It is dying in SimNow on CAR with a triple fault on this code: /* Clear all MTRRs */ xorl %edx, %edx movl $fixed_mtrr_msr, %esi
clear_fixed_var_mtrr: lodsl (%esi), %eax ^^^^^^^^^^^^^^^^^^^^^^
The address is OK, somewhere in high 64KB.
Hey, it's a start!
ron