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e622656538c1f2303c050a298da9558524ea02c3
littlefs/scripts/dbgtag.py
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Christopher Haster e622656538 bmap: Tweaked bmap ranges, dropped in-flight tag for now 
New bmap range tags:

  LFS3_TAG_BMRANGE      0x033u  v--- --11 --11 uuuu
  LFS3_TAG_BMFREE       0x0330  v--- --11 --11 ----
  LFS3_TAG_BMINUSE      0x0331  v--- --11 --11 ---1
  LFS3_TAG_BMERASED     0x0332  v--- --11 --11 --1-
  LFS3_TAG_BMBAD        0x0333  v--- --11 --11 --11

Note 0x334-0x33f are still reserved for future bmap tags, but the new
encoding fits in the surprisingly common 2-bit subfield that may
deduplicate some decoding code.

Fitting in 2-bits is the main reason for this, now that in-flight ranges
look like they won't be worth exploring further. Worst case we can
always add more bm tags in the future. And it may even make sense to use
an entire bit for in-flight tags, since in theory the concept can apply
to more than just in-use blocks.

---

Another benefit of this encoding: In-use vs free is a bit check, and I
like the implication that an in-use + erased block can only be a bad
block.

No code changes:

                code          stack          ctx
  before:      37172           2352          684
  after:       37172 (+0.0%)   2352 (+0.0%)  684 (+0.0%)

                code          stack          ctx
  bmap before: 38844           2456          800
  bmap after:  38844 (+0.0%)   2456 (+0.0%)  800 (+0.0%)
2025-10-09 14:33:24 -05:00

