First time flashing a kernel, some quick questions - Galaxy S 4 Q&A, Help & Troubleshooting

Hi everyone
I have a rooted stock Galaxy S4 I9505 (4.4.2) and TWRP installed. For the last few weeks, my phone had a lot of kernel wakelocks which I couldn't stop. This could be fixed by installing a new kernel, right? I wanted to try that anyway.
I think I read the relevant FAQs, but this is my first time flashing a kernel, so just to be sure I have a few questions:
Does anyone have experience with the KT-GSG4 kernel? Do all custom kernels have the basic functions of stock kernels (plus some features), or will I lose some functionality?
Can I just flash the kernel, without changing the stock rom and keeping my files/settings etc.? If I do something wrong, can I just restore via nandroid backup?
Do I just have to go into TWRP recovery, click install, choose the kernel zip file, install it, wipe caches and reboot?
Thanks a lot!

Ktoonsez is a great kernel dev. So the kernel should be fine.
A custom kernel generally offers more customizability. I don't know what features you might from stock kernel you might lose.
If the kernel is for touchwiz, then you can probably flash it on a touchwiz rom. Just make sure it is for the same android version.
I haven't flashed any kernels on a stock touchwiz rom so I can't tell you the flash procedure. It may be different from custom roms due to knox and other stuff.

Related

Stock ROM Custom Kernel

I've been searching the forums to see if there is a custom kernel that you can flash over the stock rom. My friend did this to his motorola droid so that he could overclock the processor, so I assume someone has developed a similar kernel for the hero. Is this possible/does this kernel exist? I am aware that there are custom roms that allow for overlocking, but all I really want is a custom kernel.
Pick any kernel you want as far as I understand it. Of course, make a Nandroid first, then flash the new kernel. If you have any major problems with it, you can just restore the Nandroid, which will return you back to the stock kernel. I am about to embark on this same journey myself tonight. I'm going to use this one here - http://forum.xda-developers.com/showthread.php?t=705074 . Good luck to you in your endeavors.

[Q] Rooting, flashing custom rom but necessary to flash a kernel as well?

Hi,
Quick question I am still having trouble wrapping my head around the concept about kernels. I am planning to root my nexus 4 and flash a custom rom (purity rom) but am i required to also flash a custom kernel? Or am I suppose to leave the kernel as is?
Thanks!
Next123 said:
Hi,
Quick question I am still having trouble wrapping my head around the concept about kernels. I am planning to root my nexus 4 and flash a custom rom (purity rom) but am i required to also flash a custom kernel? Or am I suppose to leave the kernel as is?
Thanks!
Click to expand...
Click to collapse
Depends upon your requirement .
As an example i use Fast USB charge a lot and is not available in any custom rom .
I also use Headphone volume boost which is yet again a kernel level change.
I would suggest you to use a custom kernel since it also gives better battery than stock .
If you are happy without it then forget about kernels . And in case u plan on flashing one make a CWM backup just in case.,
You could if you want to since you're already flashing custom roms. However, most custom rom come with custom kernel, so when you flash a custom rom it will replace your kernel with it's own. You can manually flash back your stock kernel if you want, using fastboot, but there is a flashable package as well in the Dev section.
Just know that due to codes and drivers, different kernels work with different roms. If you flash a 4.3 kernel to a 4.4 rom, it might lack certain necessary driver, such as PRIMA, so your wifi will no longer work. (You can fix this by flashing dePRIMAtor). CyanogenMod use Code Aurora Forum drivers, so if you use a kernel that doesn't support CAF, the screen colors will be messed up (you can lash a colorfix package which replace it with the non-CAF liboverlay.so).
A lot of people get wrapped too far up into flashing kernel and thinking it determine everything (performance + battery life) in their phone. As much of a heavy flasher that I am, I am willing to bet that you generally get the best battery life and stability just running stock. I did my own trial for this, with stock rom and kernel, the phone staying cooler and screen on time was longer. This is just my personal experience, it varies for each person.
But I mainly use custom kernel for features. Such as kernels that incorporate Faux color and sound, this allows changing their settings for much a better screen color and making the speaker louder. I also use the sweep2wake/sleep feature to turn on and off the screen.
If you intend to use custom kernels, I recommend using TricksterMod, it's the best app for modifying kernel settings.
Also just to mention this ahead of time, it's against XDA rules to make threads about what is the best rom/kernels.

