Custom board DFU on USB port on VS Code

[frax84]

Hello,

i'm using VS Code + Nrf Connect SDK (SDK/Toolchain 2.3.0) to develop firmware for a custom board based on nrf5340. I'm trying to use the USB port of the board (connected to D+ and D- pins of the nrf5340 chip) for both debugging (serial console) and firmware upgrade (DFU). My dream-goal would be having the custom board to behave similarly to a nrf5340DK: i can connect it through USB, it pops up automatically on "Connected Devices" VS Code view and i can flash it pressing "Flash" on Action View. Generally, it would be enough to be able to program it using the USB with whatever software.

Until now, starting from this tutorial and consulting a lot of Kconfig reference and the Zephyr board porting guide i have been able to achieve the following results:

- Build (using VS Code) and flash (using SWD port) the hello world example specifically for my custom board (with custom_board.dts, custom_board_defconfig, etc.)

- Enable MCUBoot subsystem

- Build correctly using MCUMGR options (see prj.conf code below);

- Enable USB console (my "Helloworld" printk statements are printed on serial console through USB connection, tested using Putty software)

However, i'm still missing something to enable DFU. I know that i need to start from SMP_server_sample and configurate MCUMGR correctly, but i'm a bit confused on what is the working procedure.

Here below is my proj.conf

# --------------------------------------- MCUBOOT CONFIG SETTINGS --------------------------------------#

# Enable mcumgr.
CONFIG_MCUMGR=y

# Enable most core commands.
CONFIG_MCUMGR_CMD_IMG_MGMT=y
CONFIG_MCUMGR_CMD_OS_MGMT=y

# Ensure an MCUboot-compatible binary is generated.
CONFIG_BOOTLOADER_MCUBOOT=y

# Enable the serial mcumgr transport.
CONFIG_MCUMGR_SMP_UART=y

# --------------------------------------- RTT CONSOLE CONFIG SETTINGS --------------------------------------#
#Use this config as alternatives to USB console. USB needs "UART_CONSOLE" dependency, here disabled, so they cannot be used together

# Disable UART Console and enable the RTT console
#CONFIG_UART_CONSOLE=n
#CONFIG_RTT_CONSOLE=y
#CONFIG_USE_SEGGER_RTT=y

# Some command handlers require a large stack.
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096


# --------------------------------------- USB CONFIG SETTINGS --------------------------------------#

# Enable the USB stack
CONFIG_USB_DEVICE_STACK=y

# Enable the CDC_ACM service -> the connected device will emulate a modem or serial port
CONFIG_USB_CDC_ACM=y

# Configure name, Product Id and Vendor ID of the USB device
CONFIG_USB_DEVICE_PRODUCT="My Custom board"
CONFIG_USB_DEVICE_PID=0x0110
# CONFIG_USB_DEVICE_VID=0x2FE3   // Zephyr project Device ID - Only for development

# Inizialize USB automatically at boot time
CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=y

# Enable console inputs and UART based drivers -> Logger and shell can be used on USB
CONFIG_UART_INTERRUPT_DRIVEN=y 

and here below i put the interested parts of my dts:

/ {
	model = "my_custom_board";
	compatible = "cnr-imm,my_custom_board";

	chosen {
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
		zephyr,console = &cdc_acm_uart0;
		zephyr,shell-uart = &uart0;
		zephyr,uart-mcumgr = &uart0;
				
		/* shared memory reserved for the inter-processor communication */
		zephyr,ipc_shm = &sram0_shared;
	};
};


	        

I'm missing something probably both in prj.conf (maybe CONFIG_UART_CONSOLE_MCUMGR?) and dts (maybe zephyr,uart-mcumgr = &uart0 is wrong?). Moreover, i'm missing something aboout procedure (is it possible to flash the custom board using VS Code?)

Thank you for any hint you can provide me

Frax

[Einar Thorsrud]

Hi,

The nRF5340 DK has an onboard debugger (on recent versions that is another nRF5340 with Segger firmware). For a custom board you will need that in order to be able to debug it. Without it the only thing you can get via USB is logging via CDC ACM, which I see you already got working.

nRF Connect for VS Code only supports flashing via a debugger, it has no DFU support, so that needs to be handled separately (typically via mcumgr).

