I'm trying to boot Linux from U-boot on an embedded ARM board using a filesystem on a remote machine served via NFS. It appears that the ethernet connection is not coming up correctly, which results in a failure to mount the NFS share. However, I know that the ethernet hardware works, because U-boot loads the kernel via TFTP.
How can I debug this? I can try tweaking the kernel, but that means recompiling the kernel for every iteration, which is slow. Is there a way that I can make the kernel run without being able to mount an external filesystem?