IPC service: RPMSG-Lite backend

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Overview

This application demonstrates how to use the IPC Service with the RPMSG-Lite backend in Zephyr. It is designed to show how to integrate the backend from both a build and code perspective.

The sample is functionally equivalent to the OpenAMP static_vrings IPC service sample but uses RPMSG-Lite as the underlying transport.

Three IPC instances are demonstrated, each running sequentially (instance N starts only after instance N-1 has completed its exchange):

  • Instance 0: standard copy-based send/receive between host and remote using a single named endpoint.

  • Instance 1: zero-copy nocopy API (ipc_service_get_tx_buffer / ipc_service_send_nocopy / ipc_service_release_rx_buffer).

  • Instance 2: second copy-based instance, demonstrating that the platform_notify() owner-search correctly routes notifications to the matching link-id even when multiple non-owner instances share a single physical MBOX channel.

RPMSG-Lite requires an MBOX driver with data-transfer mode. A single pair of MBOX channels (TX + RX) is shared across all IPC instances via the notification-parent DT property; the link-id DT property selects which RPMSG-Lite link a given instance belongs to. Link IDs must be sequential starting from 0.

Building and Running

The sample supports the boards listed in tests.yaml. Build with sysbuild to compile both the host and remote images in one step:

# From the root of the zephyr repository
west build -b mimxrt1170_evk@B/mimxrt1176/cm7 --sysbuild samples/subsys/ipc/ipc_service/rpmsg_lite
west flash

Open a serial terminal (minicom, putty, etc.) and connect the board with the following settings:

  • Speed: 115200

  • Data: 8 bits

  • Parity: None

  • Stop bits: 1

Reset the board and the following messages will appear on the corresponding serial ports (one for host, one for remote):

*** Booting Zephyr OS build v4.x.x ***
IPC-service HOST [INST 0] demo started
HOST [0]: 1
HOST [0]: 3
HOST [0]: 5
HOST [0]: 7
HOST [0]: 9
HOST [0]: 11
HOST [0]: 13
HOST [0]: 15
HOST [0]: 17
HOST [0]: 19
IPC-service HOST [INST 0] demo ended.
IPC-service HOST [INST 1] demo started
HOST [1]: 1
HOST [1]: 3
HOST [1]: 5
...
HOST [1]: 37
HOST [1]: 39
IPC-service HOST [INST 1] demo ended.
IPC-service HOST [INST 2] demo started
HOST [2]: 1
HOST [2]: 3
HOST [2]: 5
HOST [2]: 7
HOST [2]: 9
HOST [2]: 11
HOST [2]: 13
HOST [2]: 15
HOST [2]: 17
HOST [2]: 19
IPC-service HOST [INST 2] demo ended.

*** Booting Zephyr OS build v4.x.x ***
IPC-service REMOTE [INST 0] demo started
REMOTE [0]: 0
REMOTE [0]: 2
REMOTE [0]: 4
REMOTE [0]: 6
REMOTE [0]: 8
REMOTE [0]: 10
REMOTE [0]: 12
REMOTE [0]: 14
REMOTE [0]: 16
REMOTE [0]: 18
IPC-service REMOTE [INST 0] demo ended.
IPC-service REMOTE [INST 1] demo started
REMOTE [1]: 0
REMOTE [1]: 2
REMOTE [1]: 4
...
REMOTE [1]: 36
REMOTE [1]: 38
IPC-service REMOTE [INST 1] demo ended.
IPC-service REMOTE [INST 2] demo started
REMOTE [2]: 0
REMOTE [2]: 2
REMOTE [2]: 4
REMOTE [2]: 6
REMOTE [2]: 8
REMOTE [2]: 10
REMOTE [2]: 12
REMOTE [2]: 14
REMOTE [2]: 16
REMOTE [2]: 18
IPC-service REMOTE [INST 2] demo ended.

See also

IPC