To get DFU via USB working for development and also logging via DFU working I would consider using serial recovery with USB, so that the USB is used only for DFU in MCUboot and only for logging/console when the application is running. A colleague of mine have made some samples for serial recovery, including via USB here, which I suggest you refer to. 

[frax84]

This is some nice stuff to study! Thank you! I'll study the examples you linked and i'll let you know as soon as possible (reasonably few days).

[frax84]

Here i come again,

it has been very hard to understand what i needed. There is a lot of confusing materials due to the fragmentation in nrf connect sdk and zephyr versions. There are tons of variations on the theme. In the end, i'm still stuck with my issue, but at least now i have an "improved knowledge" on the topic.

Respect to the last time i created a "child_image" folder and a "mcuboot.conf" file with these settings:

# Enable MCUboot Serial Recovery
CONFIG_MCUBOOT_SERIAL=y
CONFIG_UART_CONSOLE=n

# Point Serial Recovery to CDC_ACM
CONFIG_BOOT_SERIAL_CDC_ACM=y

CONFIG_BOOT_SERIAL_UART=y

# Enable wait for DFU functionality
CONFIG_BOOT_SERIAL_WAIT_FOR_DFU=y
CONFIG_BOOT_SERIAL_WAIT_FOR_DFU_TIMEOUT=5000

After several attempts, i decided to NOT modify my "CMakeLists.txt" file but i verified that the "mcuboot.conf" file is used in my build log. I don't know if i need to add anything in this file, there is a lot of contradictory material here and there.

By now, i'm able to compile my "Hello world" with MCUBOOT enabled and DFU Serial with wait timeout on CDC_ACM for nrf5340dk board but it doesn't build for my custom board. It could be something related to dts file, but i'm trying casually, and a focused hint would be more effective!

EDIT: For some reason i'm not able to add my build log.

[Einar Thorsrud]

Hi,

frax84 said:

After several attempts, i decided to NOT modify my "CMakeLists.txt" file but i verified that the "mcuboot.conf" file is used in my build log. I don't know if i need to add anything in this file, there is a lot of contradictory material here and there.

There are several way to achieve most things, so you do not necessarily need a specific configuration file, as long as you get the configurations you need in somehow (though some methods are cleaner than others, like trying to ensure that project specific changes are in your project files and not in the SDK in general, and that board specific settings are in your board file etc).

frax84 said:

By now, i'm able to compile my "Hello world" with MCUBOOT enabled and DFU Serial with wait timeout on CDC_ACM for nrf5340dk board but it doesn't build for my custom board. It could be something related to dts file, but i'm trying casually, and a focused hint would be more effective!

In order to give specific feedback we need to know more about both your project and how things fail. Can you share your project files and board files and the full build log where it fails?

frax84 said:

EDIT: For some reason i'm not able to add my build log.

Some file suffixes are not possible to upload here. Could you try zipping it (together wit the other files I requested)? Then drag-and drop into the editor window here on DevZone. Alternatively, you also share logs etc via Insert -> Code and copy-past the content there.

[frax84]

Einar Thorsrud said:

There are several way to achieve most things, so you do not necessarily need a specific configuration file, as long as you get the configurations you need in somehow (though some methods are cleaner than others, like trying to ensure that project specific changes are in your project files and not in the SDK in general, and that board specific settings are in your board file etc).

I assume the approach i used (making a child_image folder with conf file inside) goes in the direction of being "cleaner", that is always a good practice. It's just troubling/confusing to have to collect/filter the right material from many sources, but that's how open source some times works!

Einar Thorsrud said:

Some file suffixes are not possible to upload here. Could you try zipping it (together wit the other files I requested)? Then drag-and drop into the editor window here on DevZone. Alternatively, you also share logs etc via Insert -> Code and copy-past the content there.

I tried the "insert->Code" route, but for some reason it sometimes fail (i press OK but nothing happens). It's really random. As you could see i use "insert->Code" very often. I'm attaching a zip file. You will find all the project files and settings (boards included). In the main directory you will find "build log.txt", where i copy-pasted the build log.

6403.hello_world_test.zip

Again, thank you for your support

Frax