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(Chris Devlin) #1

Revert to KitKat on your


Nexus 7


Not enjoying Lollipoponyour
Nexus 7? You can go b

W


hile Android KitKat is the newest release
of the operating system, not all apps
work on it today. On older dev ices, such as
the 2012 Nexus 7, some users are reporting a
noticeable drop in performance. In addition, some
ver y nice hacks such as the incredibly versatile
Xposed framework are currently not compatible.

Updating to Lollipop isn’t irreversi
you can fl ash back to KitKat, but
unfortunately you will have to wip
your phone or tablet in the process
can then choose whether you want
update again manually at a later da
when the system is more mature.

While ROM version upgrades are designe
to be completed without wiping your data, the
same doesn’t apply when going back the other
way – changes in database formats can lead to
crashes when you roll back to an older release.
For this reason, you will need to wipe your data
via the fl ash script.

Prepare to wipe your data
2

After you’ve rolled back to the older
Android release, your device will still try and update
to the current version. Obviously you want to stop
this happening or you’ve wasted your time! You
can do this manually or you can rename ‘/system/
etc/security/otacerts.zip’.

Prevent OTA updates
4

As Nexus devices are primarily intended to be
developer tools, it’s useful to be able to fl ash back
to old software versions for compatibility testing
reasons. Google makes this possible via the factory
images. Exactly how far you can go back in time will
depend how old your device is!

Download a factory
image from old versions

1


Flash the image
As we are wiping, the flash script can be
used in its entirety. Extract the tar.gz file and you
will find a flash-all script that you need to run from
the command line, with the device in bootloader
mode. Enter bootloader using your device’s key
combinationoratoolsuchasQuickBoot.

(^3) If you do accidentally apply an over the air
update, don’t be tempted to interrupt the fl ash
process. If you stop the update at a critical time,
you could end up bricking your device. If the device
doesn’t autoreboot, you may be able to fl ash the
old images again.
lly applying OTA
5

Free download pdf