After standalone usleep recipe was added in wr-base layer, there are multiple usleep binaries existing in different folders as follows: /bin/usleep, /usr/bin/usleep.
1 configure a standard project. 2 make -C build busybox.addpkg 3 make -C usleep.addpkg 4 make fs then check out the rootfs: /bin/usleep is provided by busybox package /usr/bin/usleep is provided by usleep package
