GM MDI serial number: How to get new serial

Here are some great tips and guides of GM MDI clone serial number update from HMM Forum，Collected by OBDexpress.co.uk

The GM MDI serial number is in the 16mb on board flash memory – the intel chip on the computer sub-board.

You can get u-boot access by making up a serial cable. Signals are available on the 8 pin mini din on the outside of the MDI case. pin 1 goes to PC TX (MDI

RX), pin 2 goes to PC RX (MDI TX). Pin 3 goes to ground. Then when you boot:

Quote:U-Boot 1.1.4 (Dec 21 2007 – 12:11:55) ETAS VCI
(r13006)

U-Boot code: A3F00000 -> A3F218F0 BSS: -> A3F27524

RAM Configuration: TRITON 270 II

Bank #0: a0000000 64 MB

Bank #1: a4000000 64 MB

HW Configuration: (0x207) MDI VCI with SMSC9116

Found P30 Flash, unlocking all blocks: 130

Flash: 16 MB

In: serial

Out: serial

Err: serial

Hit any key to stop autoboot: 0

$ help

? – alias for ‘help’

askenv – get environment variables from stdin

autoscr – run script from memory

base – print or set address offset

bdinfo – print Board Info structure

boot – boot default, i.e., run ‘bootcmd’

bootd – boot default, i.e., run ‘bootcmd’

bootm – boot application image from memory

bootp – boot image via network using BootP/TFTP protocol

cmp – memory compare

coninfo – print console devices and information

cp – memory copy

crc32 – checksum calculation

dhcp – invoke DHCP client to obtain IP/boot params

echo – echo args to console

erase – erase FLASH memory

exit – exit script

flinfo – print FLASH memory information

flock – physical lock of Strataflash

funlock – physical unlock of Strataflash

go – start application at address ‘addr’

help – print online help

iminfo – print header information for application image

imls – list all images found in flash

increnv – increment environment variables

itest – return true/false on integer compare

loadb – load binary file over serial line (kermit mode)

loads – load S-Record file over serial line

loop – infinite loop on address range

macaddr – display or store MAC address in Strataflash

mapadd – add a memory map item

mapdel – delete a memory map item

mapinfo – display the memory map information

md – memory display

mm – memory modify (auto-incrementing)

mmcinfo – get info on mmc(sd) card

mtest – simple RAM test

mw – memory write (fill)

nfs – boot image via network using NFS protocol

nm – memory modify (constant address)

ping – send ICMP ECHO_REQUEST to network host

pinit – PCMCIA sub-system

printenv- print environment variables

protect – enable or disable FLASH write protection

rarpboot- boot image via network using RARP/TFTP protocol

reset – Perform RESET of the CPU

run – run commands in an environment variable

saveenv – save environment variables to persistent storage

serialnum – display or store serial number in Strataflash

setenv – set environment variables

sleep – delay execution for some time

test – minimal test like /bin/sh

tftpboot- boot image via network using TFTP protocol

version – print monitor version


The problem is the serial number and MAC flash partitions are misaligned from
the flash erase block boundaries, which forces them to mount read only. Because
of this the update commands don’t work