User setup and erlang installation

A bit fiddly, but this lets us run a realistic erlang install script
from userspace, and then re-enter userspace later without wiping the
installation.

debian/create_environment

@@ -17,14 +17,6 @@ else
     ./get_debootstrap --arch i386 sid "$FRESH" http://deb.debian.org/debian/
 fi
 
-cleanup_mount() {
-    if mountpoint "$1" > /dev/null
-    then
-        echo "Unmounting $1"
-        umount "$1"
-    fi
-}
-
 if test -e "$ROOT"
 then
     echo "Existing installation found at $ROOT, removing."
@@ -35,8 +27,14 @@ echo "Copying $FRESH to $ROOT."
 cp -r "$FRESH" "$ROOT"
 
 echo "Initializing $ROOT."
-mkdir -p "$ROOT/proc"
-mount proc $ROOT/proc -t proc
-mkdir -p "$ROOT/sys"
-mount sysfs $ROOT/sys -t sysfs
 
+./mountpoints
+
+# Don't bother creating a new tmpfs. We don't want to leak files in, and we
+# don't want to waste more RAM on a second tmpfs. The whole thing is
+# temporary, after all.
+chmod 1777 "$ROOT/tmp"
+
+cp -r install_scripts "$ROOT/root"
+
+chroot "$ROOT" /root/install_scripts/user_setup "$@"