IPC RP Message Linux Echo

Table of Contents

• Introduction
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Introduction

This example shows usage of RP Message APIs to exchange messages between RTOS/NORTOS CPUs as well as exchange message with Linux on Cortex-A CPU.

In this example,

• We create two RP Message end points
  • One end point to exchange messages with Linux kernel
  • One end point to exchange messages with Linux user space and other RTOS/NORTOS CPUs
• All cores on startup after driver initialization first wait for Linux to be ready
• Then they announce the end points on which they are waiting for messages to Linux.
• This is needed to be done else Linux cannot initiate message exchange with RTOS/NORTOS CPUs.
• Two tasks are then created which listen for incoming messages and echo it back to the sender. The sender can be Linux CPU or other RTOS/NORTOS CPUs.
• Meanwhile Linux kernel and user space test applications initiate message exchange with RTOS/NORTOS CPUs and wait for the echoed message.
• The example also shows a "main" RTOS/NORTOS CPU exchanging message with other RTOS/NORTOS CPUs by sending messages to the same end point as that where LInux sends messages.
• This shows that all CPUs can exchange messages with each other, no matter which OS or RTOS or NORTOS is running on the sender or receiver CPUs.

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0 freertos
	r5fss0-1 freertos
	r5fss1-0 freertos
	r5fss1-1 freertos
	m4fss0-0 freertos
Toolchain	ti-arm-clang
Board	am64x-evm
Example folder	examples/drivers/ipc/ipc_rpmsg_echo_linux

Steps to Run the Example

Note

This is a system or multi-core project, so refer to system project build instructions for CCS project or makefiles when building the example.

• When using CCS projects to build, import the system CCS project and build it using the CCS project menu (see Using SDK with CCS Projects). This will build all the dependant CPU projects as well
• When using makefiles to build, build the system makefile using make command (see Using SDK with Makefiles). This will build all the dependant CPU makefiles as well.
• To run this demo, Linux needs to run on the Cortex A-core. Refer to Processor SDK Linux user guide to load and run this example.

See Also

IPC RPMessage

Sample Output

There is no direct output from the RTOS/NORTOS CPUs on the UART or CCS console. The output is seen on the Linux console on Cortex-A CPU.