Installing a Custom ROM + Kernel on an Android Phone - LGP500

This post is in the 4rd and the last part of the series - How to Root and install a custom ROM on an Android phone.

First part - http://blog.darshshah.org/2012/06/rooting-my-android-phone-lg-optimus-one.html

Second part - http://blog.darshshah.org/2012/07/custom-recovery-and-nandroid-backup-for.html

Third part - http://blog.darshshah.org/2012/08/flashing-new-baseband-on-lg-p500.html


[Note: Do it at your own risk. I will not be responsible if your data gets lost or your phone bricks.]

So, in this part, I am going to explain on how to flash a custom ROM and Kernel on the android phone. First, what is custom ROM. When you buy a smartphone, there is a default OS installed in it. In our case, a certain version of Android (either Gingerbread or IceCream Sandwich) is installed. The handset companies mostly do customization in the look and feel of OS for having a distinguishing product in the market. For example, many Samsung phones have a TouchWiz UI installed on it. Likewise, HTC phones have HTC Sense and my LG P500 came with some pre-installed apps.

Cyanogenmod 9 animation screen

What if you don't want to use the default UI of your phone? What if your phone doesn't allow you to install customized themes ?  What if you wanted to upgrade to a higher version of Android like JellyBean even if your OEM doesn't support it ? What if you want some awesome optimizations on the phone. The answer for all the above is to install a custom ROM !

Custom ROM are just like normal android OS but may have some optional features. The basic utility of phone functioning is same in all the ROMs but the UI and other optimizations differ. So for example, there is a cool UI focused ROM called MIUI. A battery saver ROM is also available called Oxygen ROM. So, basically there are hundred's of customized ROMs out there and it depends upon you which you want to use. A more complete list can be found here.

I personally used  Cyanogenmod for my phone. For more info - http://www.cyanogenmod.com/. The reason for choosing this ROM is because it is quite stable with all features working and has an active community for support.

Along with ROM, there is something called 'kernel'. Kernel is essentially the linux kernel. Mainly used for booting and for hardware-software interaction. The use of kernel is for overclocking (not advised !) for your phone, making your phone faster and many more things. The important thing to take care is that you need to check the compatibility of kernel with ROM. If you are flashing a kernel then take care when you flash the ROM. Also, ROMs have kernels. So, just flash the ROM and you are done.

So, now I will explain the process on how to actually do it.

1. Download the ROM/Kernel (zip versions) which you want to install and place it in your SD card.  Use signed version if it is available. Also download gapps if it is provided along with the ROM.

2. Reboot your phone and go into Recovery mode. I am using AnomRa recovery tool as described in part 2 of this series. So, the options screen are seen as shown in the image.

3. Go to Wipe and do - Wipe cache, Wipe Dalvik Cache and Wipe ALL data/factory reset. If flashing just a new kernel, don't do Wipe ALL data/factory reset as your current settings will go away. ( Remember to take a Nandroid backup before you do wipe. If not, see part 2 for it.)



4. Go back to the main menu using the back button and click on Flash zip menu.

5. Select Choose zip from sdcard. (image below)

6. Select the zip file of the custom ROM?kernel and the process will start. If 'verification error' comes, go back and do - 'Toggle signature verification'.

7. If you flashed a custom ROM, then reboot the phone via using the first option in main menu. Once rebooted,  flash the gapps via using the step 4-5 and selecting the gapps zip file.

Reboot and you can see the newly installed custom ROM !

Finally, this link may help you to get some clarity - http://forum.xda-developers.com/showthread.php?p=15309588#post15309588. Happy Flashing :)

Hope this 4 part series was helpful to you. I was also initially afraid to root my phone and do all this stuff but once I understood the process and its essence, I did it at once. So, I hope you will also do the same if you haven't done it so far ! Get the CONTROL back in your hands !!