AM2732: I want to configure NOINIT Ram for few variables

shivang Joshi

Prodigy 10 points

Part Number: AM2732

Hello TI Team,

I am configuring NOINIT RAM by using pragma but variables are initialized after reset.

#pragma NOINIT(x)

#pragma location = 0x00147400 // memory address in RAM

uint32 x;

I have also tried changing linker file to add noinit section but its not working.

I have check on forum also but didnt worked https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1077304/tms570lc4357-no-init-memory-on-reset-for-storing-reset-information

Could you please provide support to configure noinit in our project.

8 months ago

0 Swargam Anil 8 months ago

TI__Guru 54798 points

Hello shivang Joshi,

I am routing your query to right expert, and you may get delayed replies as the expert is Out Of Office till this week.

Regards,

Anil.

0 Meet Thakar 8 months ago in reply to Swargam Anil

TI__Mastermind 23215 points

Hi Shivang,

Please refer to this: 2.7.3. Variable Attributes — TI Arm Clang Compiler Tools User's Guide

Best Regards,

Meet.

0 shivang Joshi 8 months ago in reply to Meet Thakar

Prodigy 10 points

Hi Meet,

I have already tried this approach, but its not working, Could you please let me know which RAM location i need to choose ? I have kept my variable in DSS_L3 location ? i also tried this location 0x100 as mentioned in the example.

Also do we need to configure MPU for that location ?

0 Meet Thakar 8 months ago in reply to shivang Joshi

TI__Mastermind 23215 points

Hi Shiavang,

shivang Joshi said:
have already tried this approach, but its not working

Could you elaborate the issue you are facing.

shivang Joshi said:
Could you please let me know which RAM location i need to choose ?

That depends upon your requirement, in my opinion, DSS_L3 should also be fine.

shivang Joshi said:
Also do we need to configure MPU for that location ?

You can configure the MPU for that region and see if that makes any difference.

0 shivang Joshi 8 months ago in reply to Meet Thakar

Prodigy 10 points

Hello Meet,

i have defined NOINIT RAM memory, under DSS_L3 section

Created section :

Now i have declared 2 variables xvar and yvar and i am placing my variables under that section(tried both section and location approach)

These variables are not retaining its value after system reset/ warm reset.

Both these approach are not working.

Also tried MPU configuration on top of this but not working.

Best Regards,
Shivang Joshi

0 Meet Thakar 8 months ago in reply to shivang Joshi

TI__Mastermind 23215 points

Hi Shivang,

Please share your generated map file for this.

Best Regards,

Meet.

0 shivang Joshi 8 months ago in reply to Meet Thakar

Prodigy 10 points

Hi Meet,

Could you please share your email id so that i can share it with secure file transfer link.

Best Regards,
Shivang Joshi

0 shivang Joshi 8 months ago in reply to shivang Joshi

Prodigy 10 points

Meanwhile attaching screenshot for your reference:

Variable :xvar

Variable: yvar

From the map file it seems it is correctly placed. i'll share you .map file over mail.

0 Meet Thakar 8 months ago in reply to shivang Joshi

TI__Mastermind 23215 points

I am assigning this thread to another expert, please wait for their response.

0 Ming Wei 8 months ago in reply to Meet Thakar

TI__Guru 57505 points

Hi Shivang,

Please refer to the following e2e thread:

(+) AM2732-Q1: AM2731 MSS L2 memory data lost directly after softreset - Harman Sitara MPU Forum - Harman Automotive - TI E2E support forums

Beat regards,

Ming

0 shivang Joshi 8 months ago in reply to Ming Wei

Prodigy 10 points

Hello Ming,

I am unable to access the above link,

Best Regards,
Shivang Joshi

0 Ming Wei 8 months ago in reply to shivang Joshi

TI__Guru 57505 points

Hi Shivang,

This post is in the Harman internal forum. If your colleagues have the access to the Harman internal forum, then you can ask them to help.

I post the conclusion here just in case:

------------

We have identified the place where the MSS_L2 got cleared by the RBL: StartMeminitTCMAAndL2().

As of DSS_L3, at least the RBL is not clearing it. In SBL, it got clear by the:

SOC_rcmStartMemInitDSSL3(SOC_RCM_MEMINIT_DSSL3_MEMBANK_ALL);

Make sure you are not calling it in your SBL.

-------------

Best regards,

Ming

0 shivang Joshi 8 months ago in reply to Ming Wei

Prodigy 10 points

Hello Ming,

We are calling this function in our SBL, but i want to understand if we will not call this then what will be the impact ? will it give ECC error ?

I tried commenting it but my boad is not booting,

Also SOC_rcmStartMemInitDSSL3(SOC_RCM_MEMINIT_DSSL3_MEMBANK_ALL);
in this API we are initializing all the DSSL3 banks, so can we exclude one bank from the initiallizing ? if yes how to identify bank address, and its size. As per manual DSS_L3 size is 3.5625 mb.

So 0x88147400 comes under which bank of DSS_L3 (A,B,C or D) ?

Best Regards,
Shivang Joshi

0 Ming Wei 8 months ago in reply to shivang Joshi

TI__Guru 57505 points

Hi Shivang,

Yes. The SOC_RCM_MEMINIT_DSSL3_MEMBANK_ALL is defined as below:

#define SOC_RCM_MEMINIT_DSSL3_MEMBANK_ALL (SOC_RCM_MEMINIT_DSSL3_MEMBANK_RAM0 | \
SOC_RCM_MEMINIT_DSSL3_MEMBANK_RAM1 | \
SOC_RCM_MEMINIT_DSSL3_MEMBANK_RAM2 | \
SOC_RCM_MEMINIT_DSSL3_MEMBANK_RAM3)

DSSL3_BANKA (RAM0) starts at 0x88000000 has size 1MB

DSSL3_BANKB (RAM1) starts at 0x88100000 has size 1MB

DSSL3_BANKA (RAM2) starts at 0x88200000 has size 1MB

DSSL3_BANKA (RAM3) starts at 0x88300000 has size 0.5625MB

So 0x88147400 comes under which bank of DSS_L3 BankB.

Best regards,

Ming

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AM2732: I want to configure NOINIT Ram for few variables