IPCF Shared Memory Sample Application with XEN hypervisor

Copyright:	2023-2024 NXP

Overview

This sample application is a kernel module that demonstrates a polling message communication between Dom0 and Dom0less, using the shared memory driver.

The application initializes the shared memory driver and sends messages to the remote application. When a reply is received from remote application, it wakes up to process the messages and replies after received all expected messages.

This application is controlled from console via a sysfs file (see Running the Application).

Prerequisites

• EVB board for supported processors
• NXP Automotive Linux BSP

Building the application

This module is built with Yocto from NXP Auto Linux BSP, but can also be built manually, if needed.

Note: modules are also included in NXP Auto Linux BSP pre-built images that can

be downloaded from NXP Auto Linux BSP Flexera catalog.

Building with Yocto

1. Follow the steps in Linux BSP User Manual from Flexera catalog for building NXP Auto Linux BSP with Yocto and enable Xen Hypervisor with custom XEN setup is xen-examples-dom0less-passthrough-gmac:

2. Open conf/local.conf file and add:

   BRANCH:pn-ipc-shm="release/**IPCF_RELEASE_NAME**"
   SRCREV:pn-ipc-shm="${AUTOREV}"
   DEMO_IPCF_APPS:pn-ipc-shm="sample_xen/dom0 sample_xen/dom0less"
   EXTRA_OEMAKE:append:pn-ipc-shm=" IPC_USE_XEN=YES "
   

where IPCF_RELEASE_NAME is the name of Inter-Platform Communication Framework release from Flexera catalog and replace the line with SRCREV with SRCREV = "${AUTOREV}".

Modify sources/meta-alb/recipes-extended/xen/xen/xen_s32cc.cfg and add::

CONFIG_STATIC_SHM=y

Modify sources/meta-alb/recipes-fsl/images/fsl-image-dom0less.bb and add::

IMAGE_INSTALL += " devmem2 dtc bridge-utils ipc-shm"

3. Build fsl-image-auto:

   bitbake fsl-image-auto 2>&1
   

Building manually

1. Get NXP Auto Linux kernel and IPCF driver from GitHub:

   git clone https://github.com/nxp-auto-linux/linux
   git clone https://github.com/nxp-auto-linux/ipc-shm
   git -C ipc-shm checkout --track origin/release/**IPCF_RELEASE_NAME**
   

Note: use the release branch: release/IPCF_RELEASE_NAME

where IPCF_RELEASE_NAME is the name of Inter-Platform Communication Framework release from Flexera catalog

2. Export CROSS_COMPILE and ARCH variables and build Linux kernel providing the desired config:

   export CROSS_COMPILE=/<toolchain-path>/aarch64-linux-gnu-
   export ARCH=arm64
   make -C ./linux s32gen1_defconfig
   make -C ./linux
   

3. Build IPCF driver and sample modules providing kernel source location, e.g.:

   make -C ./ipc-shm/sample_xen/dom0 PLATFORM_FLAVOR=[PLATFORM] KERNELDIR=$PWD/linux modules
   make -C ./ipc-shm/sample_xen/dom0less PLATFORM_FLAVOR=[PLATFORM] KERNELDIR=$PWD/linux modules
   
   User must specific the platform::
   
       PLATFORM_FLAVOR=s32g2
       PLATFORM_FLAVOR=s32r45
       PLATFORM_FLAVOR=s32g3
   

Running the application

1. If sample was built manually, copy ipc-shm-xen.ko and ipc-shm-sample-dom0.ko and ipc-shm-sample-dom0less.ko in rootfs
2. Boot Linux: see section "How to boot" from Auto Linux BSP user manual.
3. Stop in uboot:

1. Load the boot script:

ext4load mmc ${mmcdev}:${mmcpart_ext} ${script_addr} boot/${script}; source ${script_addr}

2. Set a shared memory node in device tree:

fdt resize 1024; fdt mknode /chosen shmem@84500000; fdt set /chosen/shmem@84500000 compatible "xen,domain-shared-memory-v1"; fdt set /chosen/shmem@84500000 role "owner"; fdt set /chosen/shmem@84500000 xen,shm-id "shmem0"; fdt set /chosen/shmem@84500000 xen,shared-mem <0x0 0x84500000 0x0 0x84500000 0x0 0x20000>; fdt mknode /chosen/domU0 shmem@84500000; fdt set /chosen/domU0/shmem@84500000 compatible "xen,domain-shared-memory-v1"; fdt set /chosen/domU0/shmem@84500000 role "borrower"; fdt set /chosen/domU0/shmem@84500000 xen,shm-id "shmem0"; fdt set /chosen/domU0/shmem@84500000 xen,shared-mem <0x0 0x84500000 0x0 0x84500000 0x0 0x20000>;

