Identify device when booting in Serial Downloader mode

NXP i.MX8M Plus
1

Hi,

We have a huge number of devices and we need to register them automatically in an internal inventory. We’re trying to unequivocally identify each device before flashing it, as a preliminary step in the flashing procedure. Hence, the device is booted in Serial Downloader mode.

Then, in that boot mode we need to gather at least this information:

  • MAC
  • Module Serial Number, or any other identifier that never changes and is unique for each device.

How could we get this information? We will need to include this gathering to a script to be run automatically.

Thanks in advance,
Jose

2 Likes
2

Are your devices being fused with the MAC address at the factory, or is the eeprom being programmed with TLV factory data?

3

Currently, we’ve received a first batch programmed with TLV factory data, but we expect to receive the big batch fused. What would be the process to obtain that information in each case?

4

In the case of MAC, we see it by:

  • booting from eMMC
  • connecting serial port with Minicom
  • running ‘net list’

When booting in Serial Downloader mode, we’ve defined a custom ‘.lst’ file derived from the original ‘emmc_burn_all.lst’ containing 'FB: ucmd net list ’ and executed the ‘uuu’. However:

  • The output is not seen in stdout
  • We see the output in the Minicom console, but, the MAC that appears there is clearly wrong as it reports that:

eth1 : ethernet@30bf0000 00:00:00:00:00:00 active

How can we see and gather the output of uuu through the USB port, and get the proper value?

5

Regarding the command ‘printenv’. Adding it to the ‘.lst’ file and running it with ‘uuu’ in Serial Downloader mode reports different variables than running it directly from u-boot when booting from eMMC.

Booting from eMMC:

eth1addr=6a:29:f9:3e:a9:3c
ethact=ethernet@30bf0000
ethprime=eth1

Booting in Serial Downloader mode, the unique variable referring to the ethernet is:

ethprime=eth1

6

Surfing in the doc it says that MAC can be programmed in the TLV (source):

"The EEPROM can be programmed from the U-Boot cli accordingly by the following commands:
…
tlv_eeprom set 0x24 '12:34:56:78:9a:bc'

However, when I try to run tlv_eeprom in u-boot, well in the eMMC or in the uSD, it reports that:

Unknown command ‘tlv_eeprom’ - try ‘help’

And the help command shows no command related with tlv

Also, in that doc (source), it points that there are some variables programmed in TLV such as:

TLV_CODE_SERIAL_NUMBER (mandatory)
TLV_CODE_DEVICE_VERSION (mandatory) Board Revision, incremented when parts or layout changes; MAJOR.MINOR revisions are encoded by storing MAJOR in the four most significant bits, MINOR in the four least significant bits.

How can I read that values? They are not in printenv.

Thanks in advance

7

Please @jnettlet , could you provide us some light in this topic?