#!/usr/bin/env python3
##
## This file is part of the sigrok-util project.
##
## Copyright (C) 2013 Marcus Comstedt <marcus@mc.pp.se>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
import sys
import struct
import parseelf
class searcher:
def reset(this, offs=0):
if offs < 0 or offs > this.length:
raise Exception('Reset past end of section')
this.address = this.baseaddr + offs
this.offset = offs
def skip(this, cnt):
if this.offset + cnt > this.length:
raise Exception('Skip past end of section')
this.address += cnt
this.offset += cnt
def peek(this, cnt, offs=0):
if this.offset + offs + cnt > this.length:
raise Exception('Peek past end of section')
return this.data[this.offset + offs : this.offset + offs + cnt]
def look_for(this, needle):
pos = this.data.find(needle, this.offset)
if pos < 0:
raise Exception('Needle not found in haystack')
this.skip(pos - this.offset)
def look_for_either(this, needle1, needle2):
pos1 = this.data.find(needle1, this.offset)
pos2 = this.data.find(needle2, this.offset)
if pos1 < 0 and pos2 < 0:
raise Exception('Needle not found in haystack')
if pos1 < 0 or pos2 < pos1:
pos1 = pos2
this.skip(pos1 - this.offset)
def __init__(this, data, addr):
this.data = data
this.baseaddr = addr
this.length = len(data)
this.reset()
def search_plt_32(plt, addr):
plt.reset()
plt.look_for(struct.pack('<BBI', 0xff, 0x25, addr)) # jmp *addr32
return plt.address
def search_plt_64(plt, addr):
plt.reset()
while True:
plt.look_for(b'\xff\x25') # jmpq *offs32(%rip)
offs = struct.unpack('<i', plt.peek(4, 2))[0]
if plt.address + offs + 6 == addr:
return plt.address
plt.skip(2)
def find_hex_file_lines_constructor_32(text, hex_file_lines_got, got_plt):
while True:
text.look_for_either(b'\x8b\xbb', b'\x8b\xb3') # mov offs32(%ebx),{%edi,%esi}
offs = struct.unpack('<i', text.peek(4, 2))[0]
if got_plt + offs == hex_file_lines_got:
text.skip(6)
return
text.skip(2)
def find_hex_file_lines_constructor_64(text, hex_file_lines_got):
while True:
text.look_for(b'\x48\x8b\x2d') # mov offs32(%rip),%rbp
offs = struct.unpack('<i', text.peek(4, 3))[0]
if text.address + offs + 7 == hex_file_lines_got:
text.skip(7)
return
text.skip(3)
def parse_hex_file_lines_constructor_32(text, basic_string_plt, got_plt, lines):
text.skip(-5)
esi = (text.peek(1) == b'\xb3')
text.skip(5)
cnt = len(lines)
while cnt > 0:
if text.peek(2) == b'\x8d\x45': # lea offs8(%ebp),%eax
text.skip(3)
elif text.peek(2) == b'\x8d\x85': # lea offs32(%ebp),%eax
text.skip(6)
if text.peek(1) == (b'\xbf' if esi else b'\xbe'): # mov $imm32,%esi
text.skip(5)
elif text.peek(2) == (b'\x31\xff' if esi else b'\x31\xf6'): # xor %esi,%esi
text.skip(2)
if text.peek(4) == b'\x89\x44\x24\x08': # mov %eax,0x8(%esp)
text.skip(4)
if text.peek(2) == b'\x8d\x83': # lea offs32(%ebx),%eax
straddr = struct.unpack('<i', text.peek(4, 2))[0]
text.skip(6)
straddr += got_plt
else:
raise Exception('Expected lea offs32(%ebx),%eax @ ' +
('0x%x' % text.address))
if text.peek(4) == b'\x89\x44\x24\x04': # mov %eax,0x4(%esp)
text.skip(4)
if text.peek(3) == (b'\x89\x34\x24' if esi else b'\x89\x3c\x24'): # mov %edi,(%esp)
offs = 0
text.skip(3)
elif text.peek(2) == (b'\x8d\x46' if esi else b'\x8d\x47'): # lea offs8(%edi),%eax
