trap 12 during boot

[Matthew Dillon]

:The trace does not help here:
:db> trace

    You can experiment a bit by tracing higher addresses starting at the
    stack pointer.  So, for example:

:fault virtual address   = 0x8758b53
:fault code              = supervisor read, page not present
:instruction pointer     = 0x8:0xc02f0a50
:stack pointer           = 0x10:0xc048eac8
:frame pointer           = 0x10:0xc048eacc
:..

    Try:

    trace 0xc048eacc
    trace 0xc048ead0
    trace 0xc048ead4
    trace 0xc048ead8
    trace 0xc048eadc
    trace 0xc048eae0
    ...
    until you get a good trace (or the machine locks up from the debugger
    trapping into itself too many times).

    If that doesn't work boot a backup kernel and generate a nm output on
    the kernel binary that panics so we can figure out which procedure it
    crashed in.

						-Matt