Effects of Boot Loaders on Applications

[takashina hiroki]

SDK: 15.3.0
SoftDevice: S132
Device: EYSHJNZWZ (nRF52832)

I am considering adding the following bootloader to my project.
nRF5_SDK_15.3.0_59ac345\examples\dfu\secure_bootloader\pca10040_ble

When I added the bootloader, the application stopped working.
When only the application was written, it worked fine.
The cause was that "NRF_BL_DFU_ENTER_METHOD_BUTTON 1" was set.
This caused the event function set in "nrf_drv_gpiote_in_init" not to run.
Setting "NRF_BL_DFU_ENTER_METHOD_BUTTON 0" worked fine.

I thought the boot loader and application were independent of each other.
Therefore, I did not think that the boot loader setting would affect the application.

(1) Is there any way to add a boot loader without affecting the application?
　(e.g. initialize at the beginning of the application)
(2) Are there any settings or processes other than "NRF_BL_DFU_ENTER_METHOD_BUTTON" that affect the application?

[Vidar Berg]

Hi,

I thought the boot loader and application were independent of each other.

You are correct in that they will run as independent programs, but the bootloader is responsible for booting the application on startup, and that will not happen if the bootloader is asked to enter DFU mode instead. You can read more about the boot sequence in the "Secure boot and firmware updates" section of the bootloader documentation.

Best regards,

Vidar

[takashina hiroki]

Thanks for answering.

I am using "nRF5 SDK v15.3.0".
The "Secure boot and firmware updates" you mentioned does not appear to be included in "nRF5 SDK v15.3.0".
Is it correct to assume that the same is true for "nRF5 SDK v15.3.0"?

[Vidar Berg]

Yes, both versions follow the same boot sequence.

[takashina hiroki]

I looked at "Secure boot and firmware updates".
I understood the boot loader boot sequence.

However, my original question was not resolved.
I don't think the answers to my questions are listed there.
Could you please tell me about (1) and (2)?

[Vidar Berg]

Could you maybe try to rephrase your questions now after you have understood the boot sequence? As mentioned in my initial reply, the bootloader and application are 2 separate programs which run independently of each other. This means that NRF_BL_DFU_ENTER_METHOD_BUTTON and other bootloader related settings do not directly affect the application.

[takashina hiroki]

When I added the bootloader, the application stopped working.
When only the application was written, it worked fine.
The cause was that "NRF_BL_DFU_ENTER_METHOD_BUTTON 1" was set.
This caused the event function set in "nrf_drv_gpiote_in_init" not to run.
Setting "NRF_BL_DFU_ENTER_METHOD_BUTTON 0" worked fine.

As mentioned above, the behavior is such that it is affecting the application.
If they are independent of each other, why this behavior?