What is a boot loader?
When you press the power button on your mobile device power is sent to a part of the flash memory that initiates the boot loader. The Boot loader
is device specific and knows about the hardware in your phone. It will start a steady state in your device and once it is initialised the phone will start to execute the Kernel or boot into a Recovery Kernel. Once the Kernel is booted the ROM is loaded.
If you cannot unlock your boot loader then a device manufacturer specific Kernel will be loaded. Once loaded you could still run a custom ROM but will have limited control. In some cases the boot loader code can bereplaced
However, once you unlock the boot loader
you will have some support issues and if you bought a phone from some spiteful vendors it will simply be bricked using the eFuse method.
Bricked means just what it says. You can use it as a brick. It will not work and may never work again. The best advice is to simply walk away from manufacturers
that do that.
I have a Sony Xperia ZL so this is what I need to do.
Sony does not allow you to replace your Bootloader but you can request a key to unlock your Bootloader. You have to electronically sign away your guaranteed warranty rights but you can still get warranty repairs if YOU did not mess up!
Here are the manual steps.
Dial *#06# and note down the IMEI code
Dial *#*#7378423#*#* and navigate to Service info > Configuration > Rooting Status
Is Bootloader Unlock Allowed? If not - bummer. Really.
Install the magic software. Please donate some funds as this is very very very cool software.
I have used this on windoze 7 and the version I am using for this blog page is running on Linux Mint 16. Cool!
Plug your Sony into a USB port. Ensure your developer option is active (Click on about phone 5 times) and USB debugging is set.
Start flashboot (My phone is currently rooted but I am resetting it while writing this blog post)
Notice the BLU is selectable. Click on it. You will now need to shutdown the mobile.
Leave your USB cable into the computer and pull the other end out of the mobile. Hold volume up button and plug in USB cable in mobile’s port.
Click on BLU and fill in the details. Simples.
Notice the Relock option? Yes, you need to do this BEFORE sending it in for a warranty repair.
Some of the Sony phones supported by Flashtool:
XPERIA Z1 COMPACT (D5503)
XPERIA Z1 (C6902,6903,C6906,C6916,C6943)
XPERIA Z ULTRA (6833)
XPERIA TABLET Z (SGP311,SGP321)
XPERIA ZR (C5502,C5503)
XPERIA SP (C5302,C5303,C5306)
XPERIA Z (C6602,C6603,C6606)
XPERIA ZL (C6502,C6503,C6506)
XPERIA TX (LT29I)
XPERIA T (LT30P)
XPERIA V (LT25I)
XPERIA S (LT26I)
XPERIA ARC S (LT18I)
XPERIA PLAY (R800I|X)
XPERIA U (ST25I)
SONYERICSSON XPERIA ARC (LT15I)
SONYERICSSON XPERIA NEO V (MT11I)
SONYERICSSON XPERIA NEO (MT15I)
SONYERICSSON XPERIA NEO L (MT25I)
SONYERICSSON XPERIA MINI PRO (SK17I)
SONYERICSSON XPERIA MINI (ST15I)
SONYERICSSON XPERIA ACTIVE (ST17I)
SONYERICSSON XPERIA RAY (ST18I)
SONYERICSSON XPERIA LIVE WALKMAN (WT19I)
SONYERICSSON XPERIA X10 (X10I)