Changes in tools/mkfat.py [cc1a727:67435b1] in mainline

File:

• tools/mkfat.py (modified) (5 diffs)

tools/mkfat.py

@@ -168 +168 @@
 """
 
-def mangle_fname(name):
-        # FIXME: filter illegal characters
-        parts = name.split('.')
-        
-        if len(parts) > 0:
-                fname = parts[0]
-        else:
-                fname = ''
-        
-        if len(fname) > 8:
-                sys.stdout.write("mkfat.py: error: Directory entry " + name +
-                    " base name is longer than 8 characters\n")
-                sys.exit(1);
-        
-        return (fname + '          ').upper()[0:8]
-
-def mangle_ext(name):
-        # FIXME: filter illegal characters
-        parts = name.split('.')
-        
-        if len(parts) > 1:
-                ext = parts[1]
-        else:
-                ext = ''
-        
-        if len(parts) > 2:
-                sys.stdout.write("mkfat.py: error: Directory entry " + name +
-                    " has more than one extension\n")
-                sys.exit(1);
-        
-        if len(ext) > 3:
-                sys.stdout.write("mkfat.py: error: Directory entry " + name +
-                    " extension is longer than 3 characters\n")
-                sys.exit(1);
-        
-        return (ext + '   ').upper()[0:3]
-
-def create_dirent(name, directory, cluster, size):
+LFN_DIR_ENTRY = """little:
+        uint8_t seq                /* sequence number */
+        char name1[10]             /* first part of the name */
+        uint8_t attr               /* attributes */
+        uint8_t rec_type           /* LFN record type */
+        uint8_t checksum           /* LFN checksum */
+        char name2[12]             /* second part of the name */
+        uint16_t cluster           /* cluster */
+        char name3[4]              /* third part of the name */
+"""
+
+lchars = set(['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
+              'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
+              'U', 'V', 'W', 'X', 'Y', 'Z',
+              '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+              '!', '#', '$', '%', '&', '\'', '(', ')', '-', '@',
+              '^', '_', '`', '{', '}', '~', '.'])
+
+def fat_lchars(name):
+        "Filter FAT legal characters"
+        
+        filtered_name = b''
+        filtered = False
+        
+        for char in name.encode('ascii', 'replace').upper():
+                if char in lchars:
+                        filtered_name += char
+                else:
+                        filtered_name += b'_'
+                        filtered = True
+        
+        return (filtered_name, filtered)
+
+def fat_name83(name, name83_list):
+        "Create a 8.3 name for the given name"
+        
+        ascii_name, lfn = fat_lchars(name)
+        # Splitting works only on strings, not on bytes
+        ascii_parts = ascii_name.decode('utf8').split('.')
+        
+        short_name = ''
+        short_ext = ''
+        
+        if len(ascii_name) > 11:
+                lfn = True
+        
+        if len(ascii_parts) > 0:
+                short_name = ascii_parts[0]
+                if len(short_name) > 8:
+                        lfn = True
+        
+        if len(ascii_parts) > 1:
+                short_ext = ascii_parts[-1]
+                if len(short_ext) > 3:
+                        lfn = True
+        
+        if len(ascii_parts) > 2:
+                lfn = True
+        
+        if lfn == False:
+                name83_list.append(short_name + '.' + short_ext)
+                return (short_name.ljust(8)[0:8], short_ext.ljust(3)[0:3], False)
+        
+        # For filenames with multiple extensions, we treat the last one
+        # as the actual extension. The rest of the filename is stripped
+        # of dots and concatenated to form the short name
+        for part in ascii_parts[1:-1]:
+                short_name += part
+        
+        for number in range(1, 999999):
+                number_str = ('~' + str(number)).upper()
+                
+                if len(short_name) + len(number_str) > 8:
+                        short_name = short_name[0:8 - len(number_str)]
+                
+                short_name += number_str;
+                
+                if not (short_name + '.' + short_ext) in name83_list:
+                        break
+        
+        name83_list.append(short_name + '.' + short_ext)
+        return (short_name.ljust(8)[0:8], short_ext.ljust(3)[0:3], True)
+
+def create_lfn_dirent(name, seq, checksum):
+        "Create LFN directory entry"
+        
+        entry = xstruct.create(LFN_DIR_ENTRY)
+        name_rest = name[26:]
+        
+        if len(name_rest) > 0:
+                entry.seq = seq
+        else:
+                entry.seq = seq | 0x40
+        
+        entry.name1 = name[0:10]
+        entry.name2 = name[10:22]
+        entry.name3 = name[22:26]
+        
+        entry.attr = 0x0F
+        entry.rec_type = 0
+        entry.checksum = checksum
+        entry.cluster = 0
+        
+        return (entry, name_rest)
+
+def lfn_checksum(name):
+        "Calculate LFN checksum"
+        
+        checksum = 0
+        for i in range(0, 11):
+                checksum = (((checksum & 1) << 7) + (checksum >> 1) + ord(name[i])) & 0xFF
+        
+        return checksum
+
+def create_dirent(name, name83_list, directory, cluster, size):
+        short_name, short_ext, lfn = fat_name83(name, name83_list)
+        
         dir_entry = xstruct.create(DIR_ENTRY)
         
-        dir_entry.name = mangle_fname(name).encode('ascii')
-        dir_entry.ext = mangle_ext(name).encode('ascii')
+        dir_entry.name = short_name
+        dir_entry.ext = short_ext
         
         if (directory):
@@ -230 +309 @@
                 dir_entry.size = size
         
-        return dir_entry
+        if not lfn:
+                return [dir_entry]
+        
+        long_name = name.encode('utf_16_le')
+        entries = [dir_entry]
+        
+        seq = 1
+        checksum = lfn_checksum(dir_entry.name + dir_entry.ext)
+        
+        while len(long_name) > 0:
+                long_entry, long_name = create_lfn_dirent(long_name, seq, checksum)
+                entries.append(long_entry)
+                seq += 1
+        
+        entries.reverse()
+        return entries
 
 def create_dot_dirent(empty_cluster):
@@ -274 +368 @@
         
         directory = []
-        
-        if (not head):
+        name83_list = []
+        
+        if not head:
                 # Directory cluster preallocation
                 empty_cluster = fat.index(0)
-                fat[empty_cluster] = 0xffff
+                fat[empty_cluster] = 0xFFFF
                 
                 directory.append(create_dot_dirent(empty_cluster))
@@ -285 +380 @@
                 empty_cluster = 0
         
-        for item in listdir_items(root):                
+        for item in listdir_items(root):
                 if item.is_file:
                         rv = write_file(item, outf, cluster_size, data_start, fat, reserved_clusters)
-                        directory.append(create_dirent(item.name, False, rv[0], rv[1]))
+                        directory.extend(create_dirent(item.name, name83_list, False, rv[0], rv[1]))
                 elif item.is_dir:
                         rv = recursion(False, item.path, outf, cluster_size, root_start, data_start, fat, reserved_clusters, dirent_size, empty_cluster)
-                        directory.append(create_dirent(item.name, True, rv[0], rv[1]))
-        
-        if (head):
+                        directory.extend(create_dirent(item.name, name83_list, True, rv[0], rv[1]))
+        
+        if head:
                 outf.seek(root_start)
                 for dir_entry in directory:
@@ -448 +543 @@
         
         outf.close()
-        
+
 if __name__ == '__main__':
         main()