Galaxy SII XXLQB kernel?

  • Replies:6
  • Forum posts: 7

Aug 28, 2012, 11:26:33 PM via Website

I've been the owner of a Galaxy SII (International version and off-contact) for more than a year and I finally decided to root it and flash CM9 and CM10 when it gets a stable version. I've never rooted an Android device before, in fact my Galaxy SII is my first Android phone (it's probably not relevant but I have jailbroken an iPod Touch 4G), but I know what rooting is, I am aware of the dangers and the benefits etc.

For the past weeks I've been reading a lot about how to root my device, flash ROMS, get CWM recovery etc and today I read AndroidPIT's article on how to root the Galaxy SII ( ). The instructions are pretty straight forward so I have no problem understanding them but I had another problem: I couldn't find a kernel (insecure and secure) that matched my device's build number's last 5 characters which are XXLQB. After some quick research I came across the Siyah kernel ( ) which matches my build number and I just wanted to ask if it is OK to use it instead of the kernels at XDA and if there is any difference/disadvantage. Could a kernel for my device be released at XDA if I wait for a few weeks?

One more thing; the siyah kernel doesn't state if it's "insecure" or "secure" so I don't really know if I can use it or how I should use it. Actually, can someone explain to me what insecure and secure mean when it comes to custom kernels? Thanks a lot in advance guys.

PS: My phone's running ICS 4.0.4, you could read that in my info though.

— modified on Aug 28, 2012, 11:30:35 PM

  • Forum posts: 66

Aug 31, 2012, 5:55:29 PM via Website

Hi Anna, as far as I know, you do not have to flash the same build number as the one you are presently on. What matters is the type of kernel and the rom you intend to use with it. Some ROMs are touchwiz based or stock based, then you need to flash a TW based kernel. Others that are CM based need a CM kernel. For example, my Note was updated OTA to ver DXLR5 but I flashed a custom kernel for it. Generally, I use notecore when I use stock TW Samsung ROM but I switch to Thor Kenel for when I am on CM9 and its derivatives.

The advantage of XDA kernels are that they are required to publish their source codes, hence people can check for malicious or dangerous commands.

  • Forum posts: 7

Aug 31, 2012, 6:11:01 PM via Website

The kernel doesn't have to match my current kernel? But the AndroidPIT post explicitly states to find one that matches your phone's build number and my phone's build number matches my current kernel. To quote the actual post "At the bottom of the page you will see a field that says "Build Number". You need to write that number down and note the last 5 letters/numbers. Based on what you wrote, go to the link HERE at XDA developers, and download both the insecure AND secure kernals that match your phone." To be honest I don't know that much about that stuff and I really can't understand why there are different kernels for each different build number. I mean, what difference does it make?
And do you mean I have to decide on what kernel to download based on the ROM I wanna flash? Like I said, I wanna flash the stable version of CM9; what kernel do I need to do that?
And can you please explain to me what the difference is between a "secure" and an "insecure" kernel?

  • Forum posts: 66

Aug 31, 2012, 6:27:37 PM via Website

I will clarify in a bit. Sorry i'm doing this on my phone. Will post when I get home to a proper keyboard. Give me a few mins. :)

  • Forum posts: 66

Aug 31, 2012, 7:36:25 PM via Website

Hi Anna, okay, gonna try to do this again, sorry for the unclear post, was doing it from my note. Hopefully this will be better.

My reply was for the final kernel you would be using and not the one you will use to attain root access. Sorry if my post was unclear. One caveat though, I am no where near dev level skills, i have just rooted and flashed roms on my devices and some for phones of my friends. My experience is from Galaxy S, Note, Galaxy Nexus, Kindle Fire and the Transformer Prime. No experience with the GSII although the process is the same for the Samsung Devices.

To gain initial root, yes, you need to use a pre-rooted kernel that matches your build number. But it does not refer to the Siyah kernel, it refers to a stock pre rooted kernel. Look for it in this thread (The instructions for rooting are there as well.)

The build numbers are actually version numbers with very minor changes between kernels that are release close to each other - read the version numbers as 1 to Z it's like A being equal to 10, so the numbering system is something like 1, 2, 3... 8, 9, A, B, C and so on. And only worry about the last numbers/letters, LQB in your case.

After rooting, you may now flash CyanogenMod, this is where my previous post applies. When you already have root access and plan to flash a ROM, you no longer have to flash and use a kernel with the same build version as your original kernel or stock rom. When you follow the instructions to flash CM9 on their Wiki, that will flash a new kernel on your device (the CM9 Kernel). This is where Siyah Kernel will come in, if you want to replace the "stock" CM9 kernel with it. That is if you want to do performance tweaks such as overclocking, undervolting etc. But for as a daily driver, the kernel CyanogenMod comes with is very stable and should be more than sufficient.

As to secure and insecure kernels, I THINK (i am not sure) it refers to simply having the latest version with the security issues from the last version patched relating to the networking functions. Or it could be a reference to the super brick bug which exists on the GNote and GSII stock kernels.

One last warning though, rooting and flashing may require you to do data wipes (data, cache and dalvik cache wipes) and as far as I know there is what is known as a super brick bug in the Note and the GSII (i think) that can brick your device if you do a wipe on a stock or an unsafe kernel. I bricked my note a while back flashing an ICS leak. Although the devs have come up with safe kernels and instructions, so if you take the plunge, follow their instructions to the letter. (if it says perform a "reboot to recovery" function, don't skip it) :) good luck rooting and happy flashing.

In case, you have anymore questions, I'll try my best to help.

  • Forum posts: 7

Sep 3, 2012, 4:32:12 PM via Website

Hey, thanks a lot :)
I'm on holidays right now so I'm writing this from my phone and I think I found the right kernel! I'll look into it more next week when I'll be home and I'll let you know how it went or if I have any more questions. Thanks again.

  • Forum posts: 1

Dec 27, 2013, 8:38:55 AM via Website

I have a SM-T210R samsung galexy tab 3 (wifi) rooted with stock rom and I was wondering if its a insecure kernal when I got it because thats what people are saying and I have cwm recovery and I can flash mods so would it be safe to flash custom roms