Enable mcumgr features on NRF5340 DK board while Bluetooth HCI_USB program is running

[Utsav R Shah]

Hello community,

I am trying for multiple firmware updates for my NRF5340 DK board. 

What I am doing is I have build and flashed the SMP server sample program found /zephyr/samples/subsys/mgmt/mcumgr/smp_svr

After flashing this application, I can see my board recognised as a ttyACM0 device while I perform ls /dev.

Using the mcumgr tool I am also able to flash the Bluetooth HCI_USB sample program and after confirming the image and resetting the board, the board now acts as a bluetooth controller. I can verify this using the bluetoothctl command.

Now If I want to do a firmware upgrade, I dont have any way in the HCI_USB application to go back to smp server application. How can I perform multiple firmware updates using mcumgr?

Can virtual com port concept be useful here? If yes then I would like to have a detailed tutorial for this .

[Hieu]

Hello Utsav,

In a different DevZone case, I was able to emulate two UART COM on the same USB peripheral simply by setting one more cdc_acm_uart node under the usbd node. 

		usbd: zephyr_udc0: usbd@40027000 {
			compatible = "nordic,nrf-usbd";
			reg = < 0x40027000 0x1000 >;
			interrupts = < 0x27 0x1 >;
			num-bidir-endpoints = < 0x1 >;
			num-in-endpoints = < 0x7 >;
			num-out-endpoints = < 0x7 >;
			num-isoin-endpoints = < 0x1 >;
			num-isoout-endpoints = < 0x1 >;
			status = "okay";
			cdc_acm_uart: cdc_acm_uart {
				compatible = "zephyr,cdc-acm-uart";
			};
			cdc_acm_uart0: cdc_acm_uart0 {
				compatible = "zephyr,cdc-acm-uart";
				label = "CDC_ACM_0";
			};

Once that second virtual COM port is setup, you can select it for MCUmgr by overlaying the chosen property as such:

/{
	chosen {
		zephyr,uart-mcumgr = &new_usb_uart_com;
	};
}

Please note that it is the Christmas - New Year holiday season here. We are thus severely understaffed, and there would be delays in responses. Our apologies for the inconveniences. 

Hieu

[Utsav R Shah]

Hello Hieu  thanks for your response. I understand Christmas season is here and most of  the people would be on vacations. I really appreciate your response. 

In the Bluetooth HCI_USB project I have done the following changes : 

I have tried modifying the overlay file and here are the results : 

The contents of my overlay file are as follows: 

/ {
chosen {
zephyr,code-partition = &slot0_partition;
zephyr,out-usb = &cdc_acm1;
zephyr,uart-mcumgr = &cdc_acm0;
};
};

&zephyr_udc0 {
cdc_acm0: cdc_acm0 {
compatible = "zephyr,cdc-acm-uart";
};
cdc_acm1: cdc_acm1 {
compatible = "zephyr,cdc-acm-uart";
};
};

&uart0 {
status = "okay";
};

The contents of my prj.conf file are as follows:

CONFIG_STDOUT_CONSOLE=y
CONFIG_GPIO=y
CONFIG_SERIAL=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=n

CONFIG_BT=y
CONFIG_BT_HCI_RAW=y

CONFIG_USB_DEVICE_STACK=y
CONFIG_USB_DEVICE_PID=0x000B
CONFIG_USB_DEVICE_BLUETOOTH=y
CONFIG_USB_DEVICE_BLUETOOTH_VS_H4=n

# Workaround: Unable to allocate command buffer when using K_NO_WAIT since
# Host number of completed commands does not follow normal flow control.
CONFIG_BT_BUF_CMD_TX_COUNT=10

#This flag is enabled to make the mcuboot features for DFU available
CONFIG_BOOTLOADER_MCUBOOT=y

#Commands to add composite USB feature to HCI_USB program
#Composite USB configuration ----------------
CONFIG_USB_COMPOSITE_DEVICE=y
#CONFIG_USB_CDC_ACM=y

# Enable MCUmgr and dependencies.
CONFIG_NET_BUF=y
CONFIG_ZCBOR=y
CONFIG_CRC=y
CONFIG_MCUMGR=y
CONFIG_STREAM_FLASH=y
CONFIG_FLASH_MAP=y

# Some command handlers require a large stack.
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2304
CONFIG_MAIN_STACK_SIZE=2048

# Enable flash operations.
CONFIG_FLASH=y

# Required by the `taskstat` command.
CONFIG_THREAD_MONITOR=y

# Support for taskstat command
CONFIG_MCUMGR_GRP_OS_TASKSTAT=y

# Enable statistics and statistic names.
CONFIG_STATS=y
CONFIG_STATS_NAMES=y

# Enable most core commands.
CONFIG_FLASH=y
CONFIG_IMG_MANAGER=y
CONFIG_MCUMGR_GRP_IMG=y
CONFIG_MCUMGR_GRP_OS=y
CONFIG_MCUMGR_GRP_STAT=y

