AM5728: Starting/stopping a C66x DSP program under Linux

Jan-Marc Stranz

Part Number: AM5728

One of our requirements for a project is to run different DSP programs on the C66x DSP depending on the configuration.

The MPU subsystem (2x Arm Cortex-A15) is running Linux.
A Linux userspace application should copy the corresponding DSP Program (precompiled binary file) into the memory area for the DSP and then start (and later stop) the DSP.

How can this be implemented?
Is there an example in PROCESSOR-SDK-LINUX-AM57X or an application note?

The SoC AM5728 has 2 C66x DSP cores.
Is it possible to run 2 different programs on the two DSP cores?

Jan.

over 2 years ago

0 Stanley Liu over 2 years ago

TI__Guru 50045 points

Please review the IPC documentation as starting point.

https://software-dl.ti.com/processor-sdk-linux/esd/AM57X/08_02_01_00/exports/docs/linux/Foundational_Components_IPC.html

0 Jan-Marc Stranz over 2 years ago in reply to Stanley Liu

Intellectual 330 points

Vielen Dank für den Hinweis auf den Link.

Auch nach Lesen des Kapitels "IPC on AM57xx" ist für mich das IPC System leider immer noch nicht verständlich.

Ich kann zwar die dort beschriebenen Schritte mit den Beispielprogrammen ausführen, jedoch kenne ich die grundlegende Funktionsweise des remoteproc/rpmsg Treibers dannach immer noch nicht!

- Wie gelangt das auf dem DSP Kern auszuführende Programm tatsächlich?
- Wie bestimme ich die Startadresse und Größe für das auszuführende Programm?
- Wie kann ich mit dem auf dem DSP ausgeführten Programm kommunizieren und Daten austauschen?

Is there possibly a basic introduction or tutorial in the topic "TI IPC"?

0 Jan-Marc Stranz over 2 years ago in reply to Jan-Marc Stranz

Intellectual 330 points

Thank you for pointing out the link.

Even after reading the chapter "IPC on AM57xx" the IPC system is unfortunately still not understandable for me.

I can execute the steps described there with the example programs, however, I know the basic operation of the remoteproc/rpmsg driver then still not!

- How does the program to be executed on the DSP core actually get there?
- How do I determine the start address and size for the program to run?
- How can I communicate and exchange data with the program running on the DSP?

Is there possibly a basic introduction or tutorial in the topic "TI IPC"?

0 Suman Anna over 2 years ago in reply to Jan-Marc Stranz

TI__Guru** 120265 points

Hi Jan,

Jan-Marc Stranz said:
- How does the program to be executed on the DSP core actually get there?

The remoteproc uses the ELF loader and loads a DSP firmware into DDR with the appropriate MMU configurations setup, before releasing the reset of the DSP core.

Jan-Marc Stranz said:
How do I determine the start address and size for the program to run?

The start address comes from the ELF firmware file's entry-point field. This value is used to program the corresponding DSP Boot Vector address. The firmware has to be built to link the appropriate address as the starting entry-point.

Jan-Marc Stranz said:
How can I communicate and exchange data with the program running on the DSP?

This is all done through the rpmsg stack. The bottom-level transport is the virtio-ring based transport.

regards

Suman

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AM5728: Starting/stopping a C66x DSP program under Linux