Index: sys/powerpc/aim/aim_machdep.c
===================================================================
--- sys/powerpc/aim/aim_machdep.c
+++ sys/powerpc/aim/aim_machdep.c
@@ -455,13 +455,35 @@
 
 #endif
 
+/*
+ * These functions need to provide addresses that both (a) work in real mode
+ * (or whatever mode/circumstances the kernel is in in early boot (now) and
+ * (b) can still, in principle, work once the kernel is going. Because these
+ * rely on existing mappings/real mode, unmap is a no-op.
+ */
 vm_offset_t
 pmap_early_io_map(vm_paddr_t pa, vm_size_t size)
 {
+	KASSERT(!pmap_bootstrapped, ("Not available after PMAP started!"));
 
-	return (pa);
+	/*
+	 * If we have the MMU up in early boot, assume it is 1:1. Otherwise,
+	 * try to get the address in a memory region compatible with the
+	 * direct map for efficiency later.
+	 */
+	if (mfmsr() & PSL_DR)
+		return (pa);
+	else
+		return (DMAP_BASE_ADDRESS + pa);
 }
 
+void
+pmap_early_io_unmap(vm_offset_t va, vm_size_t size)
+{
+
+	KASSERT(!pmap_bootstrapped, ("Not available after PMAP started!"));
+}
+
 /* From p3-53 of the MPC7450 RISC Microprocessor Family Reference Manual */
 void
 flush_disable_caches(void)
Index: sys/powerpc/aim/mmu_oea64.c
===================================================================
--- sys/powerpc/aim/mmu_oea64.c
+++ sys/powerpc/aim/mmu_oea64.c
@@ -551,7 +551,8 @@
 			/* If this address is direct-mapped, skip remapping */
 			if (hw_direct_map &&
 			    translations[i].om_va == PHYS_TO_DMAP(pa_base) &&
-			    moea64_calc_wimg(pa_base + off, VM_MEMATTR_DEFAULT) 			    == LPTE_M)
+			    moea64_calc_wimg(pa_base + off, VM_MEMATTR_DEFAULT)
+ 			    == LPTE_M)
 				continue;
 
 			PMAP_LOCK(kernel_pmap);
@@ -664,25 +665,27 @@
 		  }
 		}
 		PMAP_UNLOCK(kernel_pmap);
-	} else {
-		size = moea64_bpvo_pool_size*sizeof(struct pvo_entry);
-		off = (vm_offset_t)(moea64_bpvo_pool);
-		for (pa = off; pa < off + size; pa += PAGE_SIZE) 
-		moea64_kenter(mmup, pa, pa);
+	}
 
-		/*
-		 * Map certain important things, like ourselves.
-		 *
-		 * NOTE: We do not map the exception vector space. That code is
-		 * used only in real mode, and leaving it unmapped allows us to
-		 * catch NULL pointer deferences, instead of making NULL a valid
-		 * address.
-		 */
+	/*
+	 * Make sure the kernel and BPVO pool stay mapped on systems either
+	 * without a direct map or on which the kernel is not already executing
+	 * out of the direct-mapped region.
+	 */
 
+	if (!hw_direct_map || kernelstart < DMAP_BASE_ADDRESS) {
 		for (pa = kernelstart & ~PAGE_MASK; pa < kernelend;
-		    pa += PAGE_SIZE) 
+		    pa += PAGE_SIZE)
 			moea64_kenter(mmup, pa, pa);
 	}
+
+	if (!hw_direct_map || (vm_offset_t)(moea64_bpvo_pool) <
+	    DMAP_BASE_ADDRESS) {
+		size = moea64_bpvo_pool_size*sizeof(struct pvo_entry);
+		off = (vm_offset_t)(moea64_bpvo_pool);
+		for (pa = off; pa < off + size; pa += PAGE_SIZE) 
+			moea64_kenter(mmup, pa, pa);
+	}
 	ENABLE_TRANS(msr);
 
