[Miscellaneous Android Development] cappa72:
Repartition information

Dear Owners,

Here is the repartition possibility for the Lenovo A850+ MT6592.

Before you do

any

chages, you have to know:

This is not for noobs, even if the packages were tested.

I do not take responsibility for any damage that can be caused!

In the case of the potential clones (A850s, A850c, A850p and who knows what fakes there are), this method may cause permanent damage!

Background.

The Lenovo A850 + MT6592 telephone’s ROM is approx. 4GB. This is the total internal storage, which is mentioned so that "4GB ROM"

What does it really mean for us?

The whole eMMC contains many partitions and other ROM-parts – including boot records, recovery, nvram, etc...

What is important is that we’ve got 2,1GB storage for installing appication (it is the internal storage menuitem in the settings --> storage).

Well, after the introduction of the change.

In stock partition table the system partition is 1,2GB, which is not really necessary.

Why?

The Lenovo ROMs usually need approx 800MB of storage, the other 400MB are free. And the uses do not use that. If this free space is added to the data partition, the storage for installing the applications can be extended to 2,5GB.

This modification does not affect the system stability.

The AOSP rom (this thread) does not need more than 450MB. For this reason the data partition can be enlarged – in extreme case - up to 3GB; in the same time the system partition is reduced to 450MB.

The following steps you need to do:

1, If you have not got a complete system backup, then a do it first.

You can do it with MTKDroidTools (by rua1) or SP Flashtool readback, or use dd command.

Without making a complete backup the modification of the phone is a suicidal action...

2, CWM recovery on your phone

It is very important that the following be CWM recovery on your phone!

CWM Recovery 6.0.1.2 by Cappa72 - this is a ported recovery,

where the product description fits the phone. There may be other recoveries from some source, in which you can find inappropriate product description. In this case the modification scripst will be stopped.

If you do not know how you can install CWM, you need to think whether you need these modifications either.

Important that PhilZ recovery will not work well for this repartition!

3, Download Packages

CWM

Repartition script 2.6GB

Repartition script to 2.8GB – only for AOSP ROM!

Repartition script to 2,94GB - only for AOSP ROM!

Restore to factory partition

The zip packages must not be decompressed!

These have to be downloaded and then copied onto your physical SD card – I would recommend the root directory of the SD card.

Considering that the A850+ has not got real internal SD card, usethe physical SD card during the change!

4, Applying the changes

4.1 Do a CWM backup as a minimum.

It is really necessary to do it first because this is the basic backup, from which you will be able to restore the system.

If you do not do it, you can loose your system, and your phone will not be able to start.

Skipping save is approx. equals suicide (phone-killing).

4.2 Enlarge data partition to 2.6GB

Install the Lenovo-A850+_data-repart-to-2.6GB_v1.zip from CWM.

Login to CWM

Install zip from SD card -> choose zip from sdcard -> browse to the

Lenovo-A850+_data-repart-to-2.6GB_v1.zip file and -> (among many NO) YES.

This rewrite the partition table in seconds.

Go back to the main menu of CWM back button or the ++++ Go back ++++ menu.

Now, you need to reboot the recovery.

Advanced -> reboot recovery

After the recovery restart, there are error messages on the scree.

Do not worry about that, it is normal (the recovery wants to access the partitions, but it does not find them)

Next step is the format actions.

We need to format the following 3 partitions:

system

cache

data

The system can be formatted in the CWM.

mount and storage -> format system -> YES

mount and storage -> format cache -> YES

mount and storage -> format data -> YES

(The cache and the data can be formatted also by wipe data/factory reset menuitem in the main menu of the CWM)

Here, the repartition has been done, BUT!

Considering that the system was formatted, a simple reboot is not en‪ough: there will be nothing on your phone.

You need to restore your CWM backup that you saved right before the modification.

Use Backup and Restore -> Restore -> Select the right date -> YES

After restoring your backup, you can safely reboot your phone.

If it boots, then you worked well.

Enjoy!

4.3 Restore the partitions to stock

You need the Lenovo-A850+_data-repart-to-STOCK_v1.zip file and you need to install it via CWM.

See 4.2 instructions.

4.4 Enlarge data partition to 2.87GB

Lenovo-A850+_data-repart-to-2.8GB_v1.zip file and you need to install it via CWM.

See 4.2 instructions.

4.5 Enlarge data partition to 2.94GB

Warning! This is only for Vanilla AOSP, if the system partition does not exceed the limit of 450MBytes (471859200 bytes). You have to check it with root explorer, or your favourite explorer.

You need the Lenovo-A850+_sys450-data2.9GB_v1.zip file and you need to install it via CWM.

See 4.2 instructions.

Be careful and good luck!

If you are stucked in any point of the modification, ask in this thread. Do not send me private messages. The forum has got its own power: many people read it and you do not need to wait for one person. It is a community.

Other small tricks will be coming soon...

-------------------------

Credits:

bgcngm, who compiled the base of the CWM 6.0.1.2 recovery

bgcngm, who prepared the mtktools

ebr1 modification by cappa72

Thanks to tirta.agung who explained the background of the boot record files.