Flashing ROMS, Kernals, Radios

[truthhunter]

Some backround info: I am a newbie having just transitioned from my Blackberry to a Gnex. Reading these forums and thanks to WUG's auto unlock / rooting toolkit I found the courage to unlock and root my phone. I've read everything I could find on using ROM Manager, ClockworkMod Recovery. My paranoia has resulted in backing up my applications via Titanium Backup and My Backup.

I am reading about ROMs with different kernals, updated radios, etc. I am looking for answers to these questions in relation to using ROM Manager since I am trying to understand the limitations of that application. Questions -

Kernal flashing:

1. When you flash a new ROM via ROM Manager, is a new kernal also installed? If so, is the new kernal uninstalled when you go into flash back to the original stock ROM?

2. If a new kernal is not installed when flashing a ROM, or if you choose to flash a new kernal is that something which is done in ROM Manager?

3. When using ROM Manager to back up an existing ROM, is the kernal also backed up?

4. Assuming the kernal is not backed up (question #3), how to you recover the stock kernal (or any previously uninstalled kernal)?

5. When recovering a prior ROM, do you flash the ROM first, then the kernal?

ROM Manager Backup & Restore:

1. When restoring a ROM from ROM Manager, does it automatically clear the various caches (user data and davlik) before restoring? Do any caches need to be cleared prior to restoring a ROM?

2. When using ROM Manager to download (via the download ROM button), then install via the "Install ROM from SD Card" button, it flashing a new ROM as simple as clicking the button? I've seen comments about clearing caches. Is this done automatically when clicking the Install ROM From SD Card button? If not, when is it okay to flash a ROM without clearing caches?

Flashing Radios:

Same questions as those pertaining to Kernals.

As you can see I am trying to understand all these components since I don't want to mess up my phone. I'm new to Android and don't want do anything without first knowing how to undo a potential mess. Thank you all in advance for all of your feed back. These forums have given me a great deal of confidence and now I'm ready to take another step forward or into the abyss

 

[digitalslacker]

Kernal flashing:

1. When you flash a new ROM via ROM Manager, is a new kernal also installed? If so, is the new kernal uninstalled when you go into flash back to the original stock ROM?

2. If a new kernal is not installed when flashing a ROM, or if you choose to flash a new kernal is that something which is done in ROM Manager?

3. When using ROM Manager to back up an existing ROM, is the kernal also backed up?

4. Assuming the kernal is not backed up (question #3), how to you recover the stock kernal (or any previously uninstalled kernal)?

5. When recovering a prior ROM, do you flash the ROM first, then the kernal?

ROM Manager Backup & Restore:

1. When restoring a ROM from ROM Manager, does it automatically clear the various caches (user data and davlik) before restoring? Do any caches need to be cleared prior to restoring a ROM?

2. When using ROM Manager to download (via the download ROM button), then install via the "Install ROM from SD Card" button, it flashing a new ROM as simple as clicking the button? I've seen comments about clearing caches. Is this done automatically when clicking the Install ROM From SD Card button? If not, when is it okay to flash a ROM without clearing caches?

Flashing Radios:

Same questions as those pertaining to Kernals.

As you can see I am trying to understand all these components since I don't want to mess up my phone. I'm new to Android and don't want do anything without first knowing how to undo a potential mess. Thank you all in advance for all of your feed back. These forums have given me a great deal of confidence and now I'm ready to take another step forward or into the abyss

Kernel Flashing

1) Yes, custom roms are shipping with kernels. Usually they are pretty close to stock or they use a different custom kernel. Some rom devs are also kernel devs so their ROMs include their tweaked kernels

2) A kernel is always included with a ROM

3) Yes

4) n/a

5) you simple restore the recovery file made by CWM. It'll restore both the kernel and the rom to the state it was when the backup was made.

ROM Manager Backup and restore

1) You don't need to clear anything

2) For this one let me clarify something here. ROM Manager doesn't do anything but initiate a backup/restore/install automatically in Clockwork Mod. Some don't like using ROM Manager for all this because they believe it over simplifies the process. I don't subscribe to that belief but I do think you'll do yourself a favor by learning to do all this with CWM first and once you understand how that works then use ROM Manager to save yourself some time. To your question, ROM Manager gives you 3 check boxes when you flash a rom, Backup Existing ROM (does a full backup for before flashing), Wipe Data and Cache (this wipes all the saved data associated with the existing ROM before flashing, recommended if you are going from one ROM to a different one or if the dev specifically tells you that you'll need to wipe them for a specific update), Wipe Dalvik Cache (checked by default, you should always wipe this one)
Related, i generally do a full wipe every maybe 5 releases of a ROM because it seems like i have less issues if I wipe everything occasionally.

Radios
Radios are usually separate from ROMs and kernels and typically there aren't many out there. Usually we just see leaked version of new radios that may or may not increase. Right now there is a leaked radio out that isn't in the stock GNex stuff yet. You don't need to install that but if you choose to it won't be lost when you flash a ROM unless that ROM happens to also have the radio but I'm not aware of any that do. Most devs will leave flashing that up to the individual users because it's not official software.

I do NOT believe radios get backed up but I could be wrong about that. I know there are threads out there with the old radio files if you need to restore for some reason and I also believe doing one of the full factory restores using img files will also restore the stock radio.

Last bit of advice, get familiar with CWM and not ROM Manager then at least read up on the restore process. It's going to save you much headache for when, not if, you screw something up. This phone is really really hard to complete break but that's only a little comforting when you are stuck in a bootloop or having some other issue.

Hope that helps! good luck and thanks for doing a little research before just posting, most don't and we end up answering the same questions multiple times.


Sent from my Transformer Prime TF201 using Tapatalk

 

[jpprice]

Radios are not backed up. The only way to revert back to a radio would be to flash the old radio back over the existing radio.

 

[truthhunter]

I mistakenly posted this thank you on another thread - although I am grateful to those who answered my question there as well. However, I wanted to specifically thank you both for such a detailed response to my questions. Very helpful for a noob like me. For any others trying to understand this stuff, I also saved the following links which I personally found helpful.

CWM:

What Is ClockworkMod Recovery And How To Use It On Android [Complete Guide] Its a good read on CWM. **There may be some malware on this site as I seem to get that bogus security scan popup site when this page loads sometimes***

ROM Manager:

https://market.android.com/details?i...mmanager&hl=en (This is the ROM Manager video from pocketnow.com in the Andriod Market page).

TitaniumBackup:

How To Use Titanium Backup For Android [Complete Guide]

TB - User's guide

https://market.android.com/details?i...dW1CYWNrdXAiXQ.. (This is the video pocketnow.com in the Android Market for Titanium)

MyBackupPro

https://market.android.com/details?i...ackupPro&hl=en (This is the video in Android Market page).

 

[greydarrah]

OP...I know it can be intimidating to start flashing stuff, but if you just follow the very explicit directions here: http://forums.androidcentral.com/ve...backup-restore-install-roms-galaxy-nexus.html

you should have no problems. It's not as difficult as you make it out to be in your head, especially if you were ever installing some of the OS leaks that BB is always putting out. The biggest way to avoid problems is to always do the factory reset/data wipe. It may seem like a PITA at first (setting up your home screens again), but after flashing a couple of times, you'll get fast at it. I takes me about 30 to 45 minutes to have my GN flashed and re-setup now. I recommend using ROM manager just to reboot into recovery, and do all your wiping/flashing there.

 

[jpprice]

Remember, this being a Nexus and all there is always a way back to stock if you mess something up so don't be afraid to dive in.