Fix inittab back to adding /proc, fops sketch, scripts to automate debugfs

rootfs_overlay/debugfs.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+set -ex
+mkdir -p /debugfs
+mount -t debugfs none /debugfs
+insmod /debugfs.ko
+cd /debugfs/kernel_module_cheat
+cat myfile
+# => 42

rootfs_overlay/etc/inittab

@@ -1,3 +1,14 @@
 # /etc/inittab
+::sysinit:/bin/mount -t proc proc /proc
+::sysinit:/bin/mount -o remount,rw /
+::sysinit:/bin/mkdir -p /dev/pts
+::sysinit:/bin/mkdir -p /dev/shm
+::sysinit:/bin/mount -a
+::sysinit:/bin/hostname -F /etc/hostname
+::sysinit:/etc/init.d/rcS
 # https://unix.stackexchange.com/questions/299408/how-to-login-automatically-without-typing-root-in-buildroot-x86-64-qemu
 console::respawn:/bin/sh
+::ctrlaltdel:/sbin/reboot
+::shutdown:/etc/init.d/rcK
+::shutdown:/sbin/swapoff -a
+::shutdown:/bin/umount -a -r

rootfs_overlay/fops.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -ex
+insmod /fops.ko
+mkdir -p /fops
+mount -t debugfs none /fops
+cd /fops/kernel_module_cheat
+cat fops
+# => open
+# => read
+# => close
+# TODO.
+#echo a >fops