offs = struct.unpack('<b', text.peek(1, 2))[0]
text.skip(3)
elif text.peek(2) == (b'\x8d\x86' if esi else b'\x8d\x87'): # lea offs32(%edi),%eax
offs = struct.unpack('<i', text.peek(4, 2))[0]
text.skip(6)
else:
raise Exception('Expected lea offs(%e'+('s' if esi else 'd')+'i),%eax @ ' +
('0x%x' % text.address))
if offs < 0 or offs > (len(lines) << 2) or (offs & 3) != 0:
raise Exception('Invalid offset %d' % offs)
index = offs >> 2
if lines[index] != 0:
raise Exception('Line %d filled multiple times' % index)
if text.peek(3) == b'\x89\x04\x24': # mov %eax,(%esp)
text.skip(3)
if text.peek(1) == b'\xe8': # call offs32
offs = struct.unpack('<i', text.peek(4, 1))[0]
text.skip(5)
if text.address + offs != basic_string_plt:
raise Exception('Expected call ZNSsC1EPKcRKSaIcE@plt @ ' +
('0x%x' % text.address))
else:
raise Exception('Expected call ZNSsC1EPKcRKSaIcE@plt @ ' +
('0x%x' % text.address))
if straddr == 0:
raise Exception('NULL pointer stored to index %d' % index)
lines[index] = straddr
cnt -= 1
def parse_hex_file_lines_constructor_64(text, basic_string_plt, lines):
cnt = len(lines)
while cnt > 0:
if text.peek(1) == b'\xbb': # mov $imm32,%ebx
text.skip(5)
elif text.peek(2) == b'\x31\xdb': # xor %ebx,%ebx
text.skip(2)
if text.peek(4) == b'\x48\x8d\x54\x24': # lea offs8(%rsp),%rdx
text.skip(5)
elif text.peek(4) == b'\x48\x8d\x94\x24': # lea offs32(%rsp),%rdx
text.skip(8)
if text.peek(3) == b'\x48\x8d\x35': # lea offs32(%rip),%rsi
straddr = struct.unpack('<i', text.peek(4, 3))[0]
text.skip(7)
straddr += text.address
else:
raise Exception('Expected lea offs(%rip),%rsi @ ' +
('0x%x' % text.address))
if text.peek(3) == b'\x48\x89\xef': # mov %rbp,%rdi
offs = 0
text.skip(3)
elif text.peek(3) == b'\x48\x8d\x7d': # lea offs8(%rbp),%rdi
offs = struct.unpack('<b', text.peek(1, 3))[0]
text.skip(4)
elif text.peek(3) == b'\x48\x8d\xbd': # lea offs32(%rbp),%rdi
offs = struct.unpack('<i', text.peek(4, 3))[0]
text.skip(7)
else:
raise Exception('Expected lea offs(%rbp),%rdi @ ' +
('0x%x' % text.address))
if text.peek(1) == b'\xbb': # mov $imm32,%ebx
text.skip(5)
elif text.peek(2) == b'\x31\xdb': # xor %ebx,%ebx
text.skip(2)
if offs < 0 or offs > (len(lines) << 3) or (offs & 7) != 0:
raise Exception('Invalid offset %d' % offs)
index = offs >> 3
if lines[index] != 0:
raise Exception('Line %d filled multiple times' % index)
if text.peek(1) == b'\xe8': # callq offs32
offs = struct.unpack('<i', text.peek(4, 1))[0]
text.skip(5)
if text.address + offs != basic_string_plt:
raise Exception('Expected callq ZNSsC1EPKcRKSaIcE@plt @ ' +
('0x%x' % text.address))
else:
raise Exception('Expected callq ZNSsC1EPKcRKSaIcE@plt @ ' +
('0x%x' % text.address))
if straddr == 0:
raise Exception('NULL pointer stored to index %d' % index)
lines[index] = straddr
cnt -= 1
def find_reloc(elf, symname):
for section, relocs in elf.relocs.items():
if 'symbols' in relocs and symname in relocs['symbols']:
symnum = relocs['symbols'][symname]['number']
for reloc in relocs['relocs']:
if reloc['r_sym'] == symnum:
return reloc
raise Exception('Unable to find a relocation against ' + symname)
def ihex_to_binary(lines):
chunks = {}
for line in lines:
if line[0] != ':':
raise Exception('ihex line does not start with ":"')
