again, if what Ruscoff has suggested isn't the case try echo instead of vi:
echo "src/gz all http://repo.opkg.net/edison/repo/all" > /etc/opkg/base-feeds.conf
echo "src/gz edison http://repo.opkg.net/edison/repo/edison" >> /etc/opkg/base-feeds.conf
echo "src/gz core2-32 http://repo.opkg.net/edison/repo/core2-32" >> /etc/opkg/base-feeds.conf