util/apcb/apcb_edit.py

   1 #!/usr/bin/env python3
   2
   3 # Script for editing APCB binaries, such as injecting SPDs and GPIO
   4 # configurations.
   5
   6 import sys
   7 import re
   8 import argparse
   9 from collections import namedtuple
  10 from struct import *
  11
  12 GPIO_MAGIC = bytes.fromhex('fadeddad' * 3)
  13 SPD_MAGIC = bytes.fromhex('f005ba110000')
  14 EMPTY_SPD = b'\x00' * 512
  15
  16 spd_ssp_struct_fmt = '??B?IIBBBxIIBBBx'
  17 spd_ssp_struct = namedtuple(
  18     'spd_ssp_struct', 'SpdValid, DimmPresent, \
  19                     PageAddress, NvDimmPresent, \
  20                     DramManufacturersIDCode, Address, \
  21                     SpdMuxPresent, MuxI2CAddress, MuxChannel, \
  22                     Technology, Package, SocketNumber, \
  23                     ChannelNumber, DimmNumber')
  24
  25
  26 def parseargs():
  27     parser = argparse.ArgumentParser(description='Inject SPDs and SPD GPIO \
  28                      selection pins into APCB binaries')
  29     parser.add_argument(
  30         'apcb_in',
  31         nargs='?',
  32         type=argparse.FileType('rb'),
  33         default=sys.stdin,
  34         help='APCB input file')
  35     parser.add_argument(
  36         'apcb_out',
  37         nargs='?',
  38         type=argparse.FileType('wb'),
  39         default=sys.stdout,
  40         help='APCB output file')
  41     parser.add_argument(
  42         '--spd_0_0',
  43         type=argparse.FileType('rb'),
  44         help='SPD input file for channel 0, dimm 0')
  45     parser.add_argument(
  46         '--spd_0_1',
  47         type=argparse.FileType('rb'),
  48         help='SPD input file for channel 0, dimm 1')
  49     parser.add_argument(
  50         '--spd_1_0',
  51         type=argparse.FileType('rb'),
  52         help='SPD input file for channel 1, dimm 0')
  53     parser.add_argument(
  54         '--spd_1_1',
  55         type=argparse.FileType('rb'),
  56         help='SPD input file for channel 1, dimm 1')
  57     parser.add_argument(
  58         '--hex',
  59         action='store_true',
  60         help='SPD input file is hex encoded, binary otherwise')
  61     parser.add_argument(
  62         '--strip_manufacturer_information',
  63         action='store_true',
  64         help='Strip all manufacturer information from SPD')
  65     parser.add_argument(
  66         '--board_id_gpio0',
  67         type=int,
  68         required=True,
  69         nargs=3,
  70         help='Board ID GPIO 0: NUMBER IO_MUX BANK_CTRL')
  71     parser.add_argument(
  72         '--board_id_gpio1',
  73         type=int,
  74         required=True,
  75         nargs=3,
  76         help='Board ID GPIO 1: NUMBER IO_MUX BANK_CTRL')
  77     parser.add_argument(
  78         '--board_id_gpio2',
  79         type=int,
  80         required=True,
  81         nargs=3,
  82         help='Board ID GPIO 2: NUMBER IO_MUX BANK_CTRL')
  83     parser.add_argument(
  84         '--board_id_gpio3',
  85         type=int,
  86         required=True,
  87         nargs=3,
  88         help='Board ID GPIO 3: NUMBER IO_MUX BANK_CTRL')
  89     return parser.parse_args()
  90
  91
  92 def chksum(data):
  93     sum = 0
  94     for b in data[:16] + data[17:]:
  95         sum = (sum + b) & 0xff
  96     return (0x100 - sum) & 0xff
  97
  98
  99 def inject(orig, insert, offset):
 100     return b''.join([orig[:offset], insert, orig[offset + len(insert):]])
 101
 102
 103 def main():
 104     args = parseargs()
 105
 106     print("Reading input APCB from %s" % (args.apcb_in.name))
 107
 108     apcb = args.apcb_in.read()
 109
 110     orig_apcb_len = len(apcb)
