Override SDK functions which are not declared as __WEAK__

[Sharon Vardi]

Hi all,

In my project i'm using the nrf52840 SoC in my board. 
I'm currently working on the bootloader, and I would like to add additional logic to functions mentiond in the SDK (version 17.1.0) but not defined as __WEAK__,
i.e I can't create my own function using the same name and be sure my function will be called at runtime.

How can I override a function such as so?

For example - 
I want to modify the "nrf_dfu_transports_init" function declared & defined in "nrf_dfu_transport.c" file.
this is the function definition:


Do I have to copy the entire file, change its name and order the compiler to take my file instead of the SDK one (in the .emProject file)? Or is it a better way of doing that without copying the entire file for just one function I want to modify?

[Hieu]

Hell Sharon,

Yes, you essentially need to remove the original implementation from compilation and add in that of yours.

There are several approaches. Replacing the file with your own copy is one way.

Another one is to comment out just the function you want to replace and add the replacement function in one of your source files.

Finally, you could just edit the original source file.

All approaches work, and whether one fits or not depends on the specifics of your project like version controls or code organizations.

Hieu

[Sharon Vardi]

Hi, what do you mean by "comment out" just the function you want to replace?

Eventually the compiler builds the image according to sdk_config and .emProjec files.
if I will tell guide him to include the nrf_Dfu_transport.c file in the compilation process it will also copile the "nrf_dfu_transport_init()" function.

My goal is to remove copied files we have in the project which are 90%+ copy-pasted from the SDK.
My wish is to use only the SDK functions s much as possible

[Hieu]

By comment out, I mean using the comment syntax to remove the code section but still leaving trace of it.

void func_to_be_built(void)
{

}

// void func_not_to_be_built(void)
// {
// 
// }

It is an idea independent of changing which file is built in .emProject.

I think it is reasonable to try to use SDK functions as much as possible; but it is also fine to sometimes modify them if necessary. What kind of issue are you trying to resolve here that necessitates modifying the function?