init: disable all userland processes started from init

In order to make the system easier to understand.

These include:

* networking
* klogd and syslogd. TODO what are those for? I could not see anything useful that they do.

Also get rid of the useless S20random thing while we are at it.

rootfs_overlay/etc/init.d/S40network

@@ -1,44 +0,0 @@
-#!/bin/sh
-
-# Copied from: package/ifupdown-scripts/S40network at
-# 8ce27bb9fee80a406a4199657ef90e3c315e7457
-#
-# We then just added this line to turn it off at runtime.
-#
-# We also considered copying the file at build to / and then
-# sourcing it from S98 to be a bit DRYer, but it wouldn't work
-# very well if some S50 requires networking to work.
-#
-# This became necessary nitially when aarch64 qemu and gem5
-# started using the same Buildroot output directory.
-[ -n "$lkmc_nonet" ] && exit 0
-
-#
-# Start the network....
-#
-
-# Debian ifupdown needs the /run/network lock directory
-mkdir -p /run/network
-
-case "$1" in
-  start)
-	printf "Starting network: "
-	/sbin/ifup -a
-	[ $? = 0 ] && echo "OK" || echo "FAIL"
-	;;
-  stop)
-	printf "Stopping network: "
-	/sbin/ifdown -a
-	[ $? = 0 ] && echo "OK" || echo "FAIL"
-	;;
-  restart|reload)
-	"$0" stop
-	"$0" start
-	;;
-  *)
-	echo "Usage: $0 {start|stop|restart}"
-	exit 1
-esac
-
-exit $?
-

rootfs_overlay/rand_check_poweroff.sh

@@ -3,16 +3,8 @@ set -ex
 /rand_check.out
 
 # Check if network is being replayed.
-#
-# TODO; requires internet to be up, which is done by inittab.
-# We could do this with a /etc/init.d/SXX file,
-# but how to both check that into git, and make it optional?
-#
 # https://superuser.com/questions/635020/how-to-know-current-time-from-internet-from-command-line-in-linux
-# Raw IP because was failing with hostname:
-# https://unix.stackexchange.com/questions/124283/busybox-ping-ip-works-but-hostname-nslookup-fails-with-bad-address
 # https://tf.nist.gov/tf-cgi/servers.cgi
-#
 #echo | nc 129.6.15.28 13
 
 # busybox's poweroff panics, TODO why. Likely tries to kill shell.