3. Boot:

booti ${xen_addr} - ${fdt_addr}

3. Login with root and insert IPCF kernel modules:

In Dom0::

insmod /lib/modules/uname -r/extra/ipc-shm-xen.ko insmod /lib/modules/uname -r/extra/ipc-shm-sample-dom0.ko

In Dom0less::

insmod /lib/modules/uname -r/extra/ipc-shm-xen.ko insmod /lib/modules/uname -r/extra/ipc-shm-sample-dom0less.ko

4. Clear the kernel log:

   dmesg -c > /dev/null
   

5. Send 10 ping messages to remote domain and display output from kernel log:

To send message from Dom0less to Dom0::

In Dom0less::

cat /sys/kernel/ipc-shm-sample/ping

Then switch to Dom0::

echo 10 > /sys/kernel/ipc-shm-sample/ping

6. Repeat previous step with different number of messages
7. Unload the modules:

In Dom0::

rmmod ipc-shm-sample-dom0 ipc-shm-xen

In Dom0less::

rmmod ipc-shm-sample-dom0less ipc-shm-xen

8. Result:

In Dom0less kernel log, there could be message like below:

(XEN) [  319.082159] ipc-shm-sample: run_demo_poll(): starting demo...
(XEN) [  319.082193] ipc-shm-sample: send_ctrl_msg(): ch 0 >> 20 bytes: SENDING MESSAGES: 10
(XEN) [  319.082210] ipc-shm-sample: send_data_poll(): ch 1 >> 32 bytes: #0 HELLO WORLD! from DOM0
(XEN) [  319.082235] ipc-shm-sample: send_data_poll(): ch 2 >> 32 bytes: #1 HELLO WORLD! from DOM0
(XEN) [  319.082257] ipc-shm-sample: send_data_poll(): ch 1 >> 32 bytes: #2 HELLO WORLD! from DOM0
(XEN) [  319.082280] ipc-shm-sample: send_data_poll(): ch 2 >> 32 bytes: #3 HELLO WORLD! from DOM0
(XEN) [  319.082301] ipc-shm-sample: send_data_poll(): ch 1 >> 32 bytes: #4 HELLO WORLD! from DOM0
(XEN) [  319.082323] ipc-shm-sample: send_data_poll(): ch 2 >> 32 bytes: #5 HELLO WORLD! from DOM0
(XEN) [  319.082344] ipc-shm-sample: send_data_poll(): ch 1 >> 32 bytes: #6 HELLO WORLD! from DOM0
(XEN) [  319.082366] ipc-shm-sample: send_data_poll(): ch 2 >> 32 bytes: #7 HELLO WORLD! from DOM0
(XEN) [  319.082387] ipc-shm-sample: send_data_poll(): ch 1 >> 32 bytes: #8 HELLO WORLD! from DOM0
(XEN) [  319.082410] ipc-shm-sample: send_data_poll(): ch 2 >> 32 bytes: #9 HELLO WORLD! from DOM0
(XEN) [  319.094574] ipc-shm-sample: ctrl_chan_rx_cb(): ch 0 << 19 bytes: SENDING MESSAGES: 0
(XEN) [  319.094604] ipc-shm-sample: data_chan_rx_cb(): ch 1 << 32 bytes: #0 HELLO WORLD! from DOM1
(XEN) [  319.094626] ipc-shm-sample: data_chan_rx_cb(): ch 1 << 32 bytes: #2 HELLO WORLD! from DOM1
(XEN) [  319.094645] ipc-shm-sample: data_chan_rx_cb(): ch 1 << 32 bytes: #4 HELLO WORLD! from DOM1
(XEN) [  319.094664] ipc-shm-sample: data_chan_rx_cb(): ch 1 << 32 bytes: #6 HELLO WORLD! from DOM1
(XEN) [  319.094683] ipc-shm-sample: data_chan_rx_cb(): ch 1 << 32 bytes: #8 HELLO WORLD! from DOM1
(XEN) [  319.094702] ipc-shm-sample: data_chan_rx_cb(): ch 2 << 32 bytes: #1 HELLO WORLD! from DOM1
(XEN) [  319.094721] ipc-shm-sample: data_chan_rx_cb(): ch 2 << 32 bytes: #3 HELLO WORLD! from DOM1
(XEN) [  319.094740] ipc-shm-sample: data_chan_rx_cb(): ch 2 << 32 bytes: #5 HELLO WORLD! from DOM1
(XEN) [  319.094758] ipc-shm-sample: data_chan_rx_cb(): ch 2 << 32 bytes: #7 HELLO WORLD! from DOM1
(XEN) [  319.094777] ipc-shm-sample: data_chan_rx_cb(): ch 2 << 32 bytes: #9 HELLO WORLD! from DOM1
(XEN) [  319.094797] ipc-shm-sample: run_demo_poll(): exit demo