362 lines
14 KiB
Python
Executable File
Raw Blame History

#!/usr/bin/env python3
# prevent local imports
if __name__ == "__main__":
__import__('sys').path.pop(0)
import io
import math as mt
import os
import struct
import sys
TAG_NULL = 0x0000 ## 0x0000 v--- ---- ---- ----
TAG_CONFIG = 0x0000 ## 0x00tt v--- ---- -ttt tttt
TAG_MAGIC = 0x0031 # 0x003r v--- ---- --11 --rr
TAG_VERSION = 0x0034 # 0x0034 v--- ---- --11 -1--
TAG_RCOMPAT = 0x0035 # 0x0035 v--- ---- --11 -1-1
TAG_WCOMPAT = 0x0036 # 0x0036 v--- ---- --11 -11-
TAG_OCOMPAT = 0x0037 # 0x0037 v--- ---- --11 -111
TAG_GEOMETRY = 0x0038 # 0x0038 v--- ---- --11 1---
TAG_NAMELIMIT = 0x0039 # 0x0039 v--- ---- --11 1--1
TAG_FILELIMIT = 0x003a # 0x003a v--- ---- --11 1-1-
TAG_GDELTA = 0x0100 ## 0x01tt v--- ---1 -ttt ttrr
TAG_GRMDELTA = 0x0100 # 0x0100 v--- ---1 ---- ----
TAG_GBMAPDELTA = 0x0104 # 0x0104 v--- ---1 ---- -1rr
TAG_NAME = 0x0200 ## 0x02tt v--- --1- -ttt tttt
TAG_BNAME = 0x0200 # 0x0200 v--- --1- ---- ----
TAG_REG = 0x0201 # 0x0201 v--- --1- ---- ---1
TAG_DIR = 0x0202 # 0x0202 v--- --1- ---- --1-
TAG_STICKYNOTE = 0x0203 # 0x0203 v--- --1- ---- --11
TAG_BOOKMARK = 0x0204 # 0x0204 v--- --1- ---- -1--
TAG_MNAME = 0x0220 # 0x0220 v--- --1- --1- ----
TAG_STRUCT = 0x0300 ## 0x03tt v--- --11 -ttt ttrr
TAG_BRANCH = 0x0300 # 0x030r v--- --11 ---- --rr
TAG_DATA = 0x0304 # 0x0304 v--- --11 ---- -1--
TAG_BLOCK = 0x0308 # 0x0308 v--- --11 ---- 1err
TAG_DID = 0x0314 # 0x0314 v--- --11 ---1 -1--
TAG_BSHRUB = 0x0318 # 0x0318 v--- --11 ---1 1---
TAG_BTREE = 0x031c # 0x031c v--- --11 ---1 11rr
TAG_MROOT = 0x0321 # 0x032r v--- --11 --1- --rr
TAG_MDIR = 0x0325 # 0x0324 v--- --11 --1- -1rr
TAG_MTREE = 0x032c # 0x032c v--- --11 --1- 11rr
TAG_BMRANGE = 0x0330 # 0x033u v--- --11 --11 uuuu
TAG_BMFREE = 0x0330 # 0x0330 v--- --11 --11 ----
TAG_BMINUSE = 0x0331 # 0x0331 v--- --11 --11 ---1
TAG_BMERASED = 0x0332 # 0x0332 v--- --11 --11 --1-
TAG_BMBAD = 0x0333 # 0x0333 v--- --11 --11 --11
TAG_ATTR = 0x0400 ## 0x04aa v--- -1-a -aaa aaaa
TAG_UATTR = 0x0400 # 0x04aa v--- -1-- -aaa aaaa
TAG_SATTR = 0x0500 # 0x05aa v--- -1-1 -aaa aaaa
TAG_SHRUB = 0x1000 ## 0x1kkk v--1 kkkk -kkk kkkk
TAG_ALT = 0x4000 ## 0x4kkk v1cd kkkk -kkk kkkk
TAG_B = 0x0000
TAG_R = 0x2000
TAG_LE = 0x0000
TAG_GT = 0x1000
TAG_CKSUM = 0x3000 ## 0x300p v-11 ---- ---- -pqq
TAG_PHASE = 0x0003
TAG_PERTURB = 0x0004
TAG_NOTE = 0x3100 ## 0x3100 v-11 ---1 ---- ----
TAG_ECKSUM = 0x3200 ## 0x3200 v-11 --1- ---- ----
TAG_GCKSUMDELTA = 0x3300 ## 0x3300 v-11 --11 ---- ----
# open with '-' for stdin/stdout
def openio(path, mode='r', buffering=-1):
import os
if path == '-':
if 'r' in mode:
return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
else:
return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
else:
return open(path, mode, buffering)
def fromleb128(data, j=0):
word = 0
d = 0
while j+d < len(data):
b = data[j+d]
word |= (b & 0x7f) << 7*d
word &= 0xffffffff
if not b & 0x80:
return word, d+1
d += 1
return word, d
def fromtag(data, j=0):
d = 0
tag = struct.unpack('>H', data[j:j+2].ljust(2, b'\0'))[0]; d += 2
weight, d_ = fromleb128(data, j+d); d += d_
size, d_ = fromleb128(data, j+d); d += d_
return tag>>15, tag&0x7fff, weight, size, d
# human readable tag repr
def tagrepr(tag, weight=None, size=None, *,
global_=False,
toff=None):
# null tags
if (tag & 0x6fff) == TAG_NULL:
return '%snull%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
' w%d' % weight if weight else '',
' %d' % size if size else '')
# config tags
elif (tag & 0x6f00) == TAG_CONFIG:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'magic' if (tag & 0xfff) == TAG_MAGIC
else 'version' if (tag & 0xfff) == TAG_VERSION
else 'rcompat' if (tag & 0xfff) == TAG_RCOMPAT
else 'wcompat' if (tag & 0xfff) == TAG_WCOMPAT
else 'ocompat' if (tag & 0xfff) == TAG_OCOMPAT
else 'geometry' if (tag & 0xfff) == TAG_GEOMETRY
else 'namelimit' if (tag & 0xfff) == TAG_NAMELIMIT
else 'filelimit' if (tag & 0xfff) == TAG_FILELIMIT
else 'config 0x%02x' % (tag & 0xff),
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# global-state delta tags
elif (tag & 0x6f00) == TAG_GDELTA:
if global_:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'grm' if (tag & 0xfff) == TAG_GRMDELTA
else 'gstate 0x%02x' % (tag & 0xff),
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
else:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'grmdelta' if (tag & 0xfff) == TAG_GRMDELTA
else 'gbmapdelta' if (tag & 0xfff) == TAG_GBMAPDELTA
else 'gdelta 0x%02x' % (tag & 0xff),
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# name tags, includes file types
elif (tag & 0x6f00) == TAG_NAME:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'bname' if (tag & 0xfff) == TAG_BNAME
else 'reg' if (tag & 0xfff) == TAG_REG
else 'dir' if (tag & 0xfff) == TAG_DIR
else 'stickynote' if (tag & 0xfff) == TAG_STICKYNOTE
else 'bookmark' if (tag & 0xfff) == TAG_BOOKMARK
else 'mname' if (tag & 0xfff) == TAG_MNAME
else 'name 0x%02x' % (tag & 0xff),
