DRA821U: Put the startup code into ddr does not work properly

Reality

Prodigy 50 points

Part Number: DRA821U

Put .bootCode and .startupCode section into ddr, they cannot work normally.

The code enters an abnormal state,maybe Prefetch Abort exception.

What are the reasons for this?

over 5 years ago

0 Reality over 5 years ago

Prodigy 50 points

.bootCode and .startupCode at address 0x8008A000

0 Karthik Ramanan over 4 years ago in reply to Reality

TI__Guru** 113810 points

Hi,

Please provide the following inputs:

Can you please describe your boot flow/sequence?
Which core are you trying to put this startup code in DDR and it is causing this exception?
And also specify whether you are trying this on the EVM and provide details of the SDK.

Regards

Karthik

0 Reality over 4 years ago in reply to Karthik Ramanan

Prodigy 50 points

Can you please describe your boot flow/sequence?

used no boot mode.

2.Which core are you trying to put this startup code in DDR and it is causing this exception?

MCU1_0

3. And also specify whether you are trying this on the EVM and provide details of the SDK.

Same result on the EVM board，SDK Version 7.3.

I guess it may be a problem with cache or mpu permissions.

+1 Karan Saxena over 4 years ago in reply to Reality

TI__Guru* 78155 points

Hi,

Upon PORz, R5F's default MPU (memory protection unit) is not setup to have execute permissions for DDR. Till you do not run the MPU init function from the startup code, hence overriding the default MPU settings, you can not execute code from DDR.

Default R5F MPU regions can be seen in R5 TRM - https://developer.arm.com/documentation/ddi0460/d/Memory-Protection-Unit/About-the-MPU . You will see execute never for address > 0x80000000.

Regards

Karan

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DRA821U: Put the startup code into ddr does not work properly