Changing MAC address of nRF7002

Question

Hello,

I'm currently working on a custom board using nRF5340 and nR7002 and the nRF7002 MAC address is not yet set in the OTP.
After reading this post, I'm now trying to use the NET_REQUEST_ETHERNET_SET_MAC_ADDRESS to change it manually before using the interface.

My function to change the MAC address is :

int8_t wifi_set_mac_address(){
    struct net_if *iface = net_if_get_default();
    uint8_t mac_addr[6] = {0xF0, 0xCE, 0x36, 0x00, 0x00, 0x4A};

    struct ethernet_req_params eth_param;
    memcpy(eth_param.mac_address.addr, mac_addr, 6);

    if(net_if_down(iface)){
        printk("<Err> Couldn't shutdown WiFi interface\n");
        return -1;
    }
    printk("<Inf> Setting MAC address\n");
    if(net_mgmt(NET_REQUEST_ETHERNET_SET_MAC_ADDRESS,iface, &eth_param, sizeof(struct ethernet_req_params))){
        printk("<Err> Couldn't set new MAC Address\n");
        return -2;
    }

    int ret = memcmp(net_if_get_link_addr(iface)->addr, mac_addr, sizeof(mac_addr));
    if(ret){
        printk("<Err> Couldn't change MAC address\n");
    }

    if(net_if_up(iface)){
        printk("<Err> Couldn't wake up interface\n");
        return -3;
    }
    
    return 0;
}

After a few tries, it appears that the net_if_down() function fails as if the interface wasn't yet up and couldn't be taken down. Unfortunately, if I comment this section it seems that I manage to change the MAC address but I consistently get a Core dump when trying to use the function net_if_up() function.

Do you have any idea on what could cause this core dump ? I though I had followed the example code but I may have made some mistakes.

Thanks,
Regards

Joakim Jakobsen · Accepted Answer

Hi. 
 I haven't tested this myself, but I can test it and see what results I get. 
 Which SDK version are you working with? Just to make sure we have the same setup, other than the fact that you are working with a custom board. 
 From the post you linked to it seems to be working for others. Have you tested using a nRF7002-DK? 
 Br, Joakim

BENBF · Answer

Hello, 
 Thank you for your answer, I'm using SDK version 2.4.2. I finally managed to change the mac address using the net_if_set_link_addr() function. 
 Thank you, Best regards

Changing MAC address of nRF7002

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