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# structure tags
elif (tag & 0x6f00) == TAG_STRUCT:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'branch' if (tag & 0xfff) == TAG_BRANCH
else 'data' if (tag & 0xfff) == TAG_DATA
else 'block' if (tag & 0xfff) == TAG_BLOCK
else 'did' if (tag & 0xfff) == TAG_DID
else 'bshrub' if (tag & 0xfff) == TAG_BSHRUB
else 'btree' if (tag & 0xfff) == TAG_BTREE
else 'mroot' if (tag & 0xfff) == TAG_MROOT
else 'mdir' if (tag & 0xfff) == TAG_MDIR
else 'mtree' if (tag & 0xfff) == TAG_MTREE
else 'bmfree' if (tag & 0xfff) == TAG_BMFREE
else 'bminuse' if (tag & 0xfff) == TAG_BMINUSE
else 'bmerased' if (tag & 0xfff) == TAG_BMERASED
else 'bmbad' if (tag & 0xfff) == TAG_BMBAD
else 'bmrange 0x%x' % (tag & 0xf)
if (tag & 0xff0) == TAG_BMRANGE
else 'struct 0x%02x' % (tag & 0xff),
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# custom attributes
elif (tag & 0x6e00) == TAG_ATTR:
return '%s%sattr 0x%02x%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
's' if tag & 0x100 else 'u',
((tag & 0x100) >> 1) + (tag & 0xff),
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# alt pointers
elif tag & TAG_ALT:
return 'alt%s%s 0x%03x%s%s' % (
'r' if tag & TAG_R else 'b',
'gt' if tag & TAG_GT else 'le',
tag & 0x0fff,
' w%d' % weight if weight is not None else '',
' 0x%x' % (0xffffffff & (toff-size))
if size and toff is not None
else ' -%d' % size if size
else '')
# checksum tags
elif (tag & 0x7f00) == TAG_CKSUM:
return 'cksum%s%s%s%s%s' % (
'q%d' % (tag & 0x3),
'p' if tag & TAG_PERTURB else '',
' 0x%02x' % (tag & 0xff) if tag & 0xf8 else '',
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# note tags
elif (tag & 0x7f00) == TAG_NOTE:
return 'note%s%s%s' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# erased-state checksum tags
elif (tag & 0x7f00) == TAG_ECKSUM:
return 'ecksum%s%s%s' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# global-checksum delta tags
elif (tag & 0x7f00) == TAG_GCKSUMDELTA:
if global_:
return 'gcksum%s%s%s' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
else:
return 'gcksumdelta%s%s%s' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % weight if weight else '',
' %s' % size if size is not None else '')
# unknown tags
else:
return '0x%04x%s%s' % (
tag,
' w%d' % weight if weight is not None else '',
' %d' % size if size is not None else '')
def list_tags():
# here be magic, parse our script's source to get to the tag comments
import inspect
import re
tags = []
tag_pattern = re.compile(
'^(?P<name>TAG_[^ ]*) *= *(?P<tag>[^ #]+) *#+ *(?P<comment>.*)$')
for line in inspect.getsourcelines(
inspect.getmodule(inspect.currentframe()))[0]:
m = tag_pattern.match(line)
if m:
tags.append(m.groups())
# find widths for alignment
w = [0]
for n, t, c in tags:
w[0] = max(w[0], len('LFSR_'+n))
# print
for n, t, c in tags:
print('%-*s %s' % (
w[0], 'LFSR_'+n,
c))
def dbg_tags(data, *,
word_bits=32):
# figure out tag size in bytes
if word_bits != 0:
n = 2 + 2*mt.ceil(word_bits / 7)
lines = []
# interpret as ints?
if not isinstance(data, bytes):
for tag in data:
lines.append((
' '.join('%02x' % b for b in struct.pack('>H', tag)),
tagrepr(tag)))
# interpret as bytes?
else:
j = 0
while j < len(data):
# bounded tags?
if word_bits != 0:
v, tag, w, size, d = fromtag(data[j:j+n])
# unbounded?
else:
v, tag, w, size, d = fromtag(data, j)
lines.append((
' '.join('%02x' % b for b in data[j:j+d]),
tagrepr(tag, w, size)))
j += d
# skip attached data if there is any
if not tag & TAG_ALT:
j += size
# figure out widths
w = [0]
for l in lines:
w[0] = max(w[0], len(l[0]))
# then print results
for l in lines:
print('%-*s %s' % (
w[0], l[0],
l[1]))
def main(tags, *,
list=False,
hex=False,
input=None,
word_bits=32):
import builtins
list_, list = list, builtins.list
hex_, hex = hex, builtins.hex
# list all known tags
if list_:
list_tags()
# interpret as a sequence of hex bytes
elif hex_:
bytes_ = [b for tag in tags for b in tag.split()]
dbg_tags(bytes(int(b, 16) for b in bytes_),
word_bits=word_bits)
# parse tags in a file
elif input:
with openio(input, 'rb') as f:
dbg_tags(f.read(),
word_bits=word_bits)
# default to interpreting as ints
else:
dbg_tags((int(tag, 0) for tag in tags),
word_bits=word_bits)
if __name__ == "__main__":
import argparse
import sys
parser = argparse.ArgumentParser(
description="Decode littlefs tags.",
allow_abbrev=False)
parser.add_argument(
'tags',
nargs='*',
help="Tags to decode.")
parser.add_argument(
'-l', '--list',
action='store_true',
help="List all known tags.")
parser.add_argument(
'-x', '--hex',
action='store_true',
help="Interpret as a sequence of hex bytes.")
parser.add_argument(
'-i', '--input',
help="Read tags from this file. Can use - for stdin.")
parser.add_argument(
'-w', '--word-bits',
nargs='?',
type=lambda x: int(x, 0),
const=0,
help="Word size in bits. 0 is unbounded. Defaults to 32.")
sys.exit(main(**{k: v
for k, v in vars(parser.parse_intermixed_args()).items()
if v is not None}))
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