tells me "You need to restart your computer"

HI - after a software update, it needed to restart, and now, it will not come on all the way. It comes on and tells me "You need to restart your computer" with the following on the screen:

Panic(cpu 0 caller 0xffffff800064ba7b): “Unable to find dirver for this platform: \”ACPA\”. \n”\n”@/SourceCache/xnu/xnu-1699.26.8/iokit/Kernel/IOPlatformExpert.cpp:1504

Debugger called: <panic>

Bactrace (CPU 0_. Frame : Return Address

0xffffff807978bdd0 “ 0xffffff8000220792

0xffffff807978be50 : 0xFFFFFF800064ba7b

0xffffff807978be60 : 0xffffff800062937d

0xffffff807978beb0 : 0xffffff8000629bae

0xffffff807978bf30 : 0Xffffff8000629f29

0xfffff807978bf70 : 0xffffff8000628b0f

0xffffff807978bfb0 : 0xffffff8000820057

can’t perform kext scan: no kext summary

BSD process name corresponding to current thread: Unknown

Mac OS version:

Not yet set

Kernel version:

Darwin kernel Version 11.4.0: Mon Apr 9 19:32:15 PDT 2012; root:xnu-1699.26.8~1/RELEASE_X86_64

Kernel UUID: A8ED611D-FB0F-3729-8392-E7A32C5E7D74

System uptime in nanoseconds: 360613079