I don't remember for sure tho.

Rooting will not effect performance at all. Your just gaining access to the root directory. It's what you do after that effects performance. Also just rooting does not effect the wallet app at all, this is wrong information. Wallet does a root check for security purposes and will show "unsupported device" within the app after rooting. Ignore that, it is just a root notification. Cards add correctly and it functions correctly. I can't speak on the other apps mentioned, but ill take a stab in the dark and start at user error
Custom roms will definitely increase performance. Stock 4.2.1 is a bit laggy, I recommend flashing liquidsmooth and see the difference!
Sent from my Nexus 7 using xda premium

I stream movies using Flixster with my rooted N7. It's simple if you are rooted with Supersu. I go to settings in the Supersu app and uncheck Enable Superuser. After I finish streaming, I go back and enable it again.
Sent from my Nexus 7 using XDA Premium HD app

[Q] Nexus 4 Custom Kernel Help

Hi, I am a recent iPhone convert thanks to the Nexus 4. So obviously I am new to rooting, custom ROMS, and custom kernels. I am currently rooted and am running a recent CM 10.1 nightly. However, battery life isn't all that great.
A friend of mine told me that a custom kernel can drastically improve battery life without hurting performance. So here I am hoping that someone can help me. Can anyone recommend a good kernel that will improve battery life without hurting speed?
Also, what are the steps for installing a custom kernel? What about going back to stock in case I have to send my phone in for an RMA or something like that? Is that easy to do?
Thanks in advance for the help!

Try Franco or Harsh or trinity .
Custom kernels are more about under clocking a few things here and there to get best balance between performance and battery life thats and some tweaks which are generally inbuilt .
But tbh not all phone's are same what works for me and few others might not fetch u the same results, i've experienced this over my previous nexus device .
Some combo of ROM/kernel might work for u and not so well for other's i would say try out all the main stream kernels and some more if your'e feeling epxerimental give each kernel 2 to 5 days and see which u like the best.
Personally i've had good results with harsh kernel and franco and trinity .

berz said:
Try Franco or Harsh or trinity .
Custom kernels are more about under clocking a few things here and there to get best balance between performance and battery life thats and some tweaks which are generally inbuilt .
But tbh not all phone's are same what works for me and few others might not fetch u the same results, i've experienced this over my previous nexus device .
Some combo of ROM/kernel might work for u and not so well for other's i would say try out all the main stream kernels and some more if your'e feeling epxerimental give each kernel 2 to 5 days and see which u like the best.
Personally i've had good results with harsh kernel and franco and trinity .
Click to expand...
Click to collapse
Do you have one that you would suggest for a first time newbie? Also, what is the process for installing it and potentially uninstalling it back to stock?

Everything is easy to do. AS LONG AS YOU READ FIRST before doing anything You can start by reading the guides found here in the Nexus 4 General thread.
So far, the best for both performance and battery for me is Trinity kernel.
By the way, to install a custom kernel:
1. Install proper drivers for nexus 4 in your pc.
2. Unlock your bootloader.
3. Install custom recovery like CWM or TWRP Recovery
4. Start flashing your choice of kernels!
Sent from my Nexus 4 using xda premium

wtfshouldidonow said:
Everything is easy to do. AS LONG AS YOU READ FIRST before doing anything You can start by reading the guides found here in the Nexus 4 General thread.
So far, the best for both performance and battery for me is Trinity kernel.
By the way, to install a custom kernel:
1. Install proper drivers for nexus 4 in your pc.
2. Unlock your bootloader.
3. Install custom recovery like CWM or TWRP Recovery
4. Start flashing your choice of kernels!
Sent from my Nexus 4 using xda premium
Click to expand...
Click to collapse
Thanks for the advice! I am currently using CWM and have an unlocked boot loader. Is it as simple as downloading a zip, going into recovery, and installing the zip from "sd card"? If so, where can I find the zip for trinity? And how can I go back to stock in case something goes wrong?

There are post on xda and you could Google it. Just download it on your nexus and flash it
Sent from my Galaxy Nexus using xda app-developers app

strausd said:
Thanks for the advice! I am currently using CWM and have an unlocked boot loader. Is it as simple as downloading a zip, going into recovery, and installing the zip from "sd card"? If so, where can I find the zip for trinity? And how can I go back to stock in case something goes wrong?
Click to expand...
Click to collapse
If you want to be always safe and sure, then BEFORE flashing anything, go to CWM, choose backup and restore, then choose backup. That is called a nandroid backup. It might take a long time depending on how much apps you have. After the nandroid backup takes place, then you're free to flash the zip for trinity that you've downloaded.
I also suggest that you do backups often and delete old ones (you can delete old backups in the "backups and restore" part of CWM). So that incase anything goes wrong when you flash something, just go back to recovery mode, then restore your latest backup and you can undo your wrongs
Sent from my Nexus 4 using xda premium

wtfshouldidonow said:
If you want to be always safe and sure, then BEFORE flashing anything, go to CWM, choose backup and restore, then choose backup. That is called a nandroid backup. It might take a long time depending on how much apps you have. After the nandroid backup takes place, then you're free to flash the zip for trinity that you've downloaded.
I also suggest that you do backups often and delete old ones (you can delete old backups in the "backups and restore" part of CWM). So that incase anything goes wrong when you flash something, just go back to recovery mode, then restore your latest backup and you can undo your wrongs
Sent from my Nexus 4 using xda premium
Click to expand...
Click to collapse
So nandroid backups also backup the kernel?

strausd said:
So nandroid backups also backup the kernel?
Click to expand...
Click to collapse
bump. i also need to know the answer to this question.
EDIT: nvm found my answer, it backups the kernel too.
admins can delete this

imeem said:
bump. i also need to know the answer to this question.
Click to expand...
Click to collapse
nandroid backs up everything. it basically takes a snapshot of the state your device is in when you back it up, then restored your phone to exactly how it was before the backup.