[Q] Firmware Updates, Rooting, Backing Up, Custom ROM Questions

Sorry for the noob questions. I just don't want to mess it up.
I plan to root shortly. I've watched a few YT vids, so I'm confident about doing that.
I'd like to about the order of doing things, if that makes sense.
At the moment, I've not downloaded the OTA firmware updates, so it's basic KK 4.4.4. But, I downloaded via SamMobile, the latest KK ROM (N910FXXU1ANK4_N910FBTU1ANK2_BTU)
Am I correct in thinking, I should reformat the phone (I've got nothing on the phone I want to keep), install the ROM from SamMobile via Odin (to be fully up to date with KK), then root and install TWRP, create a backup.
Then I'm free to install any custom ROMs, update to Lp?
Speaking of custom ROMs, at the moment I'd prefer to stick with KK, until Xposed is sorted and is easy to install when using Lp.
Without trying all the custom ROMs out there, do any support the fingerprint scanner, S Pen, Multi Window, S Health and the HRM or would I loose some/all of those features?
If in the future I upgrade to Lp, is it necessary to download/flash the latest stock ROM (to get the latest FW updates/fixes/security patches etc), before I installed a custom Lp ROM?
Thank you for any help and advice
Does anyone have any answers, before I try it and blow up my phone in a massive fireball?
You're pretty much such right on the above steps. Some (me included) prefer Phils CWR rather than TWRP as a custom recovery. Fair enough to stick with KK, but LP working ok with Xposed now, assuming you're using a custom rom. There are two distinct types of custom ROMs. Those based on touchwiz and those that aren't. The ones based on TW will be called things like BOD2 or BOE2 for LP or ANK2 for KK (like the one you pasted above). Other ROMs will be based on AOSP. The TW ones will work with the s-pen, fingerprint etc. The AOSP ones won't. You can go straight to LP custom from KK, you don't need to flash via a stock LP ROM but it doesn't harm to do so. The custom ROM installation instruction will often provide you with an extra bootloader/modem file to flash if you are coming from KK or a different version of LP. Stock ROMS do include bootloader and modem, custom ROMs generally don't.
Good luck
EyeTech said:
You're pretty much such right on the above steps. Some (me included) prefer Phils CWR rather than TWRP as a custom recovery. Fair enough to stick with KK, but LP working ok with Xposed now, assuming you're using a custom rom. There are two distinct types of custom ROMs. Those based on touchwiz and those that aren't. The ones based on TW will be called things like BOD2 or BOE2 for LP or ANK2 for KK (like the one you pasted above). Other ROMs will be based on AOSP. The TW ones will work with the s-pen, fingerprint etc. The AOSP ones won't. You can go straight to LP custom from KK, you don't need to flash via a stock LP ROM but it doesn't harm to do so. The custom ROM installation instruction will often provide you with an extra bootloader/modem file to flash if you are coming from KK or a different version of LP. Stock ROMS do include bootloader and modem, custom ROMs generally don't.
Good luck
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Thank you very much, that's been a great help Respect to the People's Republik of Mancunian :good:
A TW ROM sounds the best option for me at this time.
A few more Q's if you don't mind (or anyone else).
1. Is it worth installing a pre rooted stock ROM (for the 910F), so I can get any possible OTA updates (KK or Lp) or is it nothing to worry about?
I'm not sure if any exist at the moment for the 910F?
2. Is it best to just install 910F based ROMs? (I'm thinking about the telephone side of things, connecting to UK carriers)?
Thank you.
0-0-0 said:
Thank you very much, that's been a great help Respect to the People's Republik of Mancunian :good:
A TW ROM sounds the best option for me at this time.
A few more Q's if you don't mind (or anyone else).
1. Is it worth installing a pre rooted stock ROM (for the 910F), so I can get any possible OTA updates (KK or Lp) or is it nothing to worry about?
I'm not sure if any exist at the moment for the 910F?
2. Is it best to just install 910F based ROMs? (I'm thinking about the telephone side of things, connecting to UK carriers)?
Thank you.
Click to expand...
Click to collapse
No prob. Yeah. I agree - go for a TW ROM. As for your questions:
1. No. OTA updates just take you from one stock ROM to next version of the stock ROM. OTA updates don't work well, usually failing, once you have rooted and maybe installed custom recovery. You can easily stay up to date without OTAs by just re-flashing with a new custom or stock ROM release. For me, the only reason to use a custom rom at present is to use Xposed (mostly to change DPI for different apps and also to add the symbols on the stock keyboard, oh and also to run a non-ads environment). If I was staying on KK I would have stayed on stock, rooted and then installed a custom recovery and Xposed. Currently Xposed is only compatible on the Note 4 with Lollipop if you are using a deodexed (custom) rom. All stock ROMs are ODEXED, and hence not compatible with Xposed (for now).
2. Yes. Stay away from ROMs for other variants (like the 910G). They're not compatible.
When you pick a ROM, ask questions in the ROM thread. It will be more read than these Q&A areas.
EyeTech said:
No prob. Yeah. I agree - go for a TW ROM. As for your questions:
1. No. OTA updates just take you from one stock ROM to next version of the stock ROM. OTA updates don't work well, usually failing, once you have rooted and maybe installed custom recovery. You can easily stay up to date without OTAs by just re-flashing with a new custom or stock ROM release. For me, the only reason to use a custom rom at present is to use Xposed (mostly to change DPI for different apps and also to add the symbols on the stock keyboard, oh and also to run a non-ads environment). If I was staying on KK I would have stayed on stock, rooted and then installed a custom recovery and Xposed. Currently Xposed is only compatible on the Note 4 with Lollipop if you are using a deodexed (custom) rom. All stock ROMs are ODEXED, and hence not compatible with Xposed (for now).
2. Yes. Stay away from ROMs for other variants (like the 910G). They're not compatible.
When you pick a ROM, ask questions in the ROM thread. It will be more read than these Q&A areas.
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Thank you again, I appreciate the help