 111
 112     gpio_offset = apcb.find(GPIO_MAGIC)
 113     assert gpio_offset > 0, "GPIO magic number not found"
 114     print('GPIO magic number found at offset 0x%x' % gpio_offset)
 115     gpio_array = (args.board_id_gpio0 + args.board_id_gpio1 +
 116                   args.board_id_gpio2 + args.board_id_gpio3)
 117     print('Writing SPD GPIO array %s' % gpio_array)
 118     apcb = inject(apcb, pack('BBBBBBBBBBBB', *gpio_array), gpio_offset)
 119
 120     spd_offset = 0
 121     while True:
 122         spd_offset = apcb.find(SPD_MAGIC, spd_offset)
 123         if spd_offset < 0:
 124             break
 125
 126         spd_ssp_offset = spd_offset - calcsize(spd_ssp_struct_fmt)
 127         spd_ssp_bytes = apcb[spd_ssp_offset:spd_offset]
 128         spd_ssp = spd_ssp_struct._make(
 129             unpack(spd_ssp_struct_fmt, spd_ssp_bytes))
 130
 131         assert spd_ssp.DimmNumber >= 0 and spd_ssp.DimmNumber <= 1, \
 132                 "Unexpected dimm number found in APCB"
 133         assert spd_ssp.ChannelNumber >= 0 and spd_ssp.ChannelNumber <= 1, \
 134                 "Unexpected channel number found in APCB"
 135
 136         print("Found SPD magic number with channel %d and dimm %d "
 137               "at offset 0x%x" % (spd_ssp.ChannelNumber, spd_ssp.DimmNumber,
 138                                     spd_offset))
 139
 140         dimm_channel = (spd_ssp.ChannelNumber, spd_ssp.DimmNumber)
 141         spd = None
 142         if dimm_channel == (0, 0) and args.spd_0_0:
 143             spd = args.spd_0_0.read()
 144         elif dimm_channel == (0, 1) and args.spd_0_1:
 145             spd = args.spd_0_1.read()
 146         elif dimm_channel == (1, 0) and args.spd_1_0:
 147             spd = args.spd_1_0.read()
 148         elif dimm_channel == (1, 1) and args.spd_1_1:
 149             spd = args.spd_1_0.read()
 150
 151         if spd:
 152             if args.hex:
 153                 spd = spd.decode()
 154                 spd = re.sub(r'#.*', '', spd)
 155                 spd = re.sub(r'\s+', '', spd)
 156                 spd = bytes.fromhex(spd)
 157
 158             assert len(spd) == 512, \
 159                             "Expected SPD to be 512 bytes, got %d" % len(spd)
 160
 161             if args.strip_manufacturer_information:
 162                 print("Stripping manufacturer information from SPD")
 163                 spd = spd[0:320] + b'\x00'*64 + spd[320+64:]
 164
 165                 assert len(spd) == 512, \
 166                                 "Error while stripping SPD manufacurer information"
 167
 168             print("Enabling channel %d, dimm %d and injecting SPD" %
 169                   (spd_ssp.ChannelNumber, spd_ssp.DimmNumber))
 170             spd_ssp = spd_ssp._replace(SpdValid=True, DimmPresent=True)
 171
 172         else:
 173             print("Disabling channel %d, dimm %d and clearing SPD" %
 174                   (spd_ssp.ChannelNumber, spd_ssp.DimmNumber))
 175             spd_ssp = spd_ssp._replace(SpdValid=False, DimmPresent=False)
 176             spd = EMPTY_SPD
 177
 178         apcb = inject(apcb, pack(spd_ssp_struct_fmt, *spd_ssp), spd_ssp_offset)
 179         apcb = inject(apcb, spd, spd_offset)
 180
 181         spd_offset += 512
 182
 183     print("Fixing checksum and writing to %s" % (args.apcb_out.name))
 184
 185     apcb = inject(apcb, bytes([chksum(apcb)]), 16)
 186
 187     assert chksum(apcb) == apcb[16], "Checksum is invalid"
 188     assert orig_apcb_len == len(apcb), \
 189                 "The size of the APCB binary changed, this should not happen."
 190
 191     args.apcb_out.write(apcb)
 192
 193
 194 if __name__ == "__main__":
 195     main()