Sunshine is one of those Swiss Army knives of the Android world that enables a range of tinkering options for popular devices, and with its latest update to version 3.1, support has been added for the HTC One (M9). Not only can it perform a range of actions on the One M9, but it can also now remove SIM locks on the majority of HTC manufactured handsets.
Sunshine allows One M9 owners to achieve S-OFF (needed for making lower-level modifications to the device), but it isn’t quite as automated as it is for other handsets; One M9 owners will need to visit HTCDev Unlock to unlock their bootloader, and will need to use a custom recovery and root tool (such as Chainfire’s Super SU) to achieve root. However, in combination with these tools, you’ve got the keys to the castle, so to speak.
The SIM unlock supports a wide variety of HTC handsets, but you can’t SIM unlock the One M9 just yet, though there probably aren’t too many of these being sold SIM locked in Australia I wouldn’t think.
If you want to start modding your HTC One (M9), the best bet is to head to the developer’s website at theroot.ninja and grab the latest version of Sunshine ready to go. The tool will run a number of tests to ensure compatibility, and will give instructions to guide you through various processes. Sunshine isn’t exactly free though, charging users $25 to unlock and/or achieve S-OFF.
For further information, check the Sunshine FAQ, and there’s an ongoing support thread at XDA.
I used it on my M8 and it worked well at the time. Unlocking the bootloader, rooting, flashing TWRP, using Sunshine, changing the CID and MID, and flashing the firmware, all via the command line, is a painful process for HTC handsets. Much easier on LG and Sony devices.