Modifying the device tree for a custom board

[garrettb]

Hi

I was developing an application on an nRF52840 DK, using nRF Connect SDK v2.4.1.
I now want to modify this project to run on a custom nRF52840 board.

To learn how to do this, I started with a new Nordic sample: peripheral uart, and I built this (successfully) for the nRF52840 DK.

Now, to create a build for a custom nRF52840 board, instead of the nRF52840 DK, I performed the following steps (adapting the steps described here).

Step 1

I created an 'arm' folder the local board directory under the working project

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peripheral_uart\boards\arm

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peripheral_uart\boards\arm

Step 2

I copied the nRF52840 DK board folder from:

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ncs\v2.4.1\zephyr\boards\arm\nrf52840dk_nrf52840

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ncs\v2.4.1\zephyr\boards\arm\nrf52840dk_nrf52840

to:

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peripheral_uart\boards\arm\

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peripheral_uart\boards\arm\

and renamed the folder:

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peripheral_uart\boards\arm\ customer1_nrf52840

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peripheral_uart\boards\arm\ customer1_nrf52840

Step 3

I renamed filenames in this new folder, from:

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nrf52840dk_nrf52840.dts

nrf52840dk_nrf52840.yaml

nrf52840dk_nrf52840_defconfig

nrf52840dk_nrf52840-pinctrl.dtsi

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nrf52840dk_nrf52840.dts
nrf52840dk_nrf52840.yaml
nrf52840dk_nrf52840_defconfig
nrf52840dk_nrf52840-pinctrl.dtsi

to:

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customer1_nrf52840.dts

customer1_nrf52840.yaml

customer1_nrf52840_defconfig

customer1_nrf52840-pinctrl.dtsi

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customer1_nrf52840.dts
customer1_nrf52840.yaml
customer1_nrf52840_defconfig
customer1_nrf52840-pinctrl.dtsi

Step 4

I renamed all the BOARD_NRF52840DK_NRF52840 to BOARD_CUSTOMER1_NRF52840
in files:

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Kconfig

Kconfig.defconfig

Kconfig.board

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Kconfig
Kconfig.defconfig
Kconfig.board

And in Kconfig.defconfig, renamed Boolean:

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default "nrf52840dk_nrf52840"

default "customer1_nrf52840"

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default "nrf52840dk_nrf52840"
default "customer1_nrf52840"

And in Kconfig.board, renamed Boolean:

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bool "nRF52840 DK NRF52840"

bool "customer1 NRF52840"

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bool "nRF52840 DK NRF52840"
bool "customer1 NRF52840"

Step 5

In customer1_nrf52840.dts, I modified the dtsi include from:

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#include "nrf52840dk_nrf52840-pinctrl.dtsi"

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#include "nrf52840dk_nrf52840-pinctrl.dtsi"

To:

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#include "customer1_nrf52840-pinctrl.dtsi"

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#include "customer1_nrf52840-pinctrl.dtsi"

And the model/compatible, from:

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model = "Nordic nRF52840 DK NRF52840";

compatible = "nordic,nrf52840-dk-nrf52840";

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model = "Nordic nRF52840 DK NRF52840";
compatible = "nordic,nrf52840-dk-nrf52840";

To:

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model = "Nordic customer1 NRF52840";

compatible = "nordic,customer1-nrf52840";

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model = "Nordic customer1 NRF52840";
compatible = "nordic,customer1-nrf52840";

Step 6

In customer1_nrf52840_defconfig, I modified the board config include from:

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CONFIG_BOARD_NRF52840DK_NRF52840=y

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CONFIG_BOARD_NRF52840DK_NRF52840=y

To:

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CONFIG_BOARD_CUSTOMER1_NRF52840=y

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CONFIG_BOARD_CUSTOMER1_NRF52840=y

Step 7

In customer1_nrf52840.yaml, modified the identifier and name, from:

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identifier: nrf52840dk_nrf52840

name: nRF52840-DK-NRF52840

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identifier: nrf52840dk_nrf52840
name: nRF52840-DK-NRF52840

to:

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identifier: customer1_nrf52840

name: customer1-DK-NRF52840

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identifier: customer1_nrf52840
name: customer1-DK-NRF52840

Step 8

I added the following line in CMakeLists.txt, to add the local board information:

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list(APPEND BOARD_ROOT ${CMAKE_CURRENT_SOURCE_DIR})

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list(APPEND BOARD_ROOT ${CMAKE_CURRENT_SOURCE_DIR})

Step 9

I closed VSCode and re-opened it, then defined a new custom build configuration:

Result:

The application builds, using the customer dts and dtsi files.

Question:

Is this the correct way to modify an application to use a custom device?
Did I miss anything?

Regards

Garrett