TMS320F28377S: 28377S - How to lock the flash as Read only for 1 sector after booting?

Rio Chan

Genius 14885 points

Part Number: TMS320F28377S
Other Parts Discussed in Thread: UNIFLASH, SYSCONFIG

Champs:

On 28377S, how to lock the flash after booting / calibration data write?

I mean:

Step1: Booting.

Step2: Write cali data onto Falsh.

Step3: Lock the Cali data on the Flash as read only.

How to perform the Step3 in the code and how to perform step3 by uniflash.

Any example doc?

BR Rio

over 1 year ago

0 Luke Jones over 1 year ago

TI__Mastermind 27720 points

Hi Rio,

Are you concerned with your code accidentally overwriting a portion of memory in flash that has already been programmed with your calibration data? To reprogram the flash you must first erase the corresponding flash sector, so it's unlikely/impossible for your code to do this by mistake. Or are you concerned about a hacker modifying the calibration data somehow?

What is your motivation for wanting the calibration data to be read only?

Thank you,

Luke

0 Rio Chan over 1 year ago in reply to Luke Jones

TI__Genius 14885 points

Hi Luke:

1. Customer's motivation is to lock the Calibration section of the flash after he perform the calibration data wrote.

And he hopes no one can over-write it.

2. Do we have the example code of teaching him how to do this?

Thanks.

BR Rio.

0 Luke Jones over 1 year ago in reply to Rio Chan

TI__Mastermind 27720 points

Hi Rio,

I understand the customer wants to make sure the flash does not get overwritten. My question is what scenario are they worried about that could overwrite their calibration data?

If they're concerned about a hacker attempting to modify the data, they should use DCSM to secure the flash. We have video explanations of the DCSM module on ti.com as well a guide on using the SysConfig DCSM tool that you may find helpful.

If they're concerned about their own code modifying the flash, this should not be a concern for them, since they must erase the entire flash sector where their calibration data is stored using the flash API before being able to write new calibration data.

There is unused USER OTP in the DCSM USER OTP section of memory. If the customer is not using DCSM, they can write to any region of memory after the first zone select block in either of the two zones, but they would need to make sure they do not write in the zone header or first zone select block in either of the two zones. This is the only region of memory that is truly one-time programmable that would not corrupt important settings for security or boot.

Thank you,

Luke

0 Rio Chan over 1 year ago in reply to Luke Jones

TI__Genius 14885 points

Hi Luke:

Their concerned 2 things:

A. Hacker to modify the flash.

B. They worried the ESI surge shock voltage to damage the flash contain, so, they are testing if the Flash lock will be helpful to avoid the ESI.

--> have video explanations of the DCSM module on ti.com as well a guide on using the SysConfig DCSM tool that you may find helpful.

please guide us where to get this how-to-do.

Thanks.

BR Rio

0 Luke Jones over 1 year ago in reply to Rio Chan

TI__Mastermind 27720 points

Hi Rio,

The video series can be found here:

https://www.ti.com/video/series/C2000-dual-code-security-module.html

Thank you,

Luke

0 Rio Chan over 1 year ago in reply to Luke Jones

TI__Genius 14885 points

Hi Luke:

The #41 + #42 in the below link is the suitable answer I need, right?

Please confirm.

THanks.

BR Rio

https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/951668/faq-faq-on-flash-api-usage-for-c2000-devices

0 Luke Jones over 1 year ago in reply to Rio Chan

TI__Mastermind 27720 points

Hi Rio,

I suggest programming your values in a specific flash sector and protecting that flash sector using DCSM instead of programming your calibration values in USER OTP. Note that you would need a function in secure memory to read back these values. The DCSM Security Tool user's guide is a helpful resource for enabling this in SysConfig:

https://www.ti.com/lit/an/spracp8a/spracp8a.pdf?ts=1713459207448&ref_url=https%253A%252F%252Fwww.google.com%252F

Thank you,

Luke

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TMS320F28377S: 28377S - How to lock the flash as Read only for 1 sector after booting?