mirror of
https://github.com/eledio-devices/thirdparty-littlefs.git
synced 2025-10-31 08:42:40 +01:00
cf87ba5375
Conceptually these are two separate operations. However, they are both only needed during mount, both require iteration over the linked-list of metadata-pairs, and both are independent from each other. Combining these into one gives us a nice code savings. Additionally, this greatly simplifies the lookup of the root directory. Initially we used a flag to indicate which superblock was root, since we didn't want to fetch more pairs than we needed to. But since we're going to fetch all metadata-pairs anyways, we can just use the last superblock we find as the indicator of our root directory.
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, 0x002): 'reg',
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(0x1ff, 0x003): '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 & 0x003ff000) >> 12
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size = (tag & 0x00000fff) >> 0
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iscrc = (type & 0x1f0) == 0x0f0
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data = file.read(size if size != 0xfff 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 != 0x3ff else '.',
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size if size != 0xfff 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 != 0xfff 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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