elf_mem_map 14 KB

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  1. #!/usr/bin/env python3
  2. import argparse
  3. import elftools.elf.elffile
  4. import elftools.dwarf.descriptions
  5. from collections import namedtuple
  6. from struct import unpack
  7. SRAM_OFFSET = 0x800000
  8. EEPROM_OFFSET = 0x810000
  9. FILL_BYTE = b'\0'
  10. Entry = namedtuple('Entry', ['name', 'loc', 'size', 'declpos'])
  11. Member = namedtuple('Member', ['name', 'off', 'size'])
  12. def array_inc(loc, dim, idx=0):
  13. if idx == len(dim):
  14. return True
  15. loc[idx] += 1
  16. if loc[idx] == dim[idx]:
  17. loc[idx] = 0
  18. return array_inc(loc, dim, idx+1)
  19. return False
  20. def get_type_size(type_DIE):
  21. while True:
  22. if 'DW_AT_byte_size' in type_DIE.attributes:
  23. return type_DIE, type_DIE.attributes.get('DW_AT_byte_size').value
  24. if 'DW_AT_type' not in type_DIE.attributes:
  25. return None
  26. type_DIE = type_DIE.get_DIE_from_attribute('DW_AT_type')
  27. def get_type_arrsize(type_DIE):
  28. size = get_type_size(type_DIE)
  29. if size is None:
  30. return None
  31. byte_size = size[1]
  32. if size[0].tag != 'DW_TAG_pointer_type':
  33. array_DIE = get_type_def(type_DIE, 'DW_TAG_array_type')
  34. if array_DIE is not None:
  35. for range_DIE in array_DIE.iter_children():
  36. if range_DIE.tag == 'DW_TAG_subrange_type' and \
  37. 'DW_AT_upper_bound' in range_DIE.attributes:
  38. dim = range_DIE.attributes['DW_AT_upper_bound'].value + 1
  39. byte_size *= dim
  40. return byte_size
  41. def get_type_def(type_DIE, type_tag):
  42. while True:
  43. if type_DIE.tag == type_tag:
  44. return type_DIE
  45. if 'DW_AT_type' not in type_DIE.attributes:
  46. return None
  47. type_DIE = type_DIE.get_DIE_from_attribute('DW_AT_type')
  48. def get_FORM_block1(attr):
  49. if attr.form != 'DW_FORM_block1':
  50. return None
  51. if attr.value[0] == 3: # OP_addr
  52. return int.from_bytes(attr.value[1:], 'little')
  53. if attr.value[0] == 35: # OP_plus_uconst (ULEB128)
  54. v = 0
  55. s = 0
  56. for b in attr.value[1:]:
  57. v |= (b & 0x7f) << s
  58. if b & 0x80 == 0:
  59. break
  60. s += 7
  61. return v
  62. return None
  63. def get_array_dims(DIE):
  64. array_DIE = get_type_def(DIE, 'DW_TAG_array_type')
  65. if array_DIE is None:
  66. return []
  67. array_dim = []
  68. for range_DIE in array_DIE.iter_children():
  69. if range_DIE.tag == 'DW_TAG_subrange_type' and \
  70. 'DW_AT_upper_bound' in range_DIE.attributes:
  71. array_dim.append(range_DIE.attributes['DW_AT_upper_bound'].value + 1)
  72. return array_dim
  73. def get_struct_members(DIE, size, expand_structs, struct_gaps):
  74. if not expand_structs or size[0].tag == 'DW_TAG_pointer_type':
  75. return []
  76. struct_DIE = get_type_def(DIE, 'DW_TAG_structure_type')
  77. if struct_DIE is None:
  78. return []
  79. members = []
  80. for member_DIE in struct_DIE.iter_children():
  81. if member_DIE.tag == 'DW_TAG_member' and 'DW_AT_name' in member_DIE.attributes:
  82. m_name = member_DIE.attributes['DW_AT_name'].value.decode('ascii')
  83. m_off = get_FORM_block1(member_DIE.attributes['DW_AT_data_member_location'])
  84. m_byte_size = get_type_size(member_DIE)[1]
  85. # still expand member arrays
  86. m_array_dim = get_array_dims(member_DIE)
  87. if m_byte_size == 1 and len(m_array_dim) > 1:
  88. # likely string, remove one dimension
  89. m_byte_size *= m_array_dim.pop()
  90. if len(m_array_dim) == 0 or (len(m_array_dim) == 1 and m_array_dim[0] == 1):
  91. # plain entry
  92. members.append(Member(m_name, m_off, m_byte_size))
  93. elif len(m_array_dim) == 1 and m_byte_size == 1:
  94. # likely string, avoid expansion
  95. members.append(Member(m_name + '[]', m_off, m_array_dim[0]))
  96. else:
  97. # expand array entries
  98. m_array_pos = m_off
  99. m_array_loc = [0] * len(m_array_dim)
  100. while True:
  101. # location index
  102. sfx = ''
  103. for d in range(len(m_array_dim)):
  104. sfx += '[{}]'.format(str(m_array_loc[d]).rjust(len(str(m_array_dim[d]-1)), '0'))
  105. members.append(Member(m_name + sfx, m_array_pos, m_byte_size))
  106. # advance
  107. if array_inc(m_array_loc, m_array_dim):
