# Identify device when booting in Serial Downloader mode **URL:** \ **Category:** NXP i.MX8M Plus\ **Tags:** iMX8M-plus\ **Created:** [April 25, 2023, 3:47pm UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633 "2023-04-25T15:47:53Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![jetxeberria](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jetxeberria](https://community.solid-run.com/u/jetxeberria)\ **Post date:** [April 25, 2023, 3:47pm UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/1 "2023-04-25T15:47:53Z")
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 ---
**Author:** ![jnettlet](https://dub1.discourse-cdn.com/flex005/user_avatar/community.solid-run.com/jnettlet/32/62_2.png) [@jnettlet](https://community.solid-run.com/u/jnettlet)\ **Post date:** [April 26, 2023, 7:07am UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/2 "2023-04-26T07:07:10Z")
Are your devices being fused with the MAC address at the factory, or is the eeprom being programmed with TLV factory data? ---
**Author:** ![jetxeberria](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jetxeberria](https://community.solid-run.com/u/jetxeberria)\ **Post date:** [April 26, 2023, 7:53am UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/3 "2023-04-26T07:53:00Z")
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? ---
**Author:** ![jetxeberria](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jetxeberria](https://community.solid-run.com/u/jetxeberria)\ **Post date:** [April 26, 2023, 10:59am UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/4 "2023-04-26T10:59:35Z")
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? ---
**Author:** ![jetxeberria](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jetxeberria](https://community.solid-run.com/u/jetxeberria)\ **Post date:** [April 26, 2023, 11:51am UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/5 "2023-04-26T11:51:08Z")
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 ---
**Author:** ![jetxeberria](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jetxeberria](https://community.solid-run.com/u/jetxeberria)\ **Post date:** [April 27, 2023, 9:02am UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/6 "2023-04-27T09:02:33Z")
Surfing in the doc it says that MAC can be programmed in the TLV ([source](https://solidrun.atlassian.net/wiki/spaces/developer/pages/344883516/iMX8MP+EEPROM+Programming+-+TLV#Programming-from-U-Boot.1)): > "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](https://solidrun.atlassian.net/wiki/spaces/developer/pages/344883516/iMX8MP+EEPROM+Programming+-+TLV#SoM)), it points that there are some variables programmed in TLV such as: ```auto 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 ---
**Author:** ![jetxeberria](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jetxeberria](https://community.solid-run.com/u/jetxeberria)\ **Post date:** [May 2, 2023, 8:49am UTC](https://community.solid-run.com/t/identify-device-when-booting-in-serial-downloader-mode/633/7 "2023-05-02T08:49:22Z")
Please @jnettlet , could you provide us some light in this topic?