 	/*
@@ -826,6 +829,11 @@
 		moea64_bpvo_pool_size*sizeof(struct pvo_entry), 0);
 	moea64_bpvo_pool_index = 0;
 
+	/* If in real mode, place at address usable through the direct map */
+	if (hw_direct_map && !(mfmsr() & PSL_DR))
+		moea64_bpvo_pool = (struct pvo_entry *)
+		    PHYS_TO_DMAP((uintptr_t)moea64_bpvo_pool);
+
 	/*
 	 * Make sure kernel vsid is allocated as well as VSID 0.
 	 */
@@ -898,12 +906,11 @@
 		Maxmem = max(Maxmem, powerpc_btop(phys_avail[i + 1]));
 
 	/*
-	 * Initialize MMU and remap early physical mappings
+	 * Initialize MMU.
 	 */
 	MMU_CPU_BOOTSTRAP(mmup,0);
 	mtmsr(mfmsr() | PSL_DR | PSL_IR);
 	pmap_bootstrapped++;
-	bs_remap_earlyboot();
 
 	/*
 	 * Set the start and end of kva.
@@ -918,6 +925,11 @@
 	for (va = virtual_avail; va < virtual_end; va += SEGMENT_LENGTH)
 		moea64_bootstrap_slb_prefault(va, 0);
 	#endif
+	
+	/*
+	 * Remap any early IO mappings (console framebuffer, etc.)
+	 */
+	bs_remap_earlyboot();
 
 	/*
 	 * Figure out how far we can extend virtual_end into segment 16
@@ -1826,10 +1838,11 @@
 
 	/*
 	 * Shortcut the direct-mapped case when applicable.  We never put
-	 * anything but 1:1 mappings below VM_MIN_KERNEL_ADDRESS.
+	 * anything but 1:1 (or 62-bit aliased) mappings below
+	 * VM_MIN_KERNEL_ADDRESS.
 	 */
 	if (va < VM_MIN_KERNEL_ADDRESS)
-		return (va);
+		return (va & ~DMAP_BASE_ADDRESS);
 
 	PMAP_LOCK(kernel_pmap);
 	pvo = moea64_pvo_find_va(kernel_pmap, va);
@@ -2565,12 +2578,15 @@
 	 * Update vm about page writeability/executability if managed
 	 */
 	PV_LOCKASSERT(pvo->pvo_pte.pa & LPTE_RPGN);
-	pg = PHYS_TO_VM_PAGE(pvo->pvo_pte.pa & LPTE_RPGN);
+	if (pvo->pvo_vaddr & PVO_MANAGED) {
+		pg = PHYS_TO_VM_PAGE(pvo->pvo_pte.pa & LPTE_RPGN);
 
-	if ((pvo->pvo_vaddr & PVO_MANAGED) && pg != NULL) {
-		LIST_REMOVE(pvo, pvo_vlink);
-		if (LIST_EMPTY(vm_page_to_pvoh(pg)))
-			vm_page_aflag_clear(pg, PGA_WRITEABLE | PGA_EXECUTABLE);
+		if (pg != NULL) {
+			LIST_REMOVE(pvo, pvo_vlink);
+			if (LIST_EMPTY(vm_page_to_pvoh(pg)))
+				vm_page_aflag_clear(pg,
+				    PGA_WRITEABLE | PGA_EXECUTABLE);
+		}
 	}
 
 	moea64_pvo_entries--;
@@ -2677,8 +2693,11 @@
 	vm_offset_t ppa;
 	int error = 0;
 
+	if (hw_direct_map && mem_valid(pa, size) == 0)
+		return (0);
+
 	PMAP_LOCK(kernel_pmap);
-	key.pvo_vaddr = ppa = pa & ~ADDR_POFF;
+	key.pvo_vaddr = ppa = (DMAP_BASE_ADDRESS + pa) & ~ADDR_POFF;
 	for (pvo = RB_FIND(pvo_tree, &kernel_pmap->pmap_pvo, &key);
 	    ppa < pa + size; ppa += PAGE_SIZE,
 	    pvo = RB_NEXT(pvo_tree, &kernel_pmap->pmap_pvo, pvo)) {
Index: sys/powerpc/aim/moea64_native.c
===================================================================
--- sys/powerpc/aim/moea64_native.c
+++ sys/powerpc/aim/moea64_native.c
@@ -444,9 +444,12 @@
 	moea64_mid_bootstrap(mmup, kernelstart, kernelend);
 
