Nokia Lumia 900If you own an older Lumia, one currently running Windows Phone 7.5, take it out of your pocket, listen up, and prepare yourself. A new firmware build of Windows Phone 7.8 has popped up at NaviFirm for a number of older Lumia devices, including the 510, 610, 710, 800, and 900. An update is coming.

Mentions of older Lumia devices have popped up in Nokia’s servers before, but this is the most comprehensive list we’ve seen yet. Since everything seems to be shaping up behind-the-scenes, and because we’ve heard multiple rumors about the arrival of Windows Phone 7.8, a roll out seems imminent—hopefully just a few weeks away.

You can download the firmware for your respective device now, NokiaPowerUser said, but there’s always an inherent risk involved when installing a (possible) incomplete build of software.