I've tried searching for these things, but all the info seems to be very fragmented.
If someone can give me a simple answer, I would greatly appreciate it.
Kernel - Do I need to flash a new one when installing a new ROM, or is it already in there? Do I just flash it by having a .zip on my sdcard?
Recovery - is this just a shell for bootloader (terminology from the winmo days i guess)? Are there differences, one better than another?
I'd like to install the stock 2.2 ROM that netarchy released, but there is a lot of talk about kernels as related to wifi and FPS, so I wanted to see what that's all about.
Thanks.
Kernel Answers:
No. When flashing a new rom a kernel is included. Kernels are packaged up in the boot.img files inside the rom.zip. Now, with HTC Sense phones there are two types of kernels. HTC kernels and Android kernels. HTC builds their phones in such a way that a standard Android kernel will not work. This is why we need to wait for the kernel source code from them. It also depends what OS is on the device. If you have a stock Sense rom it will use a different kernel than an AOSP rom such as CyanogenMod. So as an example, you are unable to use any CM6 kernel with Sense or vice versa.
My point is this. Be careful. If you want a modified kernel make sure it is for your rom or is compatible with your rom.
Recovery Answers:
No. Recovery is different than the bootloader. Recovery is a mode built into the phone so that, assuming something goes wrong and Android doesn't boot, you can boot into recovery and flash different files. This is only meant for HTC employees however at XDA we always find a way to use this recovery for our own purposes. We take HTC's recovery, erase it and flash our own recovery over it. This allows us to backup and restore our phones, flash new files to it, wipe it, etc.
So for your question. You can use the Stock 2.2 rom and Netarchy's kernel and it should work fine. Just be careful because it is a 2.6.29 kernel. The stock kernel now is 2.6.32 so some things may or may not work properly with it as FroYo was designed to run on a 2.6.32 kernel.
Thanks a bunch for the info!
So if I do the "Volume Down + Power" thing, that goes into phones native recovery menu?
Also, if the phone is rooted (via toast's or simple root), will it then have a different recovery process?
EDIT: As has been pointed out, this thread maybe better served in the Q&A section. Mods, please move this if you feel it's necessary.
Related
I have done some searching and found that I need to install a custom kernel on my EVO to get native CIFS/SMB support (ie so Rockplayer can play movies on my NAS: one of my endgames).
I have already rooted my phone (unrevoked), and have started looking around for a ROM to load (haven't picked one yet).
I have not been able to find non-developer instructions for doing anything with a custom kernel besides that it will be needed for custom drivers (why not have drivers like on a desktop where they don't need a kernel recompile???). I mention this because I plan to start with a compiled kernel, not be in a development environment creating a new kernel.
Do custom ROMs typically come with a kernel at all? I'm not clear where the two separate in terms of deployment, but I think the answer is that custom ROMs do not have to include a kernel of any kind, but it is possible to bundle them somehow.
I am looking for a n00b friendly guide to install a custom kernel (ie boot to fastloader, select the kernel, tell it go, and reboot, run this command, do happy dance), maybe a recommendation for a specific custom kernel, and hopefully a reference to a ROM that comes with a custom kernel that has CIFS/SMB support already baked in.
I looked in my fastboot/bootloader and I didn't see an option for kernel, but I'm not sure what it might be called in that scenario if it isn't called "load kernel"
You'll be flashing kernels the same way you flash roms. Boot into recovery using Rom Manager, wipe cache and dalvik, flash zip from sd, reboot. All the custom roms you find here will come with a kernel baked in. Most of the Sense Roms are using HTC #15 or some version of Netarch. Savaged Zen kernels are great for AOSP roms. Every phone responds a little differently to different types of kernels. Just play around until you find something that works for your particular application.
In flashing roms, I notice that devs are including kernels in the .zip. It appears each dev has their favorites. Without debating which kernel is the "best", my question is can I switch a Zimage (which I assume is the kernel) with another of my liking? Or, if I'm running a particular kernel of my liking, can I flash the Rom without the included Zimage?
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Vegasden said:
In flashing roms, I notice that devs are including kernels in the .zip. It appears each dev has their favorites. Without debating which kernel is the "best", my question is can I switch a Zimage (which I assume is the kernel) with another of my liking? Or, if I'm running a particular kernel of my liking, can I flash the Rom without the included Zimage?
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Click to expand...
Click to collapse
You should be able to flash a kernel, either through CWM or ODIN without problem.
sk63 said:
You should be able to flash a kernel, either through CWM or ODIN without problem.
Click to expand...
