kernel cli: rw by default

rootfs-post-build-script

@@ -3,10 +3,14 @@
 #      make target-finalize
 # which gets called by the default target.
 target_dir="$1"
+# /dev/* entries were taken out of BusyBox inittab,
+# no need to do that on every boot, right?
 mkdir -p \
   "${target_dir}/mnt/9p/data" \
   "${target_dir}/mnt/9p/out" \
   "${target_dir}/mnt/9p/rootfs_overlay" \
+  "${target_dir}/dev/pts" \
+  "${target_dir}/dev/shm" \
 ;
 # Maybe there is a cleaner way to get rid of those files,
 # like disabling some Buildroot packages, but no patience.