 	/*
-	 * Add a mapping for the page table itself if there is no direct map.
+	 * Add a mapping for the page table itself if there is no direct map
+	 * or the kernel is executing in a way that does let us make use of
+	 * real-aliased addresses.
 	 */
-	if (!hw_direct_map) {
+	if (!hw_direct_map ||
+	    (vm_offset_t)moea64_pteg_table < DMAP_BASE_ADDRESS) {
 		size = moea64_pteg_count * sizeof(struct lpteg);
 		off = (vm_offset_t)(moea64_pteg_table);
 		DISABLE_TRANS(msr);
Index: sys/powerpc/aim/slb.c
===================================================================
--- sys/powerpc/aim/slb.c
+++ sys/powerpc/aim/slb.c
@@ -207,13 +207,16 @@
 	/* Set kernel VSID to deterministic value */
 	slbv = (KERNEL_VSID((uintptr_t)va >> ADDR_SR_SHFT)) << SLBV_VSID_SHIFT;
 
-	/* Figure out if this is a large-page mapping */
-	if (hw_direct_map && va < VM_MIN_KERNEL_ADDRESS) {
+	/* 
+	 * Figure out if this is a large-page mapping.
+	 */
+	if (hw_direct_map && va > DMAP_BASE_ADDRESS && va < DMAP_MAX_ADDRESS) {
 		/*
 		 * XXX: If we have set up a direct map, assumes
 		 * all physical memory is mapped with large pages.
 		 */
-		if (mem_valid(va, 0) == 0)
+
+		if (mem_valid(DMAP_TO_PHYS(va), 0) == 0)
 			slbv |= SLBV_L;
 	}
 		
Index: sys/powerpc/aim/trap_subr64.S
===================================================================
--- sys/powerpc/aim/trap_subr64.S
+++ sys/powerpc/aim/trap_subr64.S
@@ -43,7 +43,9 @@
 #define GET_CPUINFO(r)  \
         mfsprg0  r
 #define GET_TOCBASE(r)  \
-	li	r,TRAP_TOCBASE;	/* Magic address for TOC */ \
+	lis	r,DMAP_BASE_ADDRESS@highesta;	/* To real-mode alias/dmap */ \
+	sldi	r,r,32;							\
+	ori	r,r,TRAP_TOCBASE;	/* Magic address for TOC */	\
 	ld	r,0(r)
 
 /*
Index: sys/powerpc/include/sr.h
===================================================================
--- sys/powerpc/include/sr.h
+++ sys/powerpc/include/sr.h
@@ -53,7 +53,7 @@
 #define	KERNEL2_SEGMENT	(0xfffff0 + KERNEL2_SR)
 #define	EMPTY_SEGMENT	0xfffff0
 #ifdef __powerpc64__
-#define	USER_ADDR	0xcffffffff0000000UL
+#define	USER_ADDR	0xeffffffff0000000UL
 #else
 #define	USER_ADDR	((uintptr_t)USER_SR << ADDR_SR_SHFT)
 #endif
Index: sys/powerpc/include/vmparam.h
===================================================================
--- sys/powerpc/include/vmparam.h
+++ sys/powerpc/include/vmparam.h
@@ -83,11 +83,7 @@
 #if !defined(LOCORE)
 #ifdef __powerpc64__
 #define	VM_MIN_ADDRESS		(0x0000000000000000UL)
-#ifdef AIM
-#define	VM_MAXUSER_ADDRESS	(0xfffffffffffff000UL)
-#else
-#define	VM_MAXUSER_ADDRESS	(0x7ffffffffffff000UL)
-#endif
+#define	VM_MAXUSER_ADDRESS	(0x3ffffffffffff000UL)
 #define	VM_MAX_ADDRESS		(0xffffffffffffffffUL)
 #else
 #define	VM_MIN_ADDRESS		((vm_offset_t)0)
@@ -99,7 +95,7 @@
 #ifdef BOOKE
 #define	VM_MIN_ADDRESS		0
 #ifdef __powerpc64__
-#define	VM_MAXUSER_ADDRESS	0x7ffffffffffff000
+#define	VM_MAXUSER_ADDRESS	0x3ffffffffffff000
 #else
 #define	VM_MAXUSER_ADDRESS	0x7ffff000
 #endif
@@ -110,8 +106,13 @@
 #define	FREEBSD32_USRSTACK	FREEBSD32_SHAREDPAGE
 
