
<p>FI;</p>
<p>When the CPUID instruction is executed on the Pentium Pro processor (model 1), the processor returns a the SEP flag as set, but does not support the SYSENTER/SYSEXIT instructions.</p>
<h2>Operation</h2>
<pre>IF CR0.PE = 0 OR IA32_SYSENTER_CS[15:2] = 0 THEN #GP(0); FI;
RFLAGS.VM ← 0;
                                                    (* Ensures protected mode execution *)
RFLAGS.IF ← 0;
                                                    (* Mask interrupts *)
IF in IA-32e mode
    THEN
  