line = bytes.fromhex(line[1:])
if (sum(bytearray(line)) & 0xff) != 0:
raise Exception('Invalid checksum in ihex')
(byte_count, address, rectype) = struct.unpack('>BHB', line[:4])
(data, checksum) = struct.unpack('>%dsB' % (byte_count), line[4:])
if rectype == 1 and byte_count == 0:
pass
elif rectype != 0 or byte_count == 0:
raise Exception('Unexpected rectype %d with bytecount %d' %
(rectype, byte_count))
elif address in chunks:
raise Exception('Multiple ihex lines with address 0x%x' % address)
else:
chunks[address] = data
blob = b''
for address in sorted(iter(chunks)):
if address < len(blob):
raise Exception('Overlapping ihex chunks')
elif address > len(blob):
blob += b'\x00' * (address - len(blob))
blob += chunks[address]
return blob
def extract_fx2_firmware(elf, symname, filename):
blob = elf.load_symbol(elf.dynsym[symname + 'Count'])
count = struct.unpack('<I', blob)[0]
got_plt = elf.find_section('.got.plt')['sh_addr']
hex_file_lines_got = find_reloc(elf, symname)['r_offset']
basic_string_got = find_reloc(elf, '_ZNSsC1EPKcRKSaIcE')['r_offset']
pltsec = elf.find_section('.plt')
plt = searcher(elf.read_section(pltsec), pltsec['sh_addr'])
try:
if elf.elf_wordsize == 64:
basic_string_plt = search_plt_64(plt, basic_string_got)
else:
basic_string_plt = search_plt_32(plt, basic_string_got)
except:
raise Exception('Unable to find a PLT entry for _ZNSsC1EPKcRKSaIcE')
textsec = elf.find_section('.text')
text = searcher(elf.read_section(textsec), textsec['sh_addr'])
while True:
try:
if elf.elf_wordsize == 64:
find_hex_file_lines_constructor_64(text, hex_file_lines_got)
else:
find_hex_file_lines_constructor_32(text, hex_file_lines_got,
got_plt)
except:
raise Exception('Unable to find constructor for ' + symname)
oldoffs = text.offset
l = [0]*count
try:
if elf.elf_wordsize == 64:
parse_hex_file_lines_constructor_64(text, basic_string_plt, l)
else:
parse_hex_file_lines_constructor_32(text, basic_string_plt,
got_plt, l)
break
except KeyError:
text.reset(oldoffs)
rodatasec = elf.find_section('.rodata')
rodata = elf.read_section(rodatasec)
lo = rodatasec['sh_addr']
hi = lo + rodatasec['sh_size']
for i in range(count):
addr = l[i]
if addr < lo or addr >= hi:
raise Exception('Address 0x%x outside of .rodata section' % addr)
l[i] = elf.get_name(addr - lo, rodata)
blob = ihex_to_binary(l)
f = open(filename, 'wb')
f.write(blob)
f.close()
print("saved %d bytes to %s" % (len(blob), filename))
def extract_symbol(elf, symname, filename):
blob = elf.load_symbol(elf.dynsym[symname])
f = open(filename, 'wb')
f.write(blob)
f.close()
print("saved %d bytes to %s" % (len(blob), filename))
def extract_bitstream(elf, lv):
extract_symbol(elf, 'gLogic16Lv' + lv + 'CompressedBitstream',
'saleae-logic16-fpga-' + lv + '.bitstream')
def usage():
print("sigrok-fwextract-saleae-logic16 <programfile>")
sys.exit()
#
# main
#
if len(sys.argv) != 2:
usage()
try:
filename = sys.argv[1]
elf = parseelf.elf(filename)
if elf.ehdr['e_machine'] != 3 and elf.ehdr['e_machine'] != 62:
raise Exception('Unsupported e_machine')
extract_fx2_firmware(elf, 'gLogic16HexFileLines', 'saleae-logic16-fx2.fw')
extract_bitstream(elf, '18')
extract_bitstream(elf, '33')
except Exception as e:
print("Error: %s" % str(e))