 #ifdef __powerpc64__
+#ifdef AIM
+#define	VM_MIN_KERNEL_ADDRESS		0xe000000000000000UL
+#define	VM_MAX_KERNEL_ADDRESS		0xe0000001c7ffffffUL
+#else
 #define	VM_MIN_KERNEL_ADDRESS		0xc000000000000000UL
 #define	VM_MAX_KERNEL_ADDRESS		0xc0000001c7ffffffUL
+#endif
 #define	VM_MAX_SAFE_KERNEL_ADDRESS	VM_MAX_KERNEL_ADDRESS
 #endif
 
@@ -243,14 +244,15 @@
 
 /*
  * We (usually) have a direct map of all physical memory, so provide
- * a macro to use to get the kernel VA address for a given PA. Returns
- * 0 if the direct map is unavailable. The location of the direct map
- * may not be 1:1 in future, so use of the macro is recommended.
+ * a macro to use to get the kernel VA address for a given PA. Check the
+ * value of PMAP_HAS_PMAP before using.
  */
 #ifdef __powerpc64__
-#define	DMAP_BASE_ADDRESS	0x0000000000000000UL
+#define	DMAP_BASE_ADDRESS	0xc000000000000000UL
+#define	DMAP_MAX_ADDRESS	0xcfffffffffffffffUL
 #else
 #define	DMAP_BASE_ADDRESS	0x00000000UL
+#define	DMAP_MAX_ADDRESS	0xbfffffffUL
 #endif
 
 #define	PMAP_HAS_DMAP	(hw_direct_map)
Index: sys/powerpc/ofw/ofw_machdep.c
===================================================================
--- sys/powerpc/ofw/ofw_machdep.c
+++ sys/powerpc/ofw/ofw_machdep.c
@@ -84,19 +84,20 @@
 __inline void
 ofw_save_trap_vec(char *save_trap_vec)
 {
-	if (!ofw_real_mode)
+	if (!ofw_real_mode || !hw_direct_map)
                 return;
 
-	bcopy((void *)EXC_RST, save_trap_vec, EXC_LAST - EXC_RST);
+	bcopy((void *)PHYS_TO_DMAP(EXC_RST), save_trap_vec, EXC_LAST - EXC_RST);
 }
 
 static __inline void
 ofw_restore_trap_vec(char *restore_trap_vec)
 {
-	if (!ofw_real_mode)
+	if (!ofw_real_mode || !hw_direct_map)
                 return;
 
-	bcopy(restore_trap_vec, (void *)EXC_RST, EXC_LAST - EXC_RST);
+	bcopy(restore_trap_vec, (void *)PHYS_TO_DMAP(EXC_RST),
+	    EXC_LAST - EXC_RST);
 	__syncicache(EXC_RSVD, EXC_LAST - EXC_RSVD);
 }
 
