After boot up Minnow Turbot with core-image-sato-sdk image from https://autobuilder.yocto.io/pub/releases/yocto-2.5_M1.rc1 The ethernet is not functioning as igb ethernet controller not enabled.
This will be fixed by the following which unfortunately did not make it into the RC1 build: https://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=e506a6a1314cbfa145d90918cfc131e9d8ad6c82
I have verified it on MinnowBoard Turbot for RC3 release.