[HTC One SV] Modding.MyMind:
This is currently built with the K2 variant devices kept in mind. I will not guarantee anyone else who does not own a K2 variant that this will work. If you do not own a K2 variant and this does work, please, comment on this thread to let myself and other viewers know. Please specify your device and Rom. However, if you read my first post and everything you saw is fitting to your device and roms, then it is VERY LIKELY that this WILL work for you - Thanks.

To automatically generate your boot.img and/or rom zip to be 'dual bootable' you must download the DualBoot_v1.0 zip at the end of this post and extract it to the root of your internal sdcard. This will save you the hassle of manually unpacking, editing, and repacking the boot.img and as well as extracting, editing, and pushing back the updater-script originally from your rom zip. This process is really fast at accomplishing its goals while doing all the work for you ;).

The ZipEditor.sh will use my three binaries to edit your boot.img and while doing so, it will create a temporary repack.sh file to allow it to be properly rebuilt again. It will also create a backup of your original boot.img which will be named boot1.img. The dual boot.img will be named boot2.img.

This script is literally built around my three executable binaries - unmkbootimg, mkbootfs, and mkbootimg.

Of course, in order to use the scripts, you need to have had partitioned your SD card the way I described in the first post.

Initial Setup

First of all download the zip at the end of this post, unzip it and copy the DualBoot folder to the root of your SD card.

Install Script Manager from Play Store

How to use

A. ZipEditor.sh

Download the ROM you want to install and copy the zip into /sdcard/DualBoot/OriginalZIPs

Also download a suitable GAPPS.zip and copy it to the same directory (if this applies to you)

If you need to convert additional zips, the tool is designed to process as many as it finds in this directory

Open Script Manager, browse to /sdcard/DualBoot and tap on ZipEditor.sh

In the next screen, select the first two icons on top (Favorite and SU) and then select, Run.

The tool will give you some info about your device. Check them and if they are not right, then kill the script. If they are correct, press Enter to continue. The Editor will process the zips one by one. Everytime a zip is completed, it will prompt you to press Enter.

When all zips are processed you may reboot to recovery, make a backup of your current ROM and flash them.

When you reboot, your secondary ROM will load.

B. SwitchROM.sh

The name is self-explanatory. This tool can only function if it finds the files boot1.img and boot2.img inside the /sdcard/DualBoot/img folder.

These files will be automatically generated when you convert a ROM zip in the ZipEditor. Alternatively, if you know what you are doing, you can create and put them there yourself.

Tap it in Script Manager and again select the first two icons (Favorite and SU) and Run. It will automatically detect the current ROM, flash the boot.img of the other one and prompt you to reboot. Use your Power-Menu and reboot your device. Your device will now boot to the other ROM.

Credits for the ZipEditor.sh and SwitchROM.sh goes to [MENTION=2863096]dreccon[/MENTION]

Credits for the executable binaries goes to [MENTION=5537766]Modding.MyMind[/MENTION] - That's me :)