MCUBOOT not entering recovery mode

[Bedmonds91]

I am unable to enter recovery mode using the boot button method while testing the bootloader/mcuboot/samples/zephyr/hello-world example on my nRF5340DK board.

Here's the setup:

• Using a brand new nRF5340DK development board.
• Employing a clean example with no modifications to prj.conf and no overlays included.
• Running on an M1 Mac.
• Using nRF Connect for Desktop v4.4.0 with Toolchain Manager v1.3.0.
• Employing nRF Connect SDK v2.5.2 and toolchain v2.5.2.
• Building with the nrf5340dk_nrf5340_cpuapp_ns board selected.

Observing UART output via the nRF Connect Serial Terminal, I receive the following output on reset regardless of whether I hold the boot button:

*** Booting nRF Connect SDK v2.5.2 ***
I: Starting bootloader
I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: none
I: Image index: 0, Swap type: none
I: Bootloader chainload address offset: 0xc000
*** Booting nRF Connect SDK v2.5.2 ***
Hello World from Zephyr on nrf5340dk_nrf5340_cpuapp!

The boot led doesn't react at all either.

Additionally, I've tested the button example to confirm that button0 and led0 operate as expected.

Any insights or suggestions on resolving this issue would be greatly appreciated.

[Sigurd]

Hi!

I hold the boot button:

What button did you press?

From what I can see, you need to hold and press button 1.

https://github.com/nrfconnect/sdk-zephyr/blob/v3.4.99-ncs1/boards/arm/nrf5340dk_nrf5340/nrf5340_cpuapp_common.dtsi#L133

[Bedmonds91]

I pressed the button labelled Button1 which is button0 in the code. I tried all of the available buttons anyway. Just to be clear, I pressed the reset button while holding button1. 

[Sigurd]

Try setting

CONFIG_MCUBOOT_SERIAL=y

ref

https://github.com/hellesvik-nordic/samples_for_nrf_connect_sdk/blob/main/bootloader_samples/serial_recovery/mcuboot_serial_recovery_uart/child_image/mcuboot.conf

[Bedmonds91]

Just tried it, and it is an unknown symbol
Here is the new contents of prj.conf in the hello_world example:

# Print a banner on the UART on startup.

CONFIG_BOOT_BANNER=y

# Enable console and printk()

CONFIG_PRINTK=y

CONFIG_STDOUT_CONSOLE=y

# Enable Zephyr application to be booted by MCUboot

CONFIG_BOOTLOADER_MCUBOOT=y

CONFIG_MCUBOOT_SERIAL=y // Unknown symbol CONFIG_MCUBOOT_SERIAL

I am building with the nrf5340dk_nrf5340_cpuapp board.

[Sigurd]

Hi!

The CONFIG_MCUBOOT_SERIAL should not be in the application prj.conf, but rather in /child_image/mcuboot.conf , so that it get's applied to the mcuboot build.