move all our stuff into /lkmc in guest

Motivation: userland is getting several new subdirectories, it would be
too insane to just dump all of that in the guest root filesystem.

To alleviate the cd pain, .profile puts user inside /lkmc by default.

rootfs_overlay/.profile

@@ -0,0 +1,4 @@
+# https://github.com/cirosantilli/linux-kernel-module-cheat#busybox-shell-initrc-files
+echo "hello .profile"
+export PS1='\w\n\u@\h# '
+cd /lkmc

rootfs_overlay/conf.sh

@@ -1,2 +0,0 @@
-#!/bin/sh
-zcat /proc/config.gz | grep -Ei "${1:-}"

rootfs_overlay/etc/init.d/S98

@@ -1,5 +1,7 @@
 #!/bin/sh
+# https://github.com/cirosantilli/linux-kernel-module-cheat#init-busybox
 echo "hello S98"
+cd "$lkmc_home"
 if [ -n "$lkmc_eval" ]; then
   eval "$lkmc_eval"
 elif [ -n "$lkmc_eval_base64" ]; then

rootfs_overlay/eval.sh

@@ -1,18 +0,0 @@
-#!/bin/sh
-echo "$lkmc_eval"
-eval "$lkmc_eval"
-
-# Ideally, this script would do just:
-#
-## Get rid of the '-'.
-#shift
-#echo "$@"
-#
-# However, the kernel CLI parsing is crap, and the 4.14 docs lie.
-#
-# In particular, not all that is passed after "-" goes to an argument to init,
-# e.g. stuff with dots like "- ./poweroff.out" still gets treated specially and
-# does not go to init.
-#
-# This also likely means that the above solution is also unreliable in some cases,
-# and that in the end you just have to add a script to the root filesystem.

rootfs_overlay/eval_base64.sh

@@ -1,2 +0,0 @@
-#!/bin/sh
-eval "$(printf "$lkmc_eval" | base64 -d)"

rootfs_overlay/lkmc/conf.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+# https://github.com/cirosantilli/linux-kernel-module-cheat#find-the-kernel-config
+zcat /proc/config.gz | grep -Ei "${1:-}"

rootfs_overlay/lkmc/count.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# Count to infinity with 1 second sleep between each increment.
 # Generate infinitely many system calls :-)
 i=0
 while true; do

rootfs_overlay/lkmc/eval_base64.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+# https://github.com/cirosantilli/linux-kernel-module-cheat#replace-init
+cd "$lkmc_home"
+eval "$(printf "$lkmc_eval" | base64 -d)"

rootfs_overlay/lkmc/loginroot.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+# https://github.com/cirosantilli/linux-kernel-module-cheat#tty
+exec /bin/login root

rootfs_overlay/lkmc/test_all.sh

@@ -20,7 +20,7 @@ for test in \
 ; do
   if ! "${test_dir}/${test}"; then
     echo "Test failed: ${test}"
-    test_fail.sh
+    ./test_fail.sh
     exit 1
   fi
 done

rootfs_overlay/loginroot.sh

@@ -1,2 +0,0 @@
-#!/bin/sh
-exec /bin/login root

rootfs_overlay/root/.profile

@@ -1,4 +0,0 @@
-# https://unix.stackexchange.com/questions/176027/ash-profile-configuration-file
-echo "hello $(pwd)/.profile"
-# Does not inherit init environment variables.
-#env