Index: head/sys/amd64/amd64/machdep.c
===================================================================
--- head/sys/amd64/amd64/machdep.c
+++ head/sys/amd64/amd64/machdep.c
@@ -1248,15 +1248,6 @@
 	}
 
 	/*
-	 * Make hole for "AP -> long mode" bootstrap code.  The
-	 * mp_bootaddress vector is only available when the kernel
-	 * is configured to support APs and APs for the system start
-	 * in real mode mode (e.g. SMP bare metal).
-	 */
-	if (init_ops.mp_bootaddress)
-		init_ops.mp_bootaddress(physmap, &physmap_idx);
-
-	/*
 	 * Maxmem isn't the "maximum memory", it's one larger than the
 	 * highest page of the physical address space.  It should be
 	 * called something like "Maxphyspage".  We may adjust this
@@ -1293,6 +1284,15 @@
 	if (atop(physmap[physmap_idx + 1]) != Maxmem &&
 	    (boothowto & RB_VERBOSE))
 		printf("Physical memory use set to %ldK\n", Maxmem * 4);
+
+	/*
+	 * Make hole for "AP -> long mode" bootstrap code.  The
+	 * mp_bootaddress vector is only available when the kernel
+	 * is configured to support APs and APs for the system start
+	 * in real mode mode (e.g. SMP bare metal).
+	 */
+	if (init_ops.mp_bootaddress)
+		init_ops.mp_bootaddress(physmap, &physmap_idx);
 
 	/* call pmap initialization to make new kernel address space */
 	pmap_bootstrap(&first);
Index: head/sys/amd64/amd64/mp_machdep.c
===================================================================
--- head/sys/amd64/amd64/mp_machdep.c
+++ head/sys/amd64/amd64/mp_machdep.c
@@ -113,12 +113,16 @@
 	allocated = false;
 	for (i = *physmap_idx; i <= *physmap_idx; i -= 2) {
 		/*
-		 * Find a memory region big enough below the 4GB boundary to
-		 * store the initial page tables. Note that it needs to be
-		 * aligned to a page boundary.
+		 * Find a memory region big enough below the 4GB
+		 * boundary to store the initial page tables.  Region
+		 * must be mapped by the direct map.
+		 *
+		 * Note that it needs to be aligned to a page
+		 * boundary.
 		 */
-		if (physmap[i] >= GiB(4) ||
-		    (physmap[i + 1] - round_page(physmap[i])) < (PAGE_SIZE * 3))
+		if (physmap[i] >= GiB(4) || physmap[i + 1] -
+		    round_page(physmap[i]) < PAGE_SIZE * 3 ||
+		    physmap[i + 1] > Maxmem)
 			continue;
 
 		allocated = true;