mirror of
https://github.com/eledio-devices/thirdparty-littlefs.git
synced 2025-10-31 08:42:40 +01:00
97a7191814
A rather humorous issue, we accidentally ended up mixing our file namespace with our superblocks. This meant if we created a file named "littlefs" it would reference the superblock and all sorts of things would break. Fixing this also highlighted another issue, the fact that the superblock always needs to come before any file entries in the directory. I didn't account for this in the initial B-tree design, but we need a higher ordering for superblocks + children + files than just name. To fix this I added ordering information in the 2 bits currently unused in the tag type. Though note that the size of these fields are flexible. 9-bit type field: [--- 9 ---] [1|- 3 -|- 2 -|- 3 -] ^ ^ ^ ^- type-specific info | | \------- ordering info | \------------- subtype \----------------- user bit
107 lines
2.8 KiB
Python
Executable File
107 lines
2.8 KiB
Python
Executable File
#!/usr/bin/env python2
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import struct
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import binascii
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TYPES = {
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(0x1ff, 0x011): 'create reg',
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(0x1ff, 0x010): 'create dir',
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(0x1ff, 0x001): 'superblock',
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(0x1ff, 0x020): 'delete',
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(0x1f0, 0x0e0): 'globals',
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(0x1ff, 0x080): 'tail soft',
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(0x1ff, 0x081): 'tail hard',
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(0x1f0, 0x0a0): 'crc',
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(0x1ff, 0x040): 'struct dir',
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(0x1ff, 0x041): 'struct inline',
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(0x1ff, 0x042): 'struct ctz',
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(0x100, 0x100): 'attr',
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}
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def typeof(type):
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for prefix in range(9):
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mask = 0x1ff & ~((1 << prefix)-1)
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if (mask, type & mask) in TYPES:
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return TYPES[mask, type & mask] + (
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' %0*x' % (prefix/4, type & ((1 << prefix)-1))
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if prefix else '')
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else:
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return '%02x' % type
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def main(*blocks):
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# find most recent block
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file = None
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rev = None
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crc = None
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versions = []
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for block in blocks:
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try:
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nfile = open(block, 'rb')
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ndata = nfile.read(4)
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ncrc = binascii.crc32(ndata)
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nrev, = struct.unpack('<I', ndata)
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assert rev != nrev
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if not file or ((rev - nrev) & 0x80000000):
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file = nfile
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rev = nrev
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crc = ncrc
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versions.append((nrev, '%s (rev %d)' % (block, nrev)))
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except (IOError, struct.error):
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pass
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if not file:
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print 'Bad metadata pair {%s}' % ', '.join(blocks)
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return 1
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print "--- %s ---" % ', '.join(v for _,v in sorted(versions, reverse=True))
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# go through each tag, print useful information
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print "%-4s %-8s %-14s %3s %3s %s" % (
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'off', 'tag', 'type', 'id', 'len', 'dump')
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tag = 0xffffffff
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off = 4
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while True:
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try:
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data = file.read(4)
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crc = binascii.crc32(data, crc)
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ntag, = struct.unpack('<I', data)
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except struct.error:
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break
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tag ^= ntag
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off += 4
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type = (tag & 0x7fc00000) >> 22
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id = (tag & 0x003fe000) >> 13
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size = (tag & 0x00001fff) >> 0
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iscrc = (type & 0x1f0) == 0x0f0
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data = file.read(size if size != 0x1fff else 0)
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if iscrc:
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crc = binascii.crc32(data[:4], crc)
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else:
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crc = binascii.crc32(data, crc)
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print '%04x: %08x %-14s %3s %3s %-23s %-8s' % (
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off, tag,
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typeof(type) + (' bad!' if iscrc and ~crc else ''),
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id if id != 0x1ff else '.',
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size if size != 0x1fff else 'x',
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' '.join('%02x' % ord(c) for c in data[:8]),
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''.join(c if c >= ' ' and c <= '~' else '.' for c in data[:8]))
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off += size if size != 0x1fff else 0
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if iscrc:
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crc = 0
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tag ^= (type & 1) << 31
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return 0
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if __name__ == "__main__":
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import sys
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sys.exit(main(*sys.argv[1:]))
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