@@ -381,12 +382,6 @@
 #endif
 
 	fdt = fdt_ptr;
-
-	#ifdef FDT_DTB_STATIC
-	/* Check for a statically included blob */
-	if (fdt == NULL)
-		fdt = &fdt_static_dtb;
-	#endif
 }
 
 boolean_t
@@ -414,14 +409,52 @@
 	} else
 #endif
 	if (fdt != NULL) {
+		bus_space_tag_t fdt_bt;
+		vm_offset_t tmp_fdt_ptr;
+		vm_size_t fdt_size;
+		uintptr_t fdt_va;
+
 		status = OF_install(OFW_FDT, 0);
-
 		if (status != TRUE)
 			return status;
 
-		err = OF_init(fdt);
+		/* Get the FDT size for mapping if we can */
+		tmp_fdt_ptr = pmap_early_io_map((vm_paddr_t)fdt, PAGE_SIZE);
+		if (fdt_check_header((void *)tmp_fdt_ptr) != 0) {
+			pmap_early_io_unmap(tmp_fdt_ptr, PAGE_SIZE);
+			return FALSE;
+		}
+		fdt_size = fdt_totalsize((void *)tmp_fdt_ptr);
+		pmap_early_io_unmap(tmp_fdt_ptr, PAGE_SIZE);
+
+		/*
+		 * Map this for real. Use bus_space_map() to take advantage
+		 * of its auto-remapping function once the kernel is loaded.
+		 * This is a dirty hack, but what we have.
+		 */
+#ifdef _LITTLE_ENDIAN
+		fdt_bt = &bs_le_tag;
+#else
+		fdt_bt = &bs_be_tag;
+#endif
+		bus_space_map(fdt_bt, (vm_paddr_t)fdt, fdt_size, 0, &fdt_va);
+		    
+		err = OF_init((void *)fdt_va);
 	} 
 
+	#ifdef FDT_DTB_STATIC
+	/*
+	 * Check for a statically included blob already in the kernel and
+	 * needing no mapping.
+	 */
+	else {
+		status = OF_install(OFW_FDT, 0);
+		if (status != TRUE)
+			return status;
+		err = OF_init(&fdt_static_dtb);
+	}
+	#endif
+
 	if (err != 0) {
 		OF_install(NULL, 0);
 		status = FALSE;
Index: sys/powerpc/ofw/ofw_real.c
===================================================================
--- sys/powerpc/ofw/ofw_real.c
+++ sys/powerpc/ofw/ofw_real.c
@@ -223,7 +223,7 @@
 	 * we have a 32-bit virtual address to give OF.
 	 */
 
-	if (!ofw_real_mode && !hw_direct_map) 
+	if (!ofw_real_mode && (!hw_direct_map || DMAP_BASE_ADDRESS != 0)) 
 		pmap_kenter(of_bounce_phys, of_bounce_phys);
 
 	mtx_unlock(&of_bounce_mtx);
@@ -244,7 +244,7 @@
 		 * can use right now is memory mapped by firmware.
 		 */
 		if (!pmap_bootstrapped)
-			return (cell_t)(uintptr_t)buf;
+			return (cell_t)((uintptr_t)buf & ~DMAP_BASE_ADDRESS);
 
 		/*
 		 * XXX: It is possible for us to get called before the VM has
@@ -253,7 +253,8 @@
 		 * Copy into the emergency buffer, and reset at the end.
 		 */
 		of_bounce_virt = emergency_buffer;
-		of_bounce_phys = (vm_offset_t)of_bounce_virt;
+		of_bounce_phys = (vm_offset_t)of_bounce_virt &
+		    ~DMAP_BASE_ADDRESS;
 		of_bounce_size = sizeof(emergency_buffer);
 	}
 
