[FAQ] Does the DM R5F need to run the IPC Echo demo task?

No. The DM R5F can run other projects as well.

Processors with a DM R5F need the device manager (DM) task to be running on the DM R5F. So you DO need a firmware loaded and running on the DM R5F. And that firmware needs to start the DM task by calling sciServer_init(). But that firmware does not need to be the MCU+ SDK ipc_rpmsg_echo_linux project.

For more information about DM R5F development, refer to the processor academy > Multicore > Application Development on Remote Cores > Developing on the DM R5F
AM62x || AM62Ax || AM62Px

What is the IPC_Echo demo used for?

The TI Linux developers use the IPC Echo demo for software validation (i.e., is the non-Linux core running, and are the Linux drivers able to successfully interact with the non-Linux core).

A customer could also use the IPC Echo task as a starting point for developing custom DM R5F code that ran alongside the DM task. The customer would then replace the ipc_rpmsg_echo_linux firmware with their custom firmware.

Since this demo code is only really used during development, the IPC Echo task does not actually do anything during a normal customer usecase.

Wait a minute. The DM task is communicating with all the processor cores, right? How does the DM task do inter-processor communication (IPC)?

The DM task hosts a SciServer. All resource management & power management requests between the rest of the processor and the DM task are TI-SCI messages, not RPMessage messages. So normal device operation is not dependent upon RPMsg between the DM R5F & Linux.

Why is the ipc_rpmsg_echo_linux project used for the prebuilt binary?

We evaluated replacing the prebuilt ipc_rpmsg_echo_linux binary with a prebuilt "empty" binary (i.e., only DM task, no other tasks running). However, at this point in time, there is a lot of Linux infrastructure in a lot of different places that relies on a prebuilt binary named "ipc_echo_testb_mcu1_0_release_strip.xer5f". We decided that it would be too much work, and too much confusion for customers, to replace the default firmware.

Customers or FAEs who are comfortable with MCU+ development could replace the prebuilt ipc_echo_testb_mcu1_0_release_strip.xer5f binary with a different binary, like the empty project. For more information, refer to  [FAQ] How to ensure that the DM task is the only code running on the DM R5F? 

I do not want to build my own MCU+ firmware. Are there any other prebuilt DM R5F binaries that I can use?

AM62x, AM62Px, AM67, AM67A

At this point in time, ipc_rpmsg_echo_linux is the only project with an "official" prebuilt binary.

This FAQ provides guidance on how to modify the empty project to run on the same processor as a Linux A53 core. It also includes several prebuilt binary files:
[FAQ] How to ensure that the DM task is the only code running on the DM R5F? 

AM62Ax

The VPAC/ISP firmware is the other "official" prebuilt binary. It is located in the AM62Ax Linux SDK at board-support/prebuilt-images/ti-dm/am62axx/ipc_echo_testb_mcu1_0_release_strip.xer5f. This firmware is generated from AM62Ax Firmware Builder instead of the MCU+ SDK.