examples/mock_modules_dir/mock_module/mock_module.cc

#include "mock_module.h"
#include <zephyr/init.h>
#include <zephyr/sys/printk.h>

int mock_module_func() {
    return 42;
}

static int mock_module_init(void) {
    printk("MOCK_MODULE_INIT: Mock module initialized!\n");
    return 0;
}

SYS_INIT(mock_module_init, APPLICATION, 90);