DHCOM STM32MP1 Linux

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Linux virtual machine for 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

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