MCU-PLUS-SDK-AM64X: Multiple RPMessage Endpoints all mapped to the same object in localEndPtObj[]

Hiroki Hoshina

Part Number: MCU-PLUS-SDK-AM64X

I am using SDK 11.00.00.15, and I am working with the RPMessage implementation included in TI IPC.
I am trying to register multiple local endpoints with my own callback (OnRPMessage) across a range of endpoint IDs.

However, I am facing the following problem:
Even though I loop through multiple endpoint IDs, all entries in gIpcRpmsgCtrl.localEndPtObj[] end up pointing to the same RPMessage object.
As a result, the endpoints do not behave independently.

What I am doing:

for (int i = 0 ; i < 7 ; i++)
{
    RPMessage_CreateParams_init(&createPrms);
    createPrms.localEndPt = i;
    createPrms.recvCallback = RPMessage_User_Callback_Handler;
    status = RPMessage_construct(&gIpcRpmsgCtrl.controlEndPtObj, &createPrms);
    if (SystemP_SUCCESS != status)
    {
        break;
    }
}

Here, controlEndPtObj is the only RPMessage_Object defined in gIpcRpmsg_Ctrl in the TI SDK.

Because I pass the same object (controlEndPtObj) every time:

RPMessage_construct() stores that same pointer in localEndPtObj[i]
therefore all entries end up identical:

localEndPtObj[4] → &controlEndPtObj
localEndPtObj[5] → &controlEndPtObj
localEndPtObj[6] → &controlEndPtObj
...

Thus multiple endpoints cannot operate independently.

Question:

Is RPMessage designed such that each local endpoint must have its own dedicated RPMessage_Object instance?
If yes:

1. Is it correct that I should allocate an array of RPMessage_Object for user-defined endpoints?
2. Is there any official or recommended way to create multiple endpoints with callbacks?
3. Is it acceptable to extend IpcRpmsg_Ctrl, like:

CRPMessage_Object userEndPtObj[RPMESSAGE_MAX_LOCAL_ENDPT];

and pass &userEndPtObj[i] to RPMessage_construct()?
4. Or does TI recommend a different design for handling multiple custom endpoints?

Best regards,
Hiroki Hoshina

3 months ago

+1 Tushar Thakur 3 months ago

TI__Guru 62298 points

Hi,

I have checked the driver code and yes the understanding is correct here. The gIpcRpmsgCtrl object have only one controlEndPtObj object which is overridden every time if same RPMessage_Object is used as the RPMessage_Object's localEndPtObj points to this object.

Hiroki Hoshina said:
1. Is it correct that I should allocate an array of RPMessage_Object for user-defined endpoints?

Yes, You can create an array of RPMessage_Object to separately store handlers for each endpoint.

Hiroki Hoshina said:
2. Is there any official or recommended way to create multiple endpoints with callbacks?

Hiroki Hoshina said:
4. Or does TI recommend a different design for handling multiple custom endpoints?

You can refer to the rpmsg_echo example provided in the SDK. We have created different RPMessage_Object for different endpoints.

Hiroki Hoshina said:
3. Is it acceptable to extend IpcRpmsg_Ctrl, like:

Yes, this should work. Let us know if you face any issues.

Regards,

Tushar

0 Hiroki Hoshina 3 months ago in reply to Tushar Thakur

Prodigy 110 points

Hi Tushar-san,

Thank you very much for reviewing code.

In particular, the note from the rpmsg_echo example:

/* RPMessage_Object MUST be global or static */ static RPMessage_Object gRecvMsgObject;

was very informative and helped me understand the issue clearly.

I really appreciate your support and the time you spent looking into the details.

Best regards,
Hiroki Hoshina

0 Tushar Thakur 3 months ago in reply to Hiroki Hoshina

TI__Guru 62298 points

Hiroki Hoshina said:
I really appreciate your support and the time you spent looking into the details.

Glad to know the above. Thank you for your kind words.

Regards,

Tushar

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MCU-PLUS-SDK-AM64X: Multiple RPMessage Endpoints all mapped to the same object in localEndPtObj[]