Index: .gitignore
===================================================================
--- .gitignore	(revision db8568a349d4d49bb9a4c9b6a7f3bca32a223b4b)
+++ .gitignore	(revision 5773e827cf0567542d18c932dd0f0b24725b01ca)
@@ -14,5 +14,4 @@
 /Makefile.config
 /PKG
-/QEMU_EFI_ARM64.fd
 /common.h
 /config.h
Index: boot/arch/arm64/src/main.c
===================================================================
--- boot/arch/arm64/src/main.c	(revision db8568a349d4d49bb9a4c9b6a7f3bca32a223b4b)
+++ boot/arch/arm64/src/main.c	(revision 5773e827cf0567542d18c932dd0f0b24725b01ca)
@@ -191,10 +191,8 @@
 
 	/* Statically check PAGE_SIZE and BOOT_OFFSET. */
-#if PAGE_SIZE != 4096
-#error Unsupported PAGE_SIZE
-#endif
-#if !IS_ALIGNED(BOOT_OFFSET, PAGE_SIZE)
-#error Unsupported BOOT_OFFSET
-#endif
+	_Static_assert(PAGE_SIZE == 4096, "PAGE_SIZE must be equal to 4096");
+	_Static_assert(IS_ALIGNED(BOOT_OFFSET, PAGE_SIZE),
+	    "BOOT_OFFSET must be a multiple of PAGE_SIZE");
+
 	/*
 	 * Dynamically check the memory base. The condition should be always
Index: kernel/arch/arm64/src/interrupt.c
===================================================================
--- kernel/arch/arm64/src/interrupt.c	(revision db8568a349d4d49bb9a4c9b6a7f3bca32a223b4b)
+++ kernel/arch/arm64/src/interrupt.c	(revision 5773e827cf0567542d18c932dd0f0b24725b01ca)
@@ -53,5 +53,5 @@
 	DAIF_write(daif | DAIF_IRQ_FLAG);
 
-	return (daif >> DAIF_IRQ_SHIFT) & 1;
+	return daif & DAIF_IRQ_FLAG;
 }
 
@@ -66,5 +66,5 @@
 	DAIF_write(daif & ~DAIF_IRQ_FLAG);
 
-	return (daif >> DAIF_IRQ_SHIFT) & 1;
+	return daif & DAIF_IRQ_FLAG;
 }
 
@@ -77,6 +77,5 @@
 	uint64_t daif = DAIF_read();
 
-	DAIF_write((daif & ~DAIF_IRQ_FLAG) |
-	    ((ipl & 1) << DAIF_IRQ_SHIFT));
+	DAIF_write((daif & ~DAIF_IRQ_FLAG) | (ipl & DAIF_IRQ_FLAG));
 }
 
@@ -87,5 +86,5 @@
 ipl_t interrupts_read(void)
 {
-	return (DAIF_read() >> DAIF_IRQ_SHIFT) & 1;
+	return DAIF_read() & DAIF_IRQ_FLAG;
 }
 
Index: tools/ew.py
===================================================================
--- tools/ew.py	(revision db8568a349d4d49bb9a4c9b6a7f3bca32a223b4b)
+++ tools/ew.py	(revision 5773e827cf0567542d18c932dd0f0b24725b01ca)
@@ -89,4 +89,22 @@
 	return '-cpu 4Kc'
 
+def find_firmware(name, environ_var, default_paths, extra_info=None):
+	"""Find firmware image(s)."""
+
+	if environ_var in os.environ:
+		return os.environ[environ_var]
+
+	for path in default_paths:
+		if os.path.exists(path):
+			return path
+
+	sys.stderr.write("Cannot find %s binary image(s)!\n" % name)
+	sys.stderr.write(
+	    "Either set %s environment variable accordingly or place the image(s) in one of the default locations: %s.\n" %
+	    (environ_var, ", ".join(default_paths)))
+	if extra_info is not None:
+		sys.stderr.write(extra_info)
+	return None
+
 def platform_to_qemu_options(platform, machine, processor):
 	if platform == 'amd64':
@@ -95,19 +113,19 @@
 		return 'system-arm', '-M integratorcp'
 	elif platform == 'arm64':
-		# Check that ROM image is present. Provide the user with
-		# appropriate steps to fix this problem.
-		if not os.path.exists('QEMU_EFI_ARM64.fd'):
-			sys.stderr.write('Could not find ' +
-			    '\'QEMU_EFI_ARM64.fd\' which is expected to ' +
-			    'contain EDK2 firmware image.\n')
-			sys.stderr.write('Pre-built image can be obtained by ' +
-			    'running the following command:\n')
-			sys.stderr.write('$ wget http://snapshots.linaro.org/' +
-			    'components/kernel/leg-virt-tianocore-edk2-' +
-			    'upstream/latest/QEMU-AARCH64/RELEASE_GCC49/' +
-			    'QEMU_EFI.fd -O QEMU_EFI_ARM64.fd\n')
+		# Search for the EDK2 firmware image
+		default_paths = (
+			'/usr/local/qemu-efi-aarch64/QEMU_EFI.fd', # Custom
+			'/usr/share/edk2/aarch64/QEMU_EFI.fd',     # Fedora
+			'/usr/share/qemu-efi-aarch64/QEMU_EFI.fd', # Ubuntu
+		)
+		extra_info = ("Pre-compiled binary can be obtained from "
+		    "http://snapshots.linaro.org/components/kernel/leg-virt-tianocore-edk2-upstream/latest/QEMU-AARCH64/RELEASE_GCC49/QEMU_EFI.fd.\n")
+		efi_path = find_firmware(
+		    "EDK2", 'EW_QEMU_EFI_AARCH64', default_paths, extra_info)
+		if efi_path is None:
 			raise Exception
+
 		return 'system-aarch64', \
-		    '-M virt -cpu cortex-a57 -m 1024 -bios QEMU_EFI_ARM64.fd'
+		    '-M virt -cpu cortex-a57 -m 1024 -bios %s' % efi_path
 	elif platform == 'ia32':
 		return 'system-i386', pc_options(32)
@@ -124,16 +142,10 @@
 		if processor == 'us':
 			return 'system-sparc64', '-M sun4u --prom-env boot-args="console=devices/\\hw\\pci0\\01:01.0\\com1\\a"'
-		elif processor == 'sun4v':
-			default_path = '/usr/local/opensparc/image/'
-		try:
-			if os.path.exists(default_path):
-				opensparc_bins = default_path
-			elif os.path.exists(os.environ['OPENSPARC_BINARIES']):
-				opensparc_bins = os.environ['OPENSPARC_BINARIES']
-			else:
-				raise Exception
-		except:
-			print("Cannot find OpenSPARC binary images!")
-			print("Either set OPENSPARC_BINARIES environment variable accordingly or place the images in %s." % (default_path))
+
+		# processor = 'sun4v'
+		opensparc_bins = find_firmware(
+		    "OpenSPARC", 'OPENSPARC_BINARIES',
+		    ('/usr/local/opensparc/image/', ))
+		if opensparc_bins is None:
 			raise Exception