Can the 'bootloader' be downgraded to 25r?

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erad1

Senior Member
Dec 3, 2010
1,351
676
MiamiBeach
As the title states...can we flash just the bootloader from 25R onto 30O using fastboot? And if so, therefore allow for the temporary boot of a custom recovery. Until now, I've only owned/flashed Samsung devices so still learning the fastboot idioms. Any ideas or nah?
 

zephiK

Inactive Recognized Developer
Aug 23, 2009
21,656
37,705
New York, NY
Why are you wanting to downgrade a bootloader to 25R? There aren't any restrictions.
If you want to temporarily boot a recovery, then just type what nneves said.

Theres no need to downgrade your bootloader.
 

erad1

Senior Member
Dec 3, 2010
1,351
676
MiamiBeach
Since the firmware has been updated to 30O, this cannot be done. I used the 'boot recovery' method while on 25R, but for some reason (security?) they have blocked that exploit, hence the question at hand.

I had even tried this method I found in a Nexus forum:

Here's some instructions I compiled for doing useful things with your Nexus. Also includes instruction to root nexus 4 without installing a custom recovery. Basically, you save the customrecovery.zip file then fastboot boot into it (NOT install, and notice you have to type the full command specified below, not just "fastboot boot customrecovery.img") and then install using the custom recovery, install SuperSU.zip for unrooting:

1) Install all STOCK files:

./fastboot flash bootloader bootloader-XXX.img ./fastboot reboot-bootloader ./fastboot flash radio radio-XXX-XXX.img ./fastboot reboot-bootloader ./fastboot -w update image-XXX-XXX.zip ./fastboot oem unlock (to unlock bootloader)

2) If you want to keep stock recovery, fast boot BOOT into custom recovery and install SuperSu.zip: 3) Install SuperSu.zip file (to root)

./fastboot -c "lge.kcal=0|0|0|x" boot customrecovery.img


there used to be a 'fastboot boot recovery recovery.img' command, but Google removed it in 4.3, so now to simply boot into your custom recovery you can type 'fastboot -c "lge.kcal=0|0|0|x" boot customrecovery.img' instead and it'll do the same thing as the 'fastboot boot' command. Meaning it will revert to your stock recovery once you reboot. So boot into custom recovery, flash superuser (Koush or Chainfire's) and reboot. done.



It didn't work but maybe another code for our device is needed?
 
Last edited:

timothydonohue

Senior Member
Oct 2, 2007
1,583
128
Portland, Maine
there is a stock 25R ROM zip floating around here somewhere. you should just be able to flash it via recovery using twrp, if you're just wanting to go back to flat stock. let me know if you can't find it, i think i may have it somewhere.
 

treChoy

Senior Member
Aug 15, 2012
247
146
Wouldn't you need to unlock the bootloader to downgrade to 25R? I think that there would be some sort of check in the signed 25R OTA update that would prevent you from flashing it.
 
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