diff --git a/src/system/boot/platform/openfirmware/arch/sparc/mmu.cpp b/src/system/boot/platform/openfirmware/arch/sparc/mmu.cpp
index 851850aa1d..28a70272d3 100644
--- a/src/system/boot/platform/openfirmware/arch/sparc/mmu.cpp
+++ b/src/system/boot/platform/openfirmware/arch/sparc/mmu.cpp
@@ -28,9 +28,10 @@
 #define PAGE_READ_ONLY	0x0002
 #define PAGE_READ_WRITE	0x0001
 
-// NULL is actually a possible physical address...
-//#define PHYSINVAL ((void *)-1)
-#define PHYSINVAL NULL
+// NULL is actually a possible physical address, so use -1 (which is
+// misaligned, so not a valid address) as the invalid physical address.
+#define PHYSINVAL ((void *)-1)
+//#define PHYSINVAL NULL
 
 //#define TRACE_MMU
 #ifdef TRACE_MMU
@@ -157,8 +158,8 @@ static bool
 map_range(void *virtualAddress, void *physicalAddress, size_t size, uint16 mode)
 {
 	// everything went fine, so lets mark the space as used.
-	int status = of_call_method(sMmuInstance, "map", 4, 0, mode, size,
-		virtualAddress, physicalAddress);
+	int status = of_call_method(sMmuInstance, "map", 5, 0, (uint64)mode, size,
+		virtualAddress, 0, physicalAddress);
 
 	if (status != 0) {
 		dprintf("map_range(base: %p, size: %" B_PRIuSIZE ") "
@@ -182,12 +183,17 @@ find_allocated_ranges(void **_exceptionHandlers)
 	struct translation_map {
 		void *PhysicalAddress() {
 			int64_t p = data;
+#if 0
+			// The openboot own "map?" word does not do this, so it must not
+			// be needed
 			// Sign extend
 			p <<= 23;
 			p >>= 23;
+#endif
 
-			// Remove low bits
-			p &= 0xFFFFFFFFFFFFE000ll;
+			// Keep only PA[40:13]
+			// FIXME later CPUs have some more bits here
+			p &= 0x000001FFFFFFE000ll;
 
 			return (void*)p;
 		}
@@ -219,7 +225,7 @@ find_allocated_ranges(void **_exceptionHandlers)
 	for (int i = 0; i < length; i++) {
 		struct translation_map *map = &translations[i];
 		bool keepRange = true;
-		TRACE("%i: map: %p, length %ld -> phy %p mode %d\n", i,
+		TRACE("%i: map: %p, length %ld -> phy %p mode %d: ", i,
 			map->virtual_address, map->length,
 			map->PhysicalAddress(), map->Mode());
 
@@ -246,8 +252,7 @@ find_allocated_ranges(void **_exceptionHandlers)
 		// insert range in virtual ranges to keep
 
 		if (keepRange) {
-			TRACE("%i: keeping free range starting at va %p\n", i,
-				map->virtual_address);
+			TRACE("keeping\n");
 
 			if (insert_virtual_range_to_keep(map->virtual_address,
 					map->length) != B_OK) {
@@ -255,6 +260,8 @@ find_allocated_ranges(void **_exceptionHandlers)
 					"(num ranges = %" B_PRIu32 ")\n",
 					gKernelArgs.num_virtual_allocated_ranges);
 			}
+		} else {
+			TRACE("dropping\n");
 		}
 
 		total += map->length;