Since we don't use PG_NX yet, don't turn on EFER_NXE quite yet. This needs

to be done based on the cpuid bits.  AMD says that we should test the cpuid
features bits for certain things, such as this.

sys/amd64/amd64/machdep.c

@@ -1104,9 +1104,11 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 #error "have you forgotten the isa device?";
 #endif
 
+#if 0	/* Not till we test the features bit */
 	/* Turn on PTE NX (no execute) bit */
 	msr = rdmsr(MSR_EFER) | EFER_NXE;
 	wrmsr(MSR_EFER, msr);
+#endif
 
 	proc0.p_uarea = (struct user *)(physfree + KERNBASE);
 	bzero(proc0.p_uarea, UAREA_PAGES * PAGE_SIZE);

sys/amd64/amd64/mpboot.S

@@ -102,7 +102,11 @@ protmode:
 	 */
 	movl	$MSR_EFER, %ecx
 	rdmsr
+#if 0	/* not till we test the NX cpuid bits */
 	orl	$EFER_LME | EFER_SCE | EFER_NXE, %eax
+#else
+	orl	$EFER_LME | EFER_SCE, %eax
+#endif
 	wrmsr
 
 	/*