RT1170: Debugging large SRAM Code (J-Link Script Question)

[lsrbigfoot]

I am currently using IAR EWARM for debugging ITCM code >64 KB on an i.MX RT1170 MCU.

One common observation from debug log I observe is the following after JLink loads the code into ITCM:

J-Link script: 0x5AA60FF0 has been written to address 0xFFFC

Is there a reason for the above action?
Is this associated with a J-Link script or something that is internal to the J-Link driver?

If I do something as simple as "Attach to Running Target" or Debug Reset (after pausing code) the above message displays in debug log.

With text region starting at 0x400 (m_text_start) and ending at 0x3FFFF (m_text_end), there easily can be a scenario where the above action results in text region being overwritten at address 0xFFFC by the JLink during debug, if the ITCM code allocation exceeds ~64 KB. 

I worked around this be making m_text_start 0x10000 instead of 0x400 avoiding accesses to address 0xFFFC by J-Link.

If feasible, is there a way for JLink to write 0x5aa60ff0 somewhere else (other than 0xFFFC) during ITCM debug?

[lsrbigfoot]

Thanks Diego!

Knowing that I was evaluating RT-UFL, your response answered my question perfectly.

[diego_charles · Accepted solution]

Hi @lsrbigfoot 

Many thanks for your patience.

Yes, it is related to the jlinkscript. 

Please refer to https://blog.csdn.net/Henjay724/article/details/118042904 This post talks about the 0x5AA60FF magic number, or identification number. Please translate it to English and check the 2 Solve the identification problem caused by non-overlapping ROM support. This is user by the i.MX RT UFL project. It is  basically a number to identify the i.MX RT117x. I consider that you may customize the RTL UFL project and see, if possible, change the address for this number. 

I hope this could help you. 

Diego