Index: tools/mkfat.py
===================================================================
--- tools/mkfat.py	(revision 700eaa90af7318438d4d5388b778c5083a21f188)
+++ tools/mkfat.py	(revision 0ec862da203b9b0c3934013365d787a9b0f09bf5)
@@ -95,4 +95,8 @@
 """
 
+EMPTY_SECTOR = """little:
+	padding[512]
+"""
+
 def usage(prname):
 	"Print usage syntax"
@@ -145,4 +149,23 @@
 	outf.write(boot_sector.pack())
 	
+	empty_sector = xstruct.create(EMPTY_SECTOR)
+	
+	# Reserved sectors (boot_sector.reserved - boot_sector)
+	for i in range(1, boot_sector.reserved):
+		outf.write(empty_sector.pack())
+	
+	# FAT tables
+	for i in range(0, boot_sector.fats):
+		for j in range(0, boot_sector.fat_sectors):
+			outf.write(empty_sector.pack())
+	
+	# Root directory
+	for i in range(0, root_size / sector_size):
+		outf.write(empty_sector.pack())
+	
+	# Data
+	for i in range(0, size / sector_size):
+		outf.write(empty_sector.pack())
+	
 	outf.close()