Being an LG Optimus One owner, I was always looking to have CyanogenMod on my phone. Though LG confirmed Gingerbread for Optimus One, there is still no sign of it. There was a post on LG Facebook page that Gingerbread update will be rolled out by end of may for Optimus One, but still no news about it. This guide will give all the steps needed to flash CM7 to your Optimus One from rooting your phone till getting CM7 up and running!
Step 1: Root your device
Rooting your device gives you super user access to your device which is needed in next step. Without rooting your device you can’t perform any of the next steps. To root your device, first check your firmware version by going to “Settings->About Phone”. If your firmware version is v10b, install z4root & click on “Permanent Root”, your device will be rooted & restarted. If your firmware version is higher than v10B (v10c, v10d, v10e or v10f) then install Gingerbreak & root your device. Though Gingerbreak is mainly for Gingerbread (2.3) it also works for Froyo (2.2). Make sure that you have ‘USB Debugging” (Settings->Applications->Development) enabled in both the procedures. Once your phone is rooted, you can see “Superuser” app installed in your applications.
Step 2: Download and setup Android SDK with ADB
In our next step we will be running few commands. If you are comfortable typing these lengthy commands through a terminal app on your phone, you can skip this step. I prefer ADB since I can easily copy paste long commands without making any mistake. Download Android SDk from official website, if you are on Windows, you can download .exe & install. If you are on Linux or Mac, download the zip package & extract it to a folder. Unlike before, ADB is not bundles with SDK & needs to be installed separately. Run your-sdk-path/tools/android & you will see a pop up with which you can install additional tools to your SDK. Select “Platform-Tools” & install it. Once the installation is complete, you can see a new folder ‘Platform-Tools” inside your SDK folder. Run platform-tools/adb start-server to start ADB server & platform-tools/adb shell to get into ADB shell from your command prompt or terminal.
Step 3: Install Custom Recovery
Custom recovery helps you take complete backup of current ROM & lets you flash new ROMs easily. You may follow steps mentioned in this forum post to install custom recovery. To enter commands specified in that post you need to get into ADB shell with root access. To do that run ‘sdk-path/platform-tools/adb shell’ with your phone connected. You will see ADB shell with “$” symbol waiting for additional commands. To gain root access, make sure you have phone in unlocked state & enter “su” in your ADB shell. You will see a prompt on your phone screen asking you to grant root access, click “Allow”. Now you ADB shell’s “$” symbol should turn to “#” symbol confirming you have gained root access. Follow the steps according to the forum post.
Step 4: Flashing CyanogenMod
CyanogenMod is not officially supported on LG Optimus One. But, @mik_os has done a great job porting it to LG Optimus One. You can download his ROM from here. Place downloaded ZIP package in the root of your SD card & restart the phone. You need to enter into recovery after reboot, to do that hold down Home, Vol Down & Power keys simultaneously when you see the LG logo. Now you will see Amon Ra recovery screen if you are successful in previous steps. Before we proceed with flashing CM7, lets take a backup of your current ROM just in case if you want to come back to it! Select “Backup/Restore -> Nand Backup” to do a nandroid backup of your current rom. Use Vol Up to move up, Vol Dn to move down, options key to select & return key to go back to previous screen in Recovery menu. After backup, goto “Wipe” & wipe cache & dalvik cache. Now goto “Flash ZIP from SD card”, select CyanogenMod zip file you previously downloaded & pasted into root f SD card & confirm flashing.
Once flashing is done, reboot the phone & enjoy CM7 on your LG Optimus One!!
Disclaimer: The guide written above is what I followed to get CM7 on my phone & best to my knowledge. I will not be responsible if you end up bricking your phone. Follow the guide at your own risk.