Reverting from Modded firmware to stock firmware

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Hi there,

Sorry if this thread is redundant, but it seems the topic is always buried within other threads versus focusing on it. Then again, maybe it's a simple answer and needs no focus.

I had some quick questions before I mod my G1, and know it has been touched upon, but just want to make sure.

Once your phone is modded and using the test keys, then is it currently impossible to ever go back to an official firmware update without the need to resign it with the test keys?

I guess I am curious if Google ever did force a 'test key' OTA update that took away root (or worse), then would we be stuck at that version until someone finds a way to flash the device via other means? Even if we had root, would we ever be able to revert back without having Googles private key?

Also, with the new modded firmware will we be able to install older revisions (i.e. go back to an earlier modded release candidate? say RC32 to RC30)

Thanks,
olsk00lz

If you're that worried about Google signing an update with the test keys (which, FYI, would be a horrible idea, as the devices that have the official keys would freak and couldn't update), then do this:

Make your own keys (it's not too hard, I'm sure JesusFreke could help), sign the modded RC30 yourself, and update to that. There's nothing Google could really do to stop that, except somehow make an update that didn't require signing. If they did that, we could just make our own update that didn't need signing, which wouldn't even require root access anymore.

Makes sense, but questions still remain. More out of curiosity.

- If you wanted to sell your phone as stock or something later and wanted to revert back to "enable OTA"... is there anyway to do this?
* May not be possible without a private key???

- If you are using the test keys, or your own keys, then can you install any firmware. a) revert from a modded RC32 to a modded RC30 with google test key, or b) switch from a modded RC30 (goog test key) to a modded RC30 (your own key)
* Should be possible if you have both public/private keys??

Also, anyone see an impact with the new fingerprint being sent back to google, I have seen suggestions to create a new entry in your host file to prevent this.

Thanks !
oldsk00lz

Yes, you can go back to stock updates.
You can grab the recovery image from one of the official updates and flash it in the same way you did to get the modded one, and then apply the official update.

Originally Posted by oldsk00lz

Makes sense, but questions still remain. More out of curiosity.

- If you wanted to sell your phone as stock or something later and wanted to revert back to "enable OTA"... is there anyway to do this?
* May not be possible without a private key???

- If you are using the test keys, or your own keys, then can you install any firmware. a) revert from a modded RC32 to a modded RC30 with google test key, or b) switch from a modded RC30 (goog test key) to a modded RC30 (your own key)
* Should be possible if you have both public/private keys??

Also, anyone see an impact with the new fingerprint being sent back to google, I have seen suggestions to create a new entry in your host file to prevent this.

Thanks !
oldsk00lz

Yes, you would be able to reflash the official keys, so that it'll OTA update again. You should have backed up your keys before you flashed (I'm not sure if the guide on the forums tells you to do this, it probably doesn't, so you shouldn't follow that exactly).

You probably won't be able to go from modded RC30 to official RC30. The updater would probably disallow it because it is the same version. I think you'd have to modify the modded to RC29 (although, there's probably a build number that it uses somewhere, I doubt they use the RC identifier we do for update checking).

If you were to resell the G1, just reflash the normal keys. When the next update comes out, he'll be back on stock.

Gotchya.... Thanks!

I think your question has already been pretty much answered, but let me clarify the details

There are 2 ways you could apply an "official" update over a modified one:
- You can resign the official update with the keys used by the modified recovery image.
- You can re-flash one of the official recovery images, and then apply the official update without having to re-sign it. The updates themselves contain the recovery image for that version (look for recovery.img). So you could extract that file, flash it onto the recovery partition, and then apply the update.

hey J.F. correct me if im wrong...

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But you included the goog signed recovery.img in the androidmod.zip so you could just refollow the directions in the package to go back to a goog signed G1.

At least that's how I understood it.


Bhang

Your missing out on something important here.. when most of the population will have been upgraded to a non rootable firmware your rooted g1 will be worth n time its original value. Why on earth would you sell it locked for 1/2 of the original price???!!!

Originally Posted by bhang

But you included the goog signed recovery.img in the androidmod.zip so you could just refollow the directions in the package to go back to a goog signed G1.

At least that's how I understood it.


Bhang

No, I included the RC29 boot image (not the recovery image), which was just a convenient "known good" boot image I had laying around at the time when I packaged it up.

You'll need to get an official recovery image from one of the official updates. It's called recovery.img, and is in the system folder in the zip file.