Which kernels work on Lineageos?

Which kernels work on Lineageos? I'm interested in flashing vegito but I'm unclear if it works? It says to flash over only stock kernel, which lineageos doesn't have, but would it work if I flash stock kernel of lineageos first, then flash vegito?
lightningglasses said:
Which kernels work on Lineageos? I'm interested in flashing vegito but I'm unclear if it works? It says to flash over only stock kernel, which lineageos doesn't have, but would it work if I flash stock kernel of lineageos first, then flash vegito?
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ElementalX, vegito and quark kernels should work on Lineage OS without issue (though still check their respective pages!)
By flashing only over the stock kernel, the instructions usually mean only flash over the kernel that originally came with the ROM. I imagine it's a bit confusing given the Motorola ROM kernel is also regarded as the stock kernel, but in this case, the 'stock kernel' refers to whatever kernel the ROM you flashed came with. (As an aside, don't try to flash the Motorola kernels on custom ROMs...)
Lineage OS, as with other custom and stock (Motorola) ROMs come with their own kernel included, which you replace when you flash the custom kernel. A reason for requiring that you flash over the stock (originally coming with the ROM you've flashed) kernel only appears to be because custom kernels modify the ram disk of the kernel, which other custom kernels will be incompatible with and may lead to random issues. The stock (in this case, the original ROM kernel) is clean and has no modified ram disk, so should be stable, and thus suitable for flashing a custom kernel.
If you have the original Lineage OS kernel already, then you can flash vegito in TWRP. I'd recommend taking a TWRP backup of your system and of your boot partition before flashing. The boot partition should contain your kernel as it was, so if it's clean, you can revert back from vegito by flashing the boot partition backup. And the system backup is just in case anything happens!
Alternatively, a dirty flash of your current Lineage OS build may flash an original kernel if you don't have one already.

Safestrap and custom

I know that you can only flash stock roms from safestrap on cid11 but isnt there a way to flash nearly stock android with(out) root (6.0/5.0) on the cid11? I mean like changing the appearance of the os and the apps and nothing more.
You can flash any stock-based ROM that doesn't require a custom kernel.
For example, you CAN flash Alliance, Rick's ROM, jrkruse's ROMs, etc. These change some aspects, but only things that the stock kernel allows.
You cannot flash cyanogenmod, dirty unicorns, etc, because these need a non-stock kernel.

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