View source for VAR-SOM-MX7 FreeRTOS for M4 PingPong demo

{{PageHeader|VAR-SOM-MX7 FreeRTOS for M4: RPMsg PingPong demo}} {{DocImage|category1=VAR-SOM-MX7|category2=}} __toc__

== Prerequisites ==
Before you begin, ensure to read [[VAR-SOM-MX7_FreeRTOS_for_M4| Complete Developers Guide]] and follow sections 2,3 and 4.

== Build the demo ==

 cd ~/var-som-mx7_m4-freertos/freertos-variscite/examples/var-som-mx7_m4
 cd demo_apps/rpmsg/pingpong_freertos
 cd armgcc
 export ARMGCC_DIR=~/var-som-mx7_m4-freertos/gcc-arm-none-eabi-5_4-2016q3
 ./build_all.sh > /dev/null

Copy the demo binary to FAT32 partition of boot SD card

 cp release/rpmsg_pingpong_freertos_example.bin /media/BOOT

Gracefully eject the SD card from host machine, plug it in the EVK.

Connect UART2 using pins J5.5 (RX) and J5.7 (TX) as 115200 8N1 for Cortex-M4 debug UART.

Power on on the board and stop the boot process pressing "Enter" key.

Setup and save uboot environment:

 setenv use_m4 yes
 setenv fdtfile undefined
 setenv m4bootdata 0x007F8000
 setenv m4image rpmsg_pingpong_freertos_example.bin
 saveenv

==Start Cortex-M4 demo==

 run m4boot

After the boot process succeeds, the Cortex-M4 terminal displays the following information:

 RPMSG PingPong FreeRTOS RTOS API Demo...
 RPMSG Init as Remote

Start Cortex-A7 core

 run bootcmd

Then login from Yocto console and load the pingpong module:

 modprobe imx_rpmsg_pingpong

After the Linux ping-pong master side module is installed, the Cortex-M4 terminal displays something like:

 Name service handshake is done, M4 has setup a rpmsg channel [1 ---> 1024]
 Get Data From Master Side: 0
 Get Data From Master Side: 11
 Get Data From Master Side: 22
 Get Data From Master Side: 33
 Get Data From Master Side: 44
 ......

A video of the demo starting on our target is available here:

<youtube>9W3BGN568HY</youtube>