Move debugfs, rootfs and procfs documentation to README

rootfs_overlay/debugfs.sh

@@ -1,22 +1,13 @@
 #!/bin/sh
-set -ex
+set -e
 d=/debugfs
 mkdir -p "$d"
-# We also added a fstab entry that mounts this under /sys/kernel/debug autmoatically.
-# That is the most common place to mount it.
-# The /sys/kernel/debug directory gets created automatically when debugfs is
-# compiled into the kernel, but it does not get mounted automatically.
-mount -t debugfs none /debugfs
+mount -t debugfs none "$d"
 insmod /debugfs.ko
-cd "${d}/lkmc_debugfs"
-
-cat myfile
-# => 42
-
-echo 13 > myfile
-cat myfile
-# => 13
-
+[ "$(cat "${d}/lkmc_debugfs/myfile")" = 42 ]
+echo 13 > "${d}/lkmc_debugfs/myfile"
+[ "$(cat "${d}/lkmc_debugfs/myfile")" = 13 ]
 echo 666 > "${d}/lkmc_debugfs_file"
-cat myfile
-# => 666
+[ "$(cat "${d}/lkmc_debugfs/myfile")" = 666 ]
+rmmod debugfs
+umount "$d"