DHCOM STM32MP1 Linux

Linux virtual machine for development

• Please have a look at: Virtual Machine for Application Development

Linux Kernel

How to build a Kernel

Get sources from Github 1. Start the Console on Linux 2. git clone https://github.com/dh-electronics/linux-stm32mp1.git --branch dev/5.4.69_dhsom 3. cd linux-stm32mp1 Configure and build the Device Tree + Kernel 4. ARCH=arm CROSS_COMPILE=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf- make stm32mp1_dhsom_defconfig 5. ARCH=arm CROSS_COMPILE=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf- make menuconfig (optional: If you want to add/remove Kernel features) 6. ARCH=arm CROSS_COMPILE=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf- make dtbs 7. ARCH=arm CROSS_COMPILE=/opt/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf- make zImage Create the FIT-image with our script (Download link) Interactive mode for selecting device trees Device trees are set as parameter 8. create_fitimage Enter the numbers (space seperated) of the device trees to include (e.g. if you want to include the device tree for the PDK2 include the number of ./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2.dtb (usually 3). Enter the numbers (space seperated) of the device trees overlays to include (e.g. for the PDK2 enter the files which contain PDK2 (usually 8 9 10 11 12 13 14). (Example is for the PDK2) 8. create_fitimage --dtb ./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2.dtb --dtbo ./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-460-200-x11.dtbo,./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-497-200-x12.dtbo,./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-505-200-x12-ch101olhlwh.dtbo,./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-531-100-x21.dtbo,./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-531-100-x22.dtbo,./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-560-200-x12.dtbo,./arch/arm/boot/dts/stm32mp157c-dhcom-pdk2-overlay-638-100-x12-rpi7inch.dtbo

Kernel Userspace Interfaces to Access Hardware

RS-485 on picoITX

RS-485 device

DHCOM UART 2

/dev/ttySTM2

Compilation on target

gcc tty_rs485_test.c -o tty_rs485_test

Set tty device to raw mode

stty -F /dev/ttySTM2 115200 cs8 raw -echo

Send data with demo program

./tty_rs485_test /dev/ttySTM2

Receive data with demo program

./tty_rs485_test /dev/ttySTM2

Download example source code

• tty_rs485_test.c

CAN interface

Setup CAN interface with baudrate 500kbit/sec.

ip link set can0 up type can bitrate 500000

Start to listen on CAN port

candump can0

Send test message

cansend can0 100#11.2233.44556677.88

Deinitialize CAN port

ip link set can0 down