AM4379: PROCESSOR-SDK-AM437X

Hi Matt,

our secure boot support expert is out of the office at the moment. I suppose this secure boot package you got doesn't include any C source code for the key writer tool part of the image file it creates, so that you can change/update the project accordingly?

Depending on what you are trying to do and how urgent this is another option could be (temporarily or permanently) modifying your board to use UART0 for this purpose.

Regards, Andreas

H/W board's change for UART0 is not available. Could you please let me know when TI can provide OTP writer with UART3? Thanks

I did some quick search here and it looks like the OTP writer is only being provided as a pre-compiled binary to our customers. So you have no way to modify the UART interface yourself it seems. With that our best bet is to wait for our security expert to return to the office in about 2 weeks to see if a custom binary can be provided. Unfortunately it's not something that somebody else can easily pick up due to the sensitivity and complexity of the software and related development and distribution flows.

Regards, Andreas

I hope TI would find any workaround to shorten customer's waiting. Please keep me posted.

Thanks for your update.

I'm checking internally what is even possible here in terms of customization.

Out of curiosity, why wasn't the board designed such that UART0 is accessible/usable?

Regards, Andreas

Unfortunately, UART0 has been pre-assigned to communicate with other system, so that UART3 is used for TI serial console. 

Thanks 

Matt Lee said:

Unfortunately, UART0 has been pre-assigned to communicate wit

So you have no way getting to the signals, at least temporarily? Through a PCB connector? Or test points? You'd only need that access during the key programming process.

Regards, Andreas

Hi Matt,

it looked like there was a duplicated response from you and once I deleted the duplicate the original one disappeared as well. Not sure if that was a glitch in the system or what happened there but sorry about that. Can you please re-post your additional questions here. Also please note Hong is technically still out of the office until early next week so responses might still be slightly delayed.

Regards, Andreas

Please find the inline reply.

1/. As recommended by Andreas, is it feasible to have temparory testing fixture to make UART0 available?

[Matt] We need to change H/W design for changing UART3 to UART0.
2/. use "otp_cfg_prod.txt" to configure "DEBUG_FLAG = 0x00000000" to make release run (no user input) as noted.
# debug_flag:
# a. == 0xFFFFFFFF, debug run (user input)
# b. == 0x00000000, release run (no user input)

[Matt] When I use "otp_cfg_prod.txt" for no user input, is there any way for me to check if OTP programming is done (or OTP was done before)? I think the user input option (DEBUG_FLAG = 0xFFFFFFFF) looks good for checking the current status of OTP programming on H/W boards.

Thanks

In case of "DEBUG_FLAG = 0x00000000" to make release run,
a/. user interective input from serial port is not required.
b/. but the OTP programming status is still output from UART0, one option for your case is running image signed with your key set after key programming.
Best,
-Hong

Let me know whether TI has any technical issue or there is no resource available to release OTP image for uart3. If TI cannot release the OTP image for uart3, I will ask H/W team to change UART3 to UART0 for serial console. Thanks

Hi Matt,

Matt Lee said:

If TI cannot release the OTP image for uart3, I will ask H/W team to change UART3 to UART0 for serial console. Thank

If you really need to use the UART for operating the OTP KW package (and can't use the "silent" approach Hong suggested) then please make arrangements for said HW modifications. Customizing this tool is not something we can readily support due to effort and complex release flow. Then, it would need to be maintained as well.

Regards, Andreas