Coming from HTC One S (and a whole lot of HTC family before that) and not having to deal with S-Off dilemma is a whole new free world for me (you can say i am institutionalized).
If I want to flash a rom and not the kernel included in it, can I just remove the boot.img file from the rom's zip and flash it? Or is that not a good idea?

justthefacts said:
Coming from HTC One S (and a whole lot of HTC family before that) and not having to deal with S-Off dilemma is a whole new free world for me (you can say i am institutionalized).
If I want to flash a rom and not the kernel included in it, can I just remove the boot.img file from the rom's zip and flash it? Or is that not a good idea?
Click to expand...
Click to collapse
no. you need to flash the whole zip. without a kernel, your device is an expensive brick. the kernel control pretty much everything and connects the hardware to the software. you can always flash another kernel after flashing the rom zip.

simms22 said:
no. you need to flash the whole zip. without a kernel, your device is an expensive brick. the kernel control pretty much everything and connects the hardware to the software. you can always flash another kernel after flashing the rom zip.
Click to expand...
Click to collapse
Thanks for the reply.
Are all kernels pretty much compatible with all roms?

justthefacts said:
Thanks for the reply.
Are all kernels pretty much compatible with all roms?
Click to expand...
Click to collapse
all nexus 4 kernels are compatible with all nexus 4 roms. if you flash a non nexus 4 kernel onto your nexus, you will most likely brick it.

Sounds great. This will be my first Nexus experience. Love this forum already. A very mature crowd.

(Q) what benefits do u see in root nexus 4 5.1?

Just for curiosity, I have a stock nexus and my lasts phones I usually rooted to actualize with new rom, because always them was behind. Our phone is been actualized stock software until now, and I want to know from who rooted their nexus which benefits can u see of root our nexus 4?
P.s: if moderators not see that is a relevant post , can delete, just let know me first.
Thanx
Enviado de meu Nexus 4 usando Tapatalk

Benefits are the same. After rooting you can install cutom roms. You get better battery life, USB fast charger, App opps, UI customization etc. But you will not get direct updates from Google.

So I just flashed stock image 5.1.1 and my battery life really took a hit. What custom rom has the best battery life these days? I am definitely not a power user, I just want long battery life.

amarprat87 said:
Benefits are the same. After rooting you can install cutom roms. You get better battery life, USB fast charger, App opps, UI customization etc. But you will not get direct updates from Google.
Click to expand...
Click to collapse
Almost agree except for "After rooting you can install cutom roms". Rooting has nothing to do with custom roms. In order to flash a custom rom you need a custom recovery and an unlocked bootloader
Back to topic, I root my device to get my freedom. There are noumerous apps (wich I use) that require a rooted device. So, for me no root, no joy.
cheers

dirtfarmer7 said:
What custom rom has the best battery life these days?.
Click to expand...
Click to collapse
You can try SimpleAOSP Rom by snakeater. Install Hellscore Kernel or modified Semaphore kernel by Snakeater. Use conservative governer with touch boost to get better battery life.

Best Kernel for Stock (Non-Rooted)

I used to be an avid ROM flasher, changing ROMs daily on my old Moto X. Now that I'm using Android Pay religiously I need to keep my phone non-rooted, but would still like to run a custom kernel. I have been looking at FrancoKernel and ElementalX (sp?), but not sure what is best for the stock ROM without any tweaking (as most kernel tweaking apps need root). What's the community think?

grimez said:
I used to be an avid ROM flasher, changing ROMs daily on my old Moto X. Now that I'm using Android Pay religiously I need to keep my phone non-rooted, but would still like to run a custom kernel. I have been looking at FrancoKernel and ElementalX (sp?), but not sure what is best for the stock ROM without any tweaking (as most kernel tweaking apps need root). What's the community think?
Click to expand...
Click to collapse
Franco kernel
Flash it forget it
Cheers

I would also say Franco...

Never used Franco so I cannot comment on it. I use ElementalX, stock, rooted and it works awesome.
Sent from my Nexus 6P using XDA-Developers mobile app

Got Franco's kernel flashed with TWRP as recovery and everything else stock. Can already see battery life improvement, can't wait to see how it compares in the long run.

I hate using Franco Kernel.
For some reason everytime I use it I get more battery life then I should, and everything works faster than stock. I don't plug in my phone more than I have to. It's just the worst kernel out there if you want low OST and crashes.

Didn't think that you can replace boot.img on an uprooted phone.

grimez said:
I used to be an avid ROM flasher, changing ROMs daily on my old Moto X. Now that I'm using Android Pay religiously I need to keep my phone non-rooted, but would still like to run a custom kernel. I have been looking at FrancoKernel and ElementalX (sp?), but not sure what is best for the stock ROM without any tweaking (as most kernel tweaking apps need root). What's the community think?
Click to expand...
Click to collapse
I'm rooted with custom ROM and systemless root and Android Pay works 100%. Can add cards and pay at terminals without issue.
Just a little FYI.
Sent from my Nexus 6P using Tapatalk

Can we change the kernel if not rooted? If yes, can you share the procedure?

GroovyGeek said:
Didn't think that you can replace boot.img on an uprooted phone.
Click to expand...
Click to collapse
dharish said:
Can we change the kernel if not rooted? If yes, can you share the procedure?
Click to expand...
Click to collapse
Root has nothing to do with the ability to install a kernel. All that's required is TWRP recovery, which in turn requires an unlocked bootloader.
http://forum.xda-developers.com/nexus-6p/general/guides-how-to-guides-beginners-t3206928