# Enable logging
CONFIG_LOG=y
CONFIG_MCUBOOT_UTIL_LOG_LEVEL_WRN=y

# Disable debug logging
CONFIG_LOG_MAX_LEVEL=3

# Enable USB subsystem
CONFIG_USB_DEVICE_STACK=y
CONFIG_SERIAL=y
CONFIG_UART_LINE_CTRL=y
CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=n
CONFIG_CONSOLE=y
# USB backend is serial device
CONFIG_MCUMGR_TRANSPORT_UART=y
CONFIG_BASE64=y

Then I have build the project using the following command : 

west build -b nrf5340dk_nrf5340_cpuapp --pristine -- -DOVERLAY_CONFIG=overlay-cdc.conf -DDTC_OVERLAY_FILE=nrf5340_cpuapp.overlay -DCONFIG_MCUBOOT_SIGNATURE_KEY_FILE=\"/home/mutsl04176/ncs/v2.4.2/bootloader/mcuboot/root-rsa-2048.pem\"

After successful build, I flashed the program into the NRF5340 DK board and plugged in the other USB.

You can see from the screenshot below that I get two virtual ports as ACM0 and ACM1 :

But at the same time, the board is not visible as a Bluetooth controller under bluetoothctl . Only the default Bluetooth controller (of the laptop) is visible.

How do I solve this? 

Any other modifications that needs to be made? If yes then please let me know in which file and what needs to be done. 

Thanks!

[Sigurd Hellesvik]

The error says

"devicetree error: /chosen: undefined node label 'cdc_acm_uart'"

How is the CDC ACM node defined in your DTS?

[Utsav R Shah]

Where do I check that? I mean where would the dts file be present?

[Sigurd Hellesvik]

I think the easiest way to find this is to look at build/zephyr/zephyr.dts for the previous working build

[Utsav R Shah]

I have given the contents of the dts file in the reply above, you can check that

[Sigurd Hellesvik]

I suggest that you loom through that file yourself and look for cdc.
I hope not only to help you with this specific, but also to help you learn how to debug this kind of issue yourself.

[Utsav R Shah]

Sigurd Hellesvik  Thank you so much for taking the time to understand my problem. That is really appreciable.

Looking at the zephyr.dts file present in build/zephyr directory, I could find this code snippet that I have attached. I think this may be how cdc_acm is defined 

usbd: zephyr_udc0: usbd@36000 {
				compatible = "nordic,nrf-usbd";
				reg = < 0x36000 0x1000 >;
				interrupts = < 0x36 0x1 >;
				num-bidir-endpoints = < 0x1 >;
				num-in-endpoints = < 0x7 >;
				num-out-endpoints = < 0x7 >;
				num-isoin-endpoints = < 0x1 >;
				num-isoout-endpoints = < 0x1 >;
				status = "okay";
				cdc_acm0: cdc_acm0 {
					compatible = "zephyr,cdc-acm-uart";
				};
				cdc_acm1: cdc_acm1 {
					compatible = "zephyr,cdc-acm-uart";
				};
			};

[Sigurd Hellesvik]

And then we can have a look at where the sample I mentioned sets up cdc_acm:

zephyr_udc0: &usbd {
	compatible = "nordic,nrf-usbd";
	status = "okay";

	cdc_acm_uart: cdc_acm_uart {
		compatible = "zephyr,cdc-acm-uart";
	};
};

You see how they defined cdc_acm_uart?
cdc_acm_uart is just the name set in the example. Which name did you give the same type of node in your dts?

[Utsav R Shah]

I'm actually confused now on how to do this. Since I am completely new to this, I actually need some direct hand holding for this. Any chance I can connect with someone directly from the community or with you?

[Sigurd Hellesvik]

I will try to continue to explain a bit further. In your code you got:

	cdc_acm0: cdc_acm0 {
		compatible = "zephyr,cdc-acm-uart";
    };

And the example got:

	cdc_acm_uart: cdc_acm_uart {
		compatible = "zephyr,cdc-acm-uart";
	};

Your node is named cdc_acm0, and the sample node is named cdc_acm_uart.
It is the name of the node which you point to in the "chosen" part of the DTS.

The error message is because you use cdc_acm_uart for your chosen node. But cdc_acm_uart does not exist for your code. Instead the CDC node in your code is named cdc_acm0

Does that make sense?

[Utsav R Shah]

Yes I now kind of understand what you are saying and I have modified my overlay file accordingly. Please have a look : 

/ {
	chosen {
	   zephyr,code-partition = &slot0_partition;
	   zephyr,out-usb = &cdc_acm1;
	   zephyr,uart-mcumgr = &cdc_acm0;
	   zephyr,bt-mon-uart = &cdc_acm1;
	   zephyr,bt-c2h-uart = &cdc_acm2;
	   
	};
 };

&zephyr_udc0 {
	cdc_acm0: cdc_acm0 {
		compatible = "zephyr,cdc-acm-uart";
	};
	cdc_acm1: cdc_acm1 {
		compatible = "zephyr,cdc-acm-uart";
	};
	cdc_acm2: cdc_acm2 {
		compatible = "zephyr,cdc-acm-uart";
	};
};

&uart0 {
	status = "okay";
};

Now the code compiles successfully and I was able to flash it. But the problem still remains the same. I am not able to see the device as a bluetooth controller. But when I check the device list, I can see the 3 ACM ports that are created. Only the default bluetooth controller of my laptop is visible.