How to - Multi-boot Android OS' on your phone

Choosing the ROMs and installing them

Clicking the Install ZIP button will bring up three more options - ‘Install Kernel’, which allows you to upgrade or replace the kernel of the ROM installed on this slot and ‘Restore Nandroid’ where you can restore a backup of a ROM that you might have stored previously. Click on ‘Install ZIP’ and select the zip file you wish to install. You‘ll be asked if you want to wipe the system, cache and data partitions before installing. Select all three and a confirmation window will ask for permissions to proceed, which will be followed by another confirmation for the file system required for that specific ROM that you are going to install.

Installation in progress

This would either be an EXT2 or an EXT4 file system. Choose the file system as EXT4, if your ROM supports it or else EXT2 should be good enough. The Boot Manager app then starts creating the image files, mounts them and installs the specific ROM into the slot. Keep an eye on the installation (status bar), which should take around 10 minutes. Once it’s complete, you can slick on the notification and proceed to ‘Manage UI’ section of the ROM. When it’s done, click on the ‘Boot ROM’ button and your phone will now boot into the ROM 1 you just installed.

Follow the same procedure for installing other ROMS of your choice in the remaining slots. Boot Manager will also install its app in all the ROM slots, so that you can easily switch back and forth into different ROMs. If you’ve taken a backup of your apps, data and settings using Titanium backup, you can restore your data and apps into other ROMs with ease. But be careful, using Titanium Backup across different ROM types can cause problems. We recommend installing apps and setting up the ROM completely from the start, rather than restoring from Titanium backup, unless you’re well versed with the backup utility.

Booting into the ROM and troubleshooting problems

The Boot Manager utility actually creates a virtual file with the partition table information of the phone and installs the ROM, accordingly. When you switch to a particular ROM, it replaces only the boot image of the phone with the original boot image of the ROM, which then instructs the handset that the partitions are not on the phone’s internal storage, but on the SD card; creating a hard link to the partitions. You can now go ahead and setup the phone as you would do while installing a new ROM.

There might be times where you will witness a failure to boot into the ROM. Don’t panic! If this happens, all you need to do is to replace the boot.img file of the phone to its original place. To do this, remove and re-insert the battery, boot the phone into recovery mode and flash the ‘update.zip’ file located in the folder ‘/sdcard/BootManager/PhoneRom/’. This will replace the original boot.img file to the phone and you shall be back on your phone’s original ROM.

For any further issues and help, you can log on to the init2winit forums and check out the discussions and also post your queries for help.