RT118x EdgeLock access to M7 DTCM

[NicholasWatt]

Hi there,

I'm running into an issue where the device faults when the EdgeLock Enclave attempts to read data from the CM7 TCM. All ELE functions which do not access device memory are working correctly, however ones that do cause a fault. My application has the TRDC configured and activated by a secure bootloader, and the application runs in the non-secure world on both the M33 and M7, where the M7 application needs access to the ELE generic crypto functions (hash etc.). 

Memory addresses are being correctly converted to their aliased values for the M7 calls to the APP S3MU, and everything works correctly when the data is located in OCRAM. This leads me to think that it is a TRDC configuration error, however I cannot find any documentation in the RM TRDC section relating to the ELE master. If I try to assign a MRC region to M7 aliased DTCM for domain 0 the ELE fails to release the APC. What configuration steps are required to ensure that the ELE can access the M7 DTCM?

Many thanks

[Kan_Li]

Hi @NicholasWatt ，

Did you check this with the sdk demo "evkmimxrt1180_ele_crypto_generic_hash_cm7"? The code runs on ITCM_M7 and access the data on DTCM_M7.  I just verified this on RT1180EVK but didn't find any issue. Please kindly clarify.

Have a great day,
Kan

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[NicholasWatt]

Hi @Kan_Li 

I haven't directly tried that example, however it does not configure the TRDC, so both cores will run in secure mode by default? My app puts the M7 into non-secure mode and limits the memory regions it can access before branching into the non-secure firmware on the M33.

I've verified that the TRDC2 MRC 2 Domain ID 0 configuration should allow full access to all M7 TCM (W0: 0x0, W1: 0xFFFFC001, GLBAC0: 0x7777), The M7 memory address is 0x20019174 and the converted alias address provided to the ELE over the APPS_S3MUA is 0x20419174, which is within the M7 DTCM aliased address range on the M33 memory map. M7 ITCM is disabled for my application. The device seems to fault silently as the secure hardfault IRQ on the M33 never gets called, and the SRC SRSR reports that the reset was due to the Edgelock reset input (0x80).

Edit: Just to add, the M7 aliased memory region is left as secure in the SAU.

Let me know if you need any more information.

Many thanks

[Kan_Li]

 Hi @NicholasWatt ,

Yes, the core runs in secure mode by default within the SDK demo, and please try with the default TRDC configuration from the sdk demo, if it makes any difference.

Have a great day,
Kan

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