@@ -261,7 +262,8 @@
 	 * Make sure the bounce page offset satisfies any reasonable
 	 * alignment constraint.
 	 */
-	of_bounce_offset += sizeof(register_t) - (of_bounce_offset % sizeof(register_t));
+	of_bounce_offset += sizeof(register_t) -
+	    (of_bounce_offset % sizeof(register_t));
 
 	if (of_bounce_offset + len > of_bounce_size) {
 		panic("Oversize Open Firmware call!");
Index: sys/powerpc/powerpc/bus_machdep.c
===================================================================
--- sys/powerpc/powerpc/bus_machdep.c
+++ sys/powerpc/powerpc/bus_machdep.c
@@ -115,7 +115,9 @@
 
 	for (i = 0; i < earlyboot_map_idx; i++) {
 		spa = earlyboot_mappings[i].addr;
-		if (spa == earlyboot_mappings[i].virt &&
+
+		if (hw_direct_map &&
+		   PHYS_TO_DMAP(spa) == earlyboot_mappings[i].virt &&
 		   pmap_dev_direct_mapped(spa, earlyboot_mappings[i].size) == 0)
 			continue;
 
Index: sys/powerpc/powerpc/genassym.c
===================================================================
--- sys/powerpc/powerpc/genassym.c
+++ sys/powerpc/powerpc/genassym.c
@@ -222,6 +222,7 @@
 ASSYM(SF_UC, offsetof(struct sigframe, sf_uc));
 
 ASSYM(KERNBASE, KERNBASE);
+ASSYM(DMAP_BASE_ADDRESS, DMAP_BASE_ADDRESS);
 ASSYM(MAXCOMLEN, MAXCOMLEN);
 
 #ifdef __powerpc64__
Index: sys/powerpc/powerpc/mem.c
===================================================================
--- sys/powerpc/powerpc/mem.c
+++ sys/powerpc/powerpc/mem.c
@@ -125,8 +125,9 @@
 				break;
 			}
 	
-			if (!pmap_dev_direct_mapped(v, cnt)) {
-				error = uiomove((void *)v, cnt, uio);
+			if (hw_direct_map && !pmap_dev_direct_mapped(v, cnt)) {
+				error = uiomove((void *)PHYS_TO_DMAP(v), cnt,
+				    uio);
 			} else {
 				m.phys_addr = trunc_page(v);
 				marr = &m;
Index: sys/powerpc/powerpc/uma_machdep.c
===================================================================
--- sys/powerpc/powerpc/uma_machdep.c
+++ sys/powerpc/powerpc/uma_machdep.c
@@ -94,7 +94,12 @@
 		pmap_remove(kernel_pmap,(vm_offset_t)mem,
 		    (vm_offset_t)mem + PAGE_SIZE);
 
-	m = PHYS_TO_VM_PAGE((vm_offset_t)mem);
+	if (hw_direct_map)
+		m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)mem));
+	else
+		m = PHYS_TO_VM_PAGE((vm_offset_t)mem);
+	KASSERT(m != NULL,
+	    ("Freeing UMA block at %p with no associated page", mem));
 	vm_page_unwire_noq(m);
 	vm_page_free(m);
 	atomic_subtract_int(&hw_uma_mdpages, 1);
Index: sys/powerpc/ps3/platform_ps3.c
===================================================================
--- sys/powerpc/ps3/platform_ps3.c
+++ sys/powerpc/ps3/platform_ps3.c
@@ -128,9 +128,6 @@
 	pmap_mmu_install("mmu_ps3", BUS_PROBE_SPECIFIC);
 	cpu_idle_hook = ps3_cpu_idle;
 
-	/* Set a breakpoint to make NULL an invalid address */
-	lv1_set_dabr(0x7 /* read and write, MMU on */, 2 /* kernel accesses */);
-
 	/* Record our PIR at boot for later */
 	ps3_boot_pir = mfspr(SPR_PIR);
 
@@ -226,7 +223,8 @@
 ps3_smp_start_cpu(platform_t plat, struct pcpu *pc)
 {
 	/* kernel is spinning on 0x40 == -1 right now */
-	volatile uint32_t *secondary_spin_sem = (uint32_t *)PHYS_TO_DMAP(0x40);
+	volatile uint32_t *secondary_spin_sem =
+	    (uint32_t *)PHYS_TO_DMAP((uintptr_t)0x40);
 	int remote_pir = pc->pc_hwref;
 	int timeout;