Click to collapse
I realize that. My question was in reference to flashing a rom (which all have a kernel included). Can you switch the Zimage inside the rom .zip prior to flashing...or can I just delete the Zimage inside the rom and flash it without one? I'm trying to avoid the two steps of flashing a rom, then flashing a kernel I prefer.
Ah, I've always just flashed the ROM, then flashed the kernel then rebooted out of CWM. Be nice if there was a utility where you give it kernel and rom and tell it to go, might be a nice feature for ROM Manager to add.
So i am new to Samsung (coming from a launch evo) and watched the QBKING77 videos and rooted and flashed Calkulins rom pretty easily. So far pretty simple but I have a question.
I am on stock EL29, What confuses me is the list of all the different modem .zip/.tar that are listed in the Caulkins thread. I couldn't really find a thread or video explaining what the difference is between the many different modems, or what the heck a modem is even. or if i should even worry about those at all. Should i just stick to the stock kernel that came with the rom? If i do decide to change the modem do i just flash/odin and im all set? or do i have to re flash the rom?
From what i learned so far, the kernel and phone radios are one in the same right?
Modem = radio. Also known as baseband under your settings - about phone. Modems are flashed independent of a ROM or kernel.
You can mix and match anytime you'd like. If you have solid service on EL29, no need to switch.
You can use any modem on any gingerbread or ics rom. If using a GB rom, you can't use an ics kernel and vice versa.
Hope that helps
.zip is for flashing via Clockwork Recovery. .tar/.bin is for flashing via ODIN. Most importantly it's vital to read and reread everything and also ask any questions before flashing, like you're doing now. I make Nandroid backups anytime I'm about to make ANY changes. Good luck.
Also keep in mind that anything with F in the version (ex FC07) is an unofficial leak. The latest official is EL29, which you are already on.
As a good practice when I switch modems, is to update PRL and profile then reboot.
Components come in the following packages. These packages will come either in .zip or .tar/.bin form.
1. Modem (Always separate, can use any Modem with any rom)
2. ROM (With Kernel or Without Kernel)
3. Kernel (With CWM or Without CWM, use ICS kernel for ICS rom. Use GB kernel for GB rom)
CWM = Flash .zip and make Nandroid backup
Odin = Download Mode flashing tool that can flash .tar/.bin. It can be used
Don't go around flashing your radio all the time. It can be dangerous and very brick easy.
Thank you guys! This is the info I needed. I'm sticking with EL29 for now since I'm having zero issues on the radio side. And I wasn't going to flash ANYTHING via Odin until I learned more about how it all worked.
Do I need to manually update the kernel when installing Calkulin's 2.9.2 ROM?
I installed Calkulins 2.9.2 ROM quite a while back and have been happy with it. I believe I am on the stock EL29 modem (my baseband version says S710.10 S.EL29).
I am confused about the kernel. When installing Calkulin's ROM, did I also install the "Rogue" kernel? Or did the kernel not change from the stock kernel that was on the phone from before.
From what I have read I believe that if I am still on the stock kernel then I would not be gaining the battery life benefits of the ROM because the scripts installed by Calkulin's ROM would not be running.
Currently my "kernel version" says "2.6.35.7-SPH-D710.EL29-CL852097". I believe that this is the stock kernel from Sprint. If I need to install the "Rogue" kernel, (1) where do I get it from and (2) how do I know I am using the right one for Calkulin's version 2.9.2 (and not V 3.0)?
Thanks for any assistance you can provide,
Kevin
You can find kernels in the wiki in the stickies in dev section. If you turn your phone off completely( no light on the buttons at them bottom). Then you push and hold volume up and power at the same time. Wait for it to go into recovery. Does it say e3 with blue letters or is there a green backround?
Sent from my SPH-D710 using Tapatalk 2
When I go into recovery on the top it says "Rogue ET Recover 1.1.2 (CWM v5.0.2.7)" and the background image says "Team Rogue". I wasn't able to find something that told me what kernel I was on.
Correct me if I'm wrong, but I believe you're on what's called a repacked stock kernel...its the stock el29 kernel with the cwm recovery added to it.
Sent from my SPH-D710 using XDA
Johnny - thats the thing I dont know; I am unsure how to tell what kernel I am on. I have always been under the impression that when I installed Calkulin's 2.9.2 ROM, that it also installed the "Rogue" kernel. But I am now under the impression that I may be on a "stock" kernel.
