A couple of bug fixes.

* mmu_get_virtual_mapping() should check that the page directory entry is
  present rather than assuming there's a page table there. This was resulting
  in some invalid mappings being created in the 64-bit virtual address space.
* arch_vm_init_end() should clear from KERNEL_LOAD_BASE to virtual_end, not
  from KERNEL_BASE. On x86_64 this was causing it to loop through ~512GB of
  address space, which obviously was taking quite a while.

src/system/boot/platform/bios_ia32/mmu.cpp

@@ -512,17 +512,18 @@ mmu_get_virtual_mapping(addr_t virtualAddress, addr_t *_physicalAddress)
 			(void *)virtualAddress);
 	}
 
-	uint32 *pageTable = (uint32 *)(sPageDirectory[virtualAddress
+	uint32 dirEntry = sPageDirectory[virtualAddress / (B_PAGE_SIZE * 1024)];
-		/ (B_PAGE_SIZE * 1024)] & 0xfffff000);
+	if ((dirEntry & (1 << 0)) == 0)
+		return false;
+
+	uint32 *pageTable = (uint32 *)(dirEntry & 0xfffff000);
 	uint32 tableEntry = pageTable[(virtualAddress % (B_PAGE_SIZE * 1024))
 		/ B_PAGE_SIZE];
+	if ((tableEntry & (1 << 0)) == 0)
+		return false;
 
-	if ((tableEntry & (1<<0)) != 0) {
 	*_physicalAddress = tableEntry & 0xFFFFF000;
 	return true;
-	} else {
-		return false;
-	}
 }
 
 

src/system/kernel/arch/x86/arch_cpu.cpp

@@ -897,10 +897,7 @@ arch_cpu_init_post_vm(kernel_args* args)
 	}
 #endif
 
-	// TODO x86_64
-#ifndef __x86_64
 	if (!apic_available())
-#endif
 		x86_init_fpu();
 	// else fpu gets set up in smp code
 

src/system/kernel/arch/x86/arch_vm.cpp

@@ -672,8 +672,8 @@ arch_vm_init_end(kernel_args *args)
 	TRACE(("arch_vm_init_endvm: entry\n"));
 
 	// throw away anything in the kernel_args.pgtable[] that's not yet mapped
-	vm_free_unused_boot_loader_range(KERNEL_BASE,
+	vm_free_unused_boot_loader_range(KERNEL_LOAD_BASE,
-		args->arch_args.virtual_end - KERNEL_BASE);
+		args->arch_args.virtual_end - KERNEL_LOAD_BASE);
 
 	return B_OK;
 }

src/system/kernel/arch/x86/paging/64bit/X86VMTranslationMap64Bit.cpp

@@ -539,7 +539,8 @@ X86VMTranslationMap64Bit::Query(addr_t virtualAddress,
 		| ((entry & X86_64_PTE_PRESENT) != 0 ? PAGE_PRESENT : 0);
 
 	TRACE("X86VMTranslationMap64Bit::Query(%#" B_PRIxADDR ") -> %#"
-		B_PRIxPHYSADDR ":\n", virtualAddress, *_physicalAddress);
+		B_PRIxPHYSADDR " %#" B_PRIx32 " (pte: %p %#" B_PRIx64 ")\n",
+		virtualAddress, *_physicalAddress, *_flags, pte, entry);
 
 	return B_OK;
 }