Using Flash API for 28035 with CSM enabled

Oleg Gladyshev

Other Parts Discussed in Thread: CONTROLSUITE

Hi all!

I need to use Flash API in my project to update internal firmware. Of course I will use CSM to protect my code. But when I try to erase some sectors (not the SECTORA) from the program I get Flash api error #10 STATUS_FAIL_CSM_LOCKED

I can unprotect the device during flash operation using CSMSCR register (and this works fine) but I don't want to do this because it is very insecure.

I use Flash API from Control Suite (libs/utilities/flash_api/2803x/v100). On this forum I found information that this error can occur when Flash API code being executed from insecure memory (M0 for example). But the API for 28035 executed from Boot ROM. The library doesn't include real code now which could be copied into desired RAM area. As I know I can't copy API code into RAM besause it was statically linked to be executed from the dedicated boot ROM.

So my general question is how can I flash some sectors of 28035 device without unlocking the chip during this operation?

over 10 years ago

0 Gautam Iyer over 10 years ago

Guru 192875 points

Hi Oleg,

Oleg Gladyshev said:
So my general question is how can I flash some sectors of 28035 device without unlocking the chip during this operation?

Are these sectors in locked state (that you need to flash)?

Also, do refer this link:

Regards,

Gautam

0 Oleg Gladyshev over 10 years ago in reply to Gautam Iyer

Prodigy 100 points

Gautam,
thank you for your reply.
I'll try to explain little more.
I have a basic firmware upgrade tool located in sector A. Also there is a CMS password stored in the A sector.
This tool must rewrite any other flash sectors by itself using Flash API. The problem occured when I try to erase any of B-H sectors calling Flash_Erase() routine. The routine returns #10 error which says that flash api code executed from insecure code area while chip is secured now.
If I call CSM_Unlock() before erasing all works fine but I don't want to unsecure chip every time I upgrade firmware in sectors B-H.

0 Gautam Iyer over 10 years ago in reply to Oleg Gladyshev

Guru 192875 points

Very clear now, Oleg. I'm not sure this is possible as unlocking is a must in this case. Let me call in Manoj Santha Mohan here to shed some more light.

Regards,
Gautam

0 Manoj Santha Mohan over 10 years ago in reply to Gautam Iyer

TI__Guru 55700 points

Oleg,

If you want to use the flash API available in BOOT ROM, you need to unlock the CSM before proceeding with erasing the flash sectors.

If you don't want to unsecure the device, you need to embedded Flash API in flash and then copy the API functions to secure RAM and execute from there. Since, you are executing flash erase operation from secure memory it will allow you to perform flash erase operation.

Regards,
Manoj

0 Oleg Gladyshev over 10 years ago in reply to Manoj Santha Mohan

Prodigy 100 points

Manoj, thank you very much. Do you know where can I get a Flash API library for 28035 device to embed it into the flash? The only library I found in the control suite doesn't contain any flashing code - just declarations for the functions stored in boot ROM.

0 Manoj Santha Mohan over 10 years ago in reply to Oleg Gladyshev

TI__Guru 55700 points

Oleg,

Please find them in the below path:-

Path: controlSUITE\libs\utilities\flash_api\2803x\v100a\lib

Filename: Flash2803x_API_V100.lib

Regards,
Manoj

0 Oleg Gladyshev over 10 years ago in reply to Manoj Santha Mohan

Prodigy 100 points

Thank you very much!

0 Giannis Roussos over 8 years ago in reply to Oleg Gladyshev

Expert 2290 points

Hello,

I want to use FlashAPI to modify ( erase - and write) the contents of one Flash sector (not sector A) containing configuration parameters for my application. The configuration parameters dont need to be secured but I want to enable CSM to protect my code.

I have found the FlashAPI full library so that, like Oleg, I can embed the FlashAPI functions in my code in Flash, but I would like to ask if it is necessary to copy the FlashAPI functions to RAM.

0 Vivek Singh over 8 years ago in reply to Giannis Roussos

TI__Guru** 115881 points

As mentioned by Manoj in ealier post -

If you don't want to unsecure the device, you need to embedded Flash API in flash and then copy the API functions to secure RAM and execute from there. Since, you are executing flash erase operation from secure memory it will allow you to perform flash erase operation.

You need to copy the API into RAM and then execute from there.

Vivek Singh

0 Giannis Roussos over 8 years ago in reply to Vivek Singh

Expert 2290 points

Thank you Vivek

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Using Flash API for 28035 with CSM enabled