I have "huawei echolife hg8145v5" and searched almost all the custom router firmware like DD_WRT , Open WRT but I found nothing related

This router comes with Airtel broadband and it is locked with Airtel only i can't use this router with other broadband provider and stock firmware have no wireless repeater settings which is needed

Is there any way to build open source router firmware form source code for this particular router or I can install linux in router so I can have all networking tool available for it by maintaining limited Ram and processor of router