So, after much back-and-forth, it’s finally done. ViperOneM8 has a custom Marshmallow base now. A marshmallow snake is about to bite!
Go check out the download page. ViperOneM8_5.0.0 (anything before 5.0.0 is not Marshmallow!) is what you are looking for.
- 6.xx based firmware recommended. 6.12.1540.4 US Developer Edition and 6.14.707.1 Asia-TW (no direct RUU link but you could run this and then get official OTA). If you want these firmwares, your phone needs to be GSM, S-OFF.
- 4.xx Lollipop-firmwares (for example 4.16.401.13) apparently work too, according to Artur’s tests – however, we have had quite a few issues with older firmwares on the M9 and it will be a very good idea if you actually do the update on the M8 too, just to avoid potential problems. We were not able to observe long-term effects (wakelocks, drain, etc) yet, so, better safe than sorry.
- No carrier support. We might be adding Sprint, VZW, TMUS, ATT once they receive their own Marshmallow updates. Until then, please have patience, my young padawans! Trying to flash the ROM on those can lead to a device unable to boot further than bootloader or recovery!
- Firmware: most GSM phones can try to work with HTC’s Developer Edition firmware. It works well for most international users too. This requires S-OFF first. CDMA (Sprint and Verizon in the US) can absolutely NOT flash the Developer Edition firmware, not even with S-OFF! This would possibly break your phone so you have to send it in! Be warned!
- Had to re-word a few things to try and make things clearer.