PNOR info dumping script (dumps partition table of OpenPOWER PNOR firmware images)

pnor-info.py

#!/usr/bin/env python3
import sys, struct, io

def read_hdr(f):
  d = f.read(12*4)
  dMagic = d[0:4]
  magic, version, size, entrySize, entryCount, blockSize, blockCount, resv0, resv1, resv2, resv3, checksum = struct.unpack('>' + 'I'*12, d)
  print('''
PNOR Header
  Magic:        {magic:#010x} ({dMagic})
  Version:      {version:10}
  Size:         {size:10}
  Entry Size:   {entrySize:10}
  Entry Count:  {entryCount:10}
  Block Size:   {blockSize:10}
  Block Count:  {blockCount:10}
  Reserved:     {resv0:#010x} {resv1:#010x} {resv2:#010x} {resv3:#010x}
  Checksum:     {checksum:#x}'''.format(**locals()))

  return locals()

def print_legend():
  print('''
Name              Base        Size        PID         ID          Type        Flags
                    Reserved                                                    Checksum
                    User
--------------------------------------------------------------------------------------------''')

units = ['  B', 'KiB', 'MiB', 'GiB']

def niceSize(sz):
  i = 0
  u = '  B'
  while sz >= 1024:
    i = i+1
    u = units[i]
    sz = sz//1024
  return '{0:9} {1}'.format(sz, u)

types={1:'DATA',2:'LOGICAL',3:'PARTITION'}

last_end = None

def read_item(f, hdr):
  global last_end

  d = f.read(hdr['entrySize'])
  assert len(d) == hdr['entrySize']
  blockSize = hdr['blockSize']

  dName, d = d[0:16], d[16:]
  dName = dName.rstrip(b'\x00').decode('ascii')
  x = struct.unpack('>'+'I'*28, d[0:28*4])
  base, size, pid, id, type, flags, actual, resv0, resv1, resv2, resv3 = x[0:11]
  d = d[11:]
  user = struct.unpack('>'+'I'*16, d[0:16*4])
  (cksum,) = struct.unpack('>I', d[16*4:16*4+4])

  if base > last_end:
    print('  (gap: {0} blocks)'.format(base-last_end))

  flagdec = ''
  if (flags & 0x01) != 0:
    flagdec += ' PROTECTED'
  if (flags & 0x02) != 0:
    flagdec += ' U_BOOT_ENV'
  print('{dName:16}  {base:#010x}  {size:#010x}  {pid:#010x}  {id:#010x}  {type:#010x}  {flags:#010x} {flagdec}'.format(**locals()))
  print('                    r {resv0:#010x}  {resv1:#010x}  {resv2:#010x}  {resv3:#010x}       ck={cksum:#010x}'.format(**locals()))
  i = 0
  while len(user) > 0:
    ex = ''
    if i == 0:
      ex = '  size {0}'.format(niceSize(size*blockSize))
    elif i == 1:
      ex = '  type {0:>13}'.format(types.get(type, str(type)))
    elif i == 2:
      ex = '  -s {0:#x} -n {1:#x}'.format(base*blockSize,size*blockSize)
    i = i+1
    print('                    u {0:#010x}  {1:#010x}  {2:#010x}  {3:#010x}{4}'.format(user[0],user[1],user[2],user[3],ex))
    user = user[4:]

  last_end = base+size

def run():
  global last_end
  with open('zaius.pnor', 'rb') as f:
    hdr = read_hdr(f)
    print_legend()

    last_end = (12*4+hdr['entrySize']*hdr['entryCount']+hdr['blockSize'])//hdr['blockSize']
    for i in range(hdr['entryCount']):
      read_item(f, hdr)

  return 0

if __name__ == '__main__':
  sys.exit(run())