diff --git a/kern/arch/x86/apic.h b/kern/arch/x86/apic.h
index 5752b89..8d0b959 100644
--- a/kern/arch/x86/apic.h
+++ b/kern/arch/x86/apic.h
@@ -225,7 +225,7 @@
 
 enum {
 	Nbus = 256,
-	Napic = 254,	/* xAPIC architectural limit */
+	Napic = 256,	// XXX /* xAPIC architectural limit */
 	Nrdt = 64,
 };
 
diff --git a/kern/arch/x86/entry64.S b/kern/arch/x86/entry64.S
index 9740273..c8378d8 100644
--- a/kern/arch/x86/entry64.S
+++ b/kern/arch/x86/entry64.S
@@ -265,7 +265,7 @@
 insert_pml3:
 	shrl	$7, %esi 	# want to shift vaddr >> 39
 	andl	$0x1ff, %esi
-	orl	$(PTE_P | PTE_W | PTE_G), %edi
+	orl	$(PTE_P | PTE_W), %edi
 	movl	%edi, (%ecx, %esi, 8)
 	movl	$0x0, 4(%ecx, %esi, 8)	# being clever, i know upper bits are 0
 	ret
@@ -280,7 +280,7 @@
 	shrl	$30, %edx
 	orl	%edx, %esi
 	andl	$0x1ff, %esi
-	orl	$(PTE_P | PTE_W | PTE_G), %edi
+	orl	$(PTE_P | PTE_W), %edi
 	movl	%edi, (%ecx, %esi, 8)
 	movl	$0x0, 4(%ecx, %esi, 8)	# being clever, i know upper bits are 0
 	ret
diff --git a/kern/arch/x86/ioapic.c b/kern/arch/x86/ioapic.c
index 3e0e481..b4bfb09 100644
--- a/kern/arch/x86/ioapic.c
+++ b/kern/arch/x86/ioapic.c
@@ -271,6 +271,13 @@
 	struct apic *apic;
 	static int base;
 
+	// XXX machines with multiple IOAPICs can have one outside the default
+	// area...  goddamn
+	if (!((IOAPIC_PBASE <= pa) &&
+	       (pa + PGSIZE <= IOAPIC_PBASE + APIC_SIZE))) {
+		printk("Got an IOAPIC at %p, ignoring...\n", pa);
+		return;
+	}
 	assert((IOAPIC_PBASE <= pa) &&
 	       (pa + PGSIZE <= IOAPIC_PBASE + APIC_SIZE));
 	/*
diff --git a/kern/arch/x86/ros/arch.h b/kern/arch/x86/ros/arch.h
index a09129b..046f24c 100644
--- a/kern/arch/x86/ros/arch.h
+++ b/kern/arch/x86/ros/arch.h
@@ -1,3 +1,3 @@
 #pragma once
 
-#define MAX_NUM_CORES				255
+#define MAX_NUM_CORES				256
diff --git a/kern/arch/x86/smp_boot.c b/kern/arch/x86/smp_boot.c
index 0f1bb4b..bad72c5 100644
--- a/kern/arch/x86/smp_boot.c
+++ b/kern/arch/x86/smp_boot.c
@@ -203,6 +203,12 @@
 		     num_cores, x86_num_cores_booted, x86_num_cores_booted);
 		num_cores = x86_num_cores_booted;
 	}
+
+	if (num_cores > 255) {
+		warn("XXX %d cores booted, limiting to 254\n", num_cores);
+		num_cores = 254;
+	}
+
 	// Dealloc the temp shared stack
 	page_decref(smp_stack);
 
diff --git a/kern/arch/x86/x86.h b/kern/arch/x86/x86.h
index 1a7040a..5075a39 100644
--- a/kern/arch/x86/x86.h
+++ b/kern/arch/x86/x86.h
@@ -54,9 +54,6 @@
 /* CPUID */
 #define CPUID_PSE_SUPPORT	0x00000008
 
-/* Arch Constants */
-#define MAX_NUM_CORES		255
-
 #define X86_REG_BP		"rbp"
 #define X86_REG_SP		"rsp"
 #define X86_REG_IP		"rip"
diff --git a/kern/src/pmap.c b/kern/src/pmap.c
index ebdc1e8..b8305e1 100644
--- a/kern/src/pmap.c
+++ b/kern/src/pmap.c
@@ -105,8 +105,21 @@
 
 	if (entry->type != MULTIBOOT_MEMORY_AVAILABLE)
 		return;
-	if (!*boot_zone || (sizeof_mboot_mmentry(entry) >
-	                   sizeof_mboot_mmentry(*boot_zone)))
+
+	if (!*boot_zone)
+		*boot_zone = entry;
+
+	// XXX we need the bootzone to be in the temporary mapping set from
+	// assembly.  i.e < 512 GB for KERNBASE.  usually is this one...
+	#define MAGIC_REGION 0x100000000
+	if ((*boot_zone)->addr == MAGIC_REGION)
+		return;
+	if (entry->addr == MAGIC_REGION) {
+		*boot_zone = entry;
+		return;
+	}
+
+	if ((sizeof_mboot_mmentry(entry) > sizeof_mboot_mmentry(*boot_zone)))
 		*boot_zone = entry;
 }