  108. break
  109. m_array_pos += m_byte_size
  110. if struct_gaps and len(members):
  111. # fill gaps in the middle
  112. members = list(sorted(members, key=lambda x: x.off))
  113. last_end = 0
  114. for n in range(len(members)):
  115. member = members[n]
  116. if member.off > last_end:
  117. members.append(Member('*UNKNOWN*', last_end, member.off - last_end))
  118. last_end = member.off + member.size
  119. if struct_gaps and len(members):
  120. # fill gap at the end
  121. members = list(sorted(members, key=lambda x: x.off))
  122. last = members[-1]
  123. last_end = last.off + last.size
  124. if size[1] > last_end:
  125. members.append(Member('*UNKNOWN*', last_end, byte_size - last_end))
  126. return members
  127. def get_elf_globals(path, expand_structs, struct_gaps=True):
  128. fd = open(path, "rb")
  129. if fd is None:
  130. return
  131. elffile = elftools.elf.elffile.ELFFile(fd)
  132. if elffile is None or not elffile.has_dwarf_info():
  133. return
  134. # probably not needed, since we're decoding expressions manually
  135. elftools.dwarf.descriptions.set_global_machine_arch(elffile.get_machine_arch())
  136. dwarfinfo = elffile.get_dwarf_info()
  137. grefs = []
  138. for CU in dwarfinfo.iter_CUs():
  139. file_entries = dwarfinfo.line_program_for_CU(CU).header["file_entry"]
  140. for DIE in CU.iter_DIEs():
  141. # handle only variable types
  142. if DIE.tag != 'DW_TAG_variable':
  143. continue
  144. if 'DW_AT_location' not in DIE.attributes:
  145. continue
  146. if 'DW_AT_name' not in DIE.attributes and \
  147. 'DW_AT_abstract_origin' not in DIE.attributes:
  148. continue
  149. # handle locations encoded directly as DW_OP_addr (leaf globals)
  150. loc = get_FORM_block1(DIE.attributes['DW_AT_location'])
  151. if loc is None or loc < SRAM_OFFSET or loc >= EEPROM_OFFSET:
  152. continue
  153. loc -= SRAM_OFFSET
  154. # variable name/type
  155. if 'DW_AT_name' not in DIE.attributes and \
  156. 'DW_AT_abstract_origin' in DIE.attributes:
  157. DIE = DIE.get_DIE_from_attribute('DW_AT_abstract_origin')
  158. if 'DW_AT_location' in DIE.attributes:
  159. # duplicate reference (handled directly), skip
  160. continue
  161. if 'DW_AT_name' not in DIE.attributes:
  162. continue
  163. if 'DW_AT_type' not in DIE.attributes:
  164. continue
  165. name = DIE.attributes['DW_AT_name'].value.decode('ascii')
  166. # get final storage size
  167. size = get_type_size(DIE)
  168. if size is None:
  169. continue
  170. byte_size = size[1]
  171. # location of main definition
  172. declpos = ''
  173. if 'DW_AT_decl_file' in DIE.attributes and \
  174. 'DW_AT_decl_line' in DIE.attributes:
  175. line = DIE.attributes['DW_AT_decl_line'].value
  176. fname = DIE.attributes['DW_AT_decl_file'].value
  177. if fname and fname - 1 < len(file_entries):
  178. fname = file_entries[fname-1].name.decode('ascii')
  179. declpos = '{}:{}'.format(fname, line)
  180. # fetch array dimensions (if known)
  181. array_dim = get_array_dims(DIE)
  182. # fetch structure members (one level only)
  183. members = get_struct_members(DIE, size, expand_structs, struct_gaps)
  184. def expand_members(entry, members):
  185. if len(members) == 0:
  186. grefs.append(entry)
  187. else:
  188. for member in members:
  189. grefs.append(Entry(entry.name + '.' + member.name,
  190. entry.loc + member.off, member.size,
  191. entry.declpos))
  192. if byte_size == 1 and len(array_dim) > 1:
  193. # likely string, remove one dimension
  194. byte_size *= array_dim.pop()
  195. if len(array_dim) == 0 or (len(array_dim) == 1 and array_dim[0] == 1):
  196. # plain entry
  197. expand_members(Entry(name, loc, byte_size, declpos), members)
  198. elif len(array_dim) == 1 and byte_size == 1:
  199. # likely string, avoid expansion
  200. grefs.append(Entry(name + '[]', loc, array_dim[0], declpos))
  201. else:
  202. # expand array entries
  203. array_pos = loc
  204. array_loc = [0] * len(array_dim)
  205. while True:
  206. # location index
  207. sfx = ''
  208. for d in range(len(array_dim)):
  209. sfx += '[{}]'.format(str(array_loc[d]).rjust(len(str(array_dim[d]-1)), '0'))
  210. expand_members(Entry(name + sfx, array_pos, byte_size, declpos), members)