From what I understand about the ROM, the battery saver tweaks do not work for "stock" kernel. I never quite understood what a "repacked" kernel is.
specialkb01 said:
Johnny - thats the thing I dont know; I am unsure how to tell what kernel I am on. I have always been under the impression that when I installed Calkulin's 2.9.2 ROM, that it also installed the "Rogue" kernel. But I am now under the impression that I may be on a "stock" kernel.
From what I understand about the ROM, the battery saver tweaks do not work for "stock" kernel. I never quite understood what a "repacked" kernel is.
Click to expand...
Click to collapse
K. So there's a couple of things going on here. Let's get you some definitions.
Kernel: Essentially the backbone of the operating system. There are different stock kernels for different versions of Android (one for GB and another for ICS). A stock kernel comes with stock recovery. It is not a good idea to flash anything using this recovery (in some cases it is actually blocked so you can't).
CWM: Clock Work Mod. The original version from Chris. It is considered a "repacked" kernel. It stands apart from a regular kernel because it has a custom recovery built in. There are a few other things packed into it but the main difference is the custom recovery. The EL26 CWM is commonly referred to as stock CWM (not a stock kernel though).
Rogue: Team Rogue is the most common one you'll see for our phones. They took CWM and customized it further. They also developed custom recoveries based if the leaked ICS kernels. There was something causing bricks in the kernels they created, unfortunately we can't quite figure out why until we have source.
If you are seeing Team Rogue when opening recovery you currently have a "customized custom recovery kernel".
If you are flashing anything GB you're ok with what you have. If you're flashing ICS you'll need to use the EL26 CWM.
How this clears things up a bit.
So I cut my Android flashing teeth on the original HTC Magic, then to a Desire and Galaxy Tabs on the tablet front. Even cooked a few roms back in the Magic days (although was little more than mashing bits into an update.zip if I'm honest)
Anyway, I'm used to the scenario where, once you've got a viable recovery, you can thenceforth flash and backup/restore whatever you want without any need to plug the thing into a computer and do any messy fastboot stuff. I can't find a clear indication, but the vibe I'm getting is that in Sonyland one must always flash the boot.img of a new rom before going into recovery to install a new update.zip. is this right, or am I taking instructions designed for first timers too literally?
When you flash your first rom, let's say CM9, you will need to install FXP's CM9 boot.img(AKA kernel). Then if you wanna update your CM9 rom(IE. From Nightly 1 to nightly 2), you can use the same boot.img. BUT, if you want to flash stock based rom, like Arconium ICS, you will need stock kernel(Sony stock kernel, DoomKernel), if you want to flash stock based GB rom, you'll need stock based Gingerbread kernel(DoomKernel for GB f.ex).
When you go to the rom's thread, the developer always tells what kernel to use. If you have one of the listed kernels, you're good to go, just flash the rom itself, and no need to flash kernel again.
I hope I was clear enough
No, that's a valid question. I don't recall the explanation (if any) but recovery on Sony's phones can't modify the kernel for some reason.
While on other phones like your old htc, and even most samsung phones, it is possible to update the kernel from recovery.
I have a GSM Galaxy Nexus and I am currently using 4.2.2 Cyanogen Mod released in April 2013.
It has the following Kernel
3.0.31-cyanogenmod-g64e9296
I have flashed ROMs many times mostly CM ROMS.
I want to try changing kernel to improve battery life and check what kernel changes actually is all about.
Since I havent done it earlier, I want answers to following questions:
1) Is it safe to change my kernel to another one? I want to install http://forum.xda-developers.com/showthread.php?t=2115590 or maybe someone can tell me a better one with focus on improved battery life.
2) What if the above kernel screws up? can I recover the old kernel back?
3) Is kernel flashing Permanent or any ROM I flash will have it's own kernel?
4) Just in case my kernel screws up, I have a full TWRP backup as well, would flashing that change my current kernel to old one that came with cyanogenmod last ROM?
Thanks.
You can pretty much flash any kernel you want. Just make sure the kernel is made for the version of Android you are on. If something goes wrong, you should be able to flash your ROM again and get back to normal. ROMs come with their own kernels so every time you flash a ROM, you will get the kernel that comes with it. But the best way to recover from a screw up is to restore a nandroid from your recovery.
jsgraphicart said:
You can pretty much flash any kernel you want. Just make sure the kernel is made for the version of Android you are on. If something goes wrong, you should be able to flash your ROM again and get back to normal. ROMs come with their own kernels so every time you flash a ROM, you will get the kernel that comes with it. But the best way to recover from a screw up is to restore a nandroid from your recovery.
Click to expand...
Click to collapse
Advanced restore should work, no need to restore the whole thing, just system.img and boot.img should do the trick.
Sent from my Nexus