What is npvhash=4095 ??? iMac won't go to login screen

I go to my computer to turn it on and first there is the usual white start up screen but with no Apple logo and them a black screen appears with a bunch of code on it. The first line is npvhash=4095 and all this other code but everything I try, I cannot get to the login screen. I have tried turning it off and on but that is no good. Since I have a Bluetooth keyboard I can not enter safe boot or anything that you would press at the start up screen. Would a keyboard that connects with USB work then? Has anyone ever had this problem?