Do not download random .bin files from sketchy file hosting sites. Malicious firmware can turn your router into a botnet node.
: A Linux-based kernel tailored for Broadcom's MIPS or ARM-based architectures. bcm63381b0 firmware full
Broadcom chipsets are notoriously difficult for open-source developers because of proprietary binary blobs (drivers) for DSL and Wi-Fi. Do not download random