1#!/usr/bin/env python3 2 3# Script for editing APCB binaries, such as injecting SPDs and GPIO 4# configurations. 5 6import sys 7import re 8import argparse 9from collections import namedtuple 10from struct import * 11 12GPIO_MAGIC = bytes.fromhex('fadeddad' * 3) 13SPD_MAGIC = bytes.fromhex('f005ba110000') 14EMPTY_SPD = b'\x00' * 512 15 16spd_ssp_struct_fmt = '??B?IIBBBxIIBBBx' 17spd_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 26def 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 92def 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 99def inject(orig, insert, offset): 100 return b''.join([orig[:offset], insert, orig[offset + len(insert):]]) 101 102 103def 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 194if __name__ == "__main__": 195 main() 196