M4 Control Tool for i.MX platforms

1. Introduction

This application is an example of controlling M4 core from A core: stop, start, deploy a new firmware for M4 into TCM. Depending on the used platform, the application can be only user space or to have a light component in kernel space and one in user space.

Supported platforms: i.mx8qm and i.mx8qxp

2. Build Instructions

For i.mx8, it is needed to build the kernel module and user space application.

2.1 Setup the environment:

# Path to kernel building directory. It recommended to point directly to the built kernel from Yocto.

export KDIR=/work/platforms/imx/yocto/imx8/bld-x11/tmp/work/imx8qmlpddr4arm2-poky-linux/linux-imx/4.9.11-r0/build

# Architecture

export ARCH=arm64

# Path to the used cross-compiler

export CROSS_COMPILE=/home/disk2b/toolchain/gcc-linaro-aarch64-linux-gnu-4.9-2014.09_linux/aarch64-linux-gnu- export SOC=

# Build the application and kernel module

make

For i.mx6 and i.mx7, it is needed to build only the user space application.

2.1 Setup environment:

# Initialize the environment by sourcing an environment setup script from yocto toolchain generated for desired platform

. /opt/fsl-imx-x11/4.1.33-7ulp_beta/environment-setup-cortexa7hf-neon-poky-linux-gnueabi

# Export SOC variable for the desired platform

export SOC=

# Build the application

make

3. Run instructions

# Instructions for i.mx8 platform

Note: 1. This application assumes that the M4 apps are compiled for TCM in order to be in sync with MCU SDK release (SDK_2.2_VAL-MIMX8QM_M4). If other memories are needed for M4 app, please update these macros from include/m4ctrl.h. Please note that some memories will likely need to be reserved from Linux dtb in order to be excluded from the memory used by linux. 2. hello_world app for M4 was used for testing.

3.1 Insert the kernel module

insmod m4ctrl_dev.ko

3.2 Run the app:

Examples - i.mx8QM

root@imx8qmlpddr4arm2:~# ./m4ctrl --deploy=./m4_image_c0.bin --core=0

root@imx8qmlpddr4arm2:~# ./m4ctrl --stop --core=0

root@imx8qmlpddr4arm2:~# ./m4ctrl --start --core=0

root@imx8qmlpddr4arm2:~# ./m4ctrl --deploy=./m4_image_c1.bin --core=1

root@imx8qmlpddr4arm2:~# ./m4ctrl --stop --core=1

root@imx8qmlpddr4arm2:~# ./m4ctrl --start --core=1

# Instructions for i.mx6 and i.mx7 platforms

Note: 1. This application assumes that the M4 apps are compiled for TCM and the cortex M4 is started from uboot. 2. hello_world app for M4 was used for testing.

3.1 Run the app:

Examples: - i.mx6sx

U-boot shell

=> run m4boot

Linux shell

root@imx6sxsabresd:~# ./m4ctrl --deploy=hello_world.bin

4. Known limitations:

Cortex M4 should be started from u-boot on imx6 and imx7 platforms.
Due to known hardware TLB issue, sometimes the application will block on IMX8QM.