  211. # advance
  212. if array_inc(array_loc, array_dim):
  213. break
  214. array_pos += byte_size
  215. return grefs
  216. def decode_dump(path):
  217. fd = open(path, 'r')
  218. if fd is None:
  219. return None
  220. buf_addr = None # starting address
  221. buf_data = None # data
  222. for line in fd:
  223. tokens = line.split(maxsplit=1)
  224. if len(tokens) == 0 or tokens[0] == 'ok':
  225. break
  226. elif len(tokens) < 2 or tokens[0] == 'D2':
  227. continue
  228. addr = int.from_bytes(bytes.fromhex(tokens[0]), 'big')
  229. data = bytes.fromhex(tokens[1])
  230. if buf_addr is None:
  231. buf_addr = addr
  232. buf_data = data
  233. else:
  234. # grow buffer as needed
  235. if addr < buf_addr:
  236. buf_data = FILL_BYTE * (buf_addr - addr)
  237. buf_addr = addr
  238. addr_end = addr + len(data)
  239. buf_end = buf_addr + len(buf_data)
  240. if addr_end > buf_end:
  241. buf_data += FILL_BYTE * (addr_end - buf_end)
  242. # replace new part
  243. rep_start = addr - buf_addr
  244. rep_end = rep_start + len(data)
  245. buf_data = buf_data[:rep_start] + data + buf_data[rep_end:]
  246. return (buf_addr, buf_data)
  247. def annotate_refs(grefs, addr, data, width, gaps=True, overlaps=True):
  248. last_end = None
  249. for entry in grefs:
  250. if entry.loc < addr:
  251. continue
  252. if entry.loc + entry.size > addr + len(data):
  253. continue
  254. pos = entry.loc-addr
  255. end_pos = pos + entry.size
  256. buf = data[pos:end_pos]
  257. buf_repr = ''
  258. if len(buf) in [1, 2, 4]:
  259. # attempt to decode as integers
  260. buf_repr += ' I:' + str(int.from_bytes(buf, 'little')).rjust(10)
  261. if len(buf) in [4, 8]:
  262. # attempt to decode as floats
  263. typ = 'f' if len(buf) == 4 else 'd'
  264. buf_repr += ' F:' + '{:10.3f}'.format(unpack(typ, buf)[0])
  265. if last_end is not None:
  266. if gaps and last_end < pos:
  267. # decode gaps
  268. gap_size = pos - last_end
  269. gap_buf = data[last_end:pos]
  270. print('{:04x} {} {:4} R:{}'.format(addr+last_end, "*UNKNOWN*".ljust(width),
  271. gap_size, gap_buf.hex()))
  272. if overlaps and last_end > pos + 1:
  273. gap_size = pos - last_end
  274. print('{:04x} {} {:4}'.format(addr+last_end, "*OVERLAP*".ljust(width), gap_size))
  275. print('{:04x} {} {:4}{} R:{}'.format(entry.loc, entry.name.ljust(width),
  276. entry.size, buf_repr, buf.hex()))
  277. last_end = end_pos
  278. def print_map(grefs):
  279. print('OFFSET\tSIZE\tNAME\tDECLPOS')
  280. for entry in grefs:
  281. print('{:x}\t{}\t{}\t{}'.format(entry.loc, entry.size, entry.name, entry.declpos))
  282. def main():
  283. ap = argparse.ArgumentParser(description="""
  284. Generate a symbol table map starting directly from an ELF
  285. firmware with DWARF2 debugging information.
  286. When used along with a memory dump obtained from the D2 g-code,
  287. show the value of each symbol which is within the address range.
  288. """)
  289. ap.add_argument('elf', help='ELF file containing DWARF2 debugging information')
  290. ap.add_argument('--no-gaps', action='store_true',
  291. help='do not dump memory inbetween known symbols')
  292. ap.add_argument('--no-expand-structs', action='store_true',
  293. help='do not decode structure data')
  294. ap.add_argument('--overlaps', action='store_true',
  295. help='annotate overlaps greater than 1 byte')
  296. ap.add_argument('--name-width', type=int, default=50,
  297. help='set name column width')
  298. g = ap.add_mutually_exclusive_group(required=True)
  299. g.add_argument('dump', nargs='?', help='RAM dump obtained from D2 g-code')
  300. g.add_argument('--map', action='store_true', help='dump global memory map')
  301. args = ap.parse_args()
  302. grefs = get_elf_globals(args.elf, expand_structs=not args.no_expand_structs)
  303. grefs = list(sorted(grefs, key=lambda x: x.loc))
  304. if args.dump is None:
  305. print_map(grefs)
  306. else:
  307. addr, data = decode_dump(args.dump)
  308. annotate_refs(grefs, addr, data,
  309. width=args.name_width,
  310. gaps=not args.no_gaps,
  311. overlaps=args.overlaps)
  312. if __name__ == '__main__':
  313. exit(main())