[Xperia Z4 Tablet General] najoor:
I wanted to share two things with you guys here in Tablet z forum:

1- First of all, [MENTION=3975929]zxz0O0[/MENTION] has developed a code based on the CVE-2015-1805 vulnerability that gives temporary root access to a select range of devices (including Tablet Z4). Let me try to explain in my words what that means. A full blown root gives permanent read/write access to /system and /data partitions. On an unrooted Tablet Z4 you only have read access to /system and no access to /data. With this root, you will be able to have a temporary terminal or adb session that gives you read access to /system and read/write access to /data. Why not write access to /system? Because Sony runs a service called RIC on Xperia devices that makes it impossible to mount /system as writable. In the past this would be patched by modifying the system partition. But in the recent Kernels sony has implemented a mechanism (dm-verity) which checks /system and if it is modified the device does not boot. So even if this (or any other) root method gave you the ability to write in /system you could not use it because your device would not restart the next time you turn it off. The solution would be to patch the kernel which requires an unlocked bootloader. IF you unlock your bootloader you lose your TA partition permanently which includes some of the Xperia features and licenses that have to do with image processing and some DRM. So a lot of us do not want to unlock the bootloader.

Then what good is this new root method? Since it gives you read access to the system partitions you can use this method to back up your TA partition. The idea is that if you ever unlock your bootloader you may be able to use this TA back up to return the system to its original state if you ever decide to relock it. Another benefit is that tools like Titanium back up which require access to the /data partition can now function (in a limited sense) although someone has to work out the details of that.

To download the pack that allows backup and restore of the TA partition go to http://xdaforums.com/crossdevice-dev/sony/iovyroot-temp-root-tool-t3349597

After you create the backup, you can unlock the bootloader, and use your TA backup and the procedure outlined here: http://xdaforums.com/xperia-z5/development/root-automatic-repack-stock-kernel-dm-t3301605 to create a csutom kernel that uses all the good stuff in the TA backup and emulates an environment where your tablet behaves like one with an unlocked bootloader. The camera denoising algorithm and all other Sony proprietary software which would be disabled after unlocking the bootloader should work.

If you want to return the tablet to its unlocked condition you will need this TA backup. Some explanation about retrieving the TA partition from this backup, if you unlock the bootloader and decide to relock it, is given here http://xdaforums.com/showpost.php?p=66142823&postcount=16 and methods to do so are outlined at: http://xdaforums.com/showpost.php?p=66158970&postcount=68

Note that to use this root you need to downgrade to lollipop (preferably version 28.0.A.8.260)

I have explained procedures to use the above tools here http://xdaforums.com/z4-tablet/general/guide-safe-bootloader-unlock-restore-t3362391 at length.

2- Now, here is the use I have found for this temporary root: I was always bothered by the fact that not only I could not (easily) get the 17 hour advertised on-screen use out of my tablet, the standby power consumption was always too much. Whereas I could optimize my other (rooted) devices to only drain 1-2% a day in standby, tablet Z4 seems to settle for nothing less that 5-10% a day in standby. This is what you can do to get excellent standby power from your tablet:

A) Say goodbye to your google apps (with the exception of Chrome and Maps) and other marginally advantageous apps. They wake your device up all the time when it is supposed be sleeping and endlessly chat with google servers even if you turn all the communications off in the google settings. So disable all of the apps listed in the attached pictures , plus lifelog,via settings. Don't complain about not being able to use the gmail or youtube apps. Other great replacements exist. Leave "Google App" active if you use the voice search or voice typing feature. Also uninstall the pre-loaded apps that you aren't using like facebook (which is cancer for any phone), Lifelog, Privilege, spotify, etc.

B) In settings under wifi open the advance menu turn off both "network notification" and "scanning always available", and change "keep wifi on" to "only when plugged in"

C) Under "power management" in settings, activate stamina mode and extended standby (no need to activate extended usage).

D) Finally (and here is where the temp root becomes useful) extract the file "iovyroot" from the file in the above link and put it in your adb directory. Open a command terminal and type:

adb push root\iovyroot /data/local/tmp/iovyroot
adb shell chmod 777 /data/local/tmp/iovyroot
adb shell

This gives you an android terminal shell. Continue with the following:

/data/local/tmp/iovyroot
pm disable com.sonyericsson.idd.agent
pm disable com.sonymobile.entrance
pm disable com.sonyericsson.updatecenter
pm disable com.sonymobile.anondata
pm disable com.dsi.ant.server
pm disable com.sonymobile.gmailreaderservice
pm disable com.sonymobile.googleanalyticsproxy
pm disable com.sonymobile.mx.android
pm disable com.sonymobile.enterprise.service
pm disable com.sonymobile.synchub
pm disable com.sonymobile.phoneusage

That is it. You just disabled the update service and a bunch of other things and extended your standby battery life. These settings will survive a reboot.

Let me know how it works out for you. If you find other creative uses for this temp root share here.