#!/bin/sh

# Paranoia.
case "$ZSH_VERSION" in ?*) alias -g '${1+"$@"}'='"$@"';; esac
s_=; try_=; x_=
unset s_ try_ x_

# Do something, and spawn an interactive shell if it fails.
try_() {
  echo "$@"
  "$@"
  s_="$?"
  case "$s_" in 0) return 0;; esac
  echo "This command: $*
returned $s_.  Please fix it.  After you exit this shell, I'll continue
booting, but I won't retry that command."
  while :; do
    s_="$s_" /bin/sh && return 0
  done
  sync
}

SUPERVISE_ENV=/package/admin/svclean-conf/supervise-env

init_step_0_() {
  try_ umask 022

  # Load the global $PATH value.
  try_ eval 'read PATH < "$SUPERVISE_ENV"/PATH'
  try_ export PATH

  # We booted with a disk filesystem as root, but we're going to switch to
  # tmpfs as root.  Mount the tmpfs filesystem.
  try_ fsmount temp
  # /fs has to be copied onto tmpfs, because it's the configuration of all
  # other filesystems.  Everything else can be symlinked.
  try_ tar --one-file-system -cf fs/temp/mount/fs.tar fs
  # Unpack the copy and remove the tarball.
  try_ cd fs/temp/mount
  try_ tar xf fs.tar
  try_ rm -f  fs.tar
  # Move the symlinks for top-level directories into place.
  try_ mv -f fs/temp/root/* .
  try_ rmdir fs/temp/root
  # Adjust the tmpfs copy of the filesystem configurations: tmpfs is going to
  # be the new root, and pkgs is going to be a non-root filesystem.
  try_ rmdir      fs/temp/mount
  try_ ln -s /.   fs/temp/mount
  try_ rm -f      fs/std-root
  try_ ln -s temp fs/std-root
  try_ rm -f      fs/pkgs/mount
  try_ mkdir      fs/pkgs/mount

  # Set the current-version symlink for the kernel so we can find modules.
  try_ eval 'x_=`dirname "$BOOT_FILE"`'
  try_ eval 'x_=`dirname "$x_"`'
  try_ ln -s "$x_" /fs/temp/mount/tmp/linux

  # Shuffle filesystems, set UID/GID, set environment, and do the next step.
  exec \
    pivotchroot . fs/pkgs/mount \
    setuidgid root \
    envdir "$SUPERVISE_ENV" \
    env init_step_=1 \
    "$0" ${1+"$@"}
}

init_step_1_() {
  try_ unset init_step_

  fsck=${fsck-y}
  intervene=${intervene-n}

  # Check the disk filesystem that was the original root.
  [ "$fsck" = n ] || try_ fscheck pkgs
  try_ fsmount pkgs remount

  # Set up the console keymap.
  try_ eval 'loadkeys /etc/console.kmap > /dev/tty1'
  try_ setfont lat1-08

  # Set up important /proc stuff early.
  try_ fsmount proc
  try_ eval 'echo 0              > /proc/sys/kernel/ctrl-alt-del'
  try_ eval 'echo 0              > /proc/sys/kernel/sysrq || :'
  try_ eval 'echo "$HOSTNAME"    > /proc/sys/kernel/hostname'
  try_ eval 'cat /etc/domainname > /proc/sys/kernel/domainname'

  # Check and mount other filesystems.
  try_ fsmount ptys
  try_ fsmount sysf
  [ "$fsck" = n ] || try_ fscheck logs
  try_ fsmount logs
  [ "$fsck" = n ] || try_ fscheck home
  try_ fsmount home

  # Another way to measure uptime.
  try_ touch /var/lastboot

  # Set the kernel's log verbosity.
  try_ dmesg -n 1

  # Adjust the date.  hwclock doesn't grok TAI clocks.
  try_ hwclock --hctosys --utc
  case $TZ in
    right/*)
      try_ eval 'dt=`date "+%Y-%m-%d %H:%M:%S"`'
      try_ eval 't0=`TZ=America/New_York       date -d "$dt" +%s`'
      try_ eval 't1=`TZ=right/America/New_York date -d "$dt" +%s`'
      try_ eval 'tdiff=`expr "$t1" - "$t0"`'
      try_ date -s "+$tdiff seconds";;
    *) :;;
  esac

  # Activate swap areas.
  for x_ in /package/host/code.dogmap.org/foreign/linux-data/swap-*; do
    try_ minswapon "$x_"
  done

  # Now that we have swap, disable memory overcommitment.
  try_ eval 'echo 2 > /proc/sys/vm/overcommit_memory'
  try_ eval 'echo 0 > /proc/sys/vm/overcommit_ratio'

  # Initialize the login records.
  try_ eval ': > /var/run/utmp'
  try_ touch /var/log/wtmp

  # Set up networking parameters.
  #ry_ eval 'echo 1 > /proc/sys/net/ipv4/ip_forward'
  try_ eval 'echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter'
  try_ eval 'echo 1 > /proc/sys/net/ipv4/conf/default/rp_filter'
  try_ eval 'echo 1 > /proc/sys/net/ipv4/tcp_syncookies'

  try_ modprobe /dev/mouse

  # Set up sound.
  try_ modprobe /dev/mixer
  try_ aumix -v83 -w100 -p75 -c100

  # Load and then save the entropy pool.
  try_ dd if=/package/host/code.dogmap.org/foreign/linux-data/entropy-pool \
          of=/dev/urandom
  try_ dd if=/dev/urandom \
          of=/package/host/code.dogmap.org/foreign/linux-data/entropy-pool \
          bs=4096 count=1

  # Set up the loopback network.
  try_ ifconfig lo    127.0.0.1 netmask 255.0.0.0 broadcast 127.255.255.255
  try_ route add -net 127.0.0.0 netmask 255.0.0.0 dev lo

  # Make sure services will come up.
  try_ rm -f /service/*/svclean/shutdown /service/*/log/svclean/shutdown

  # If there's something to be done before the system comes completely up,
  # this is the last chance.
  if [ "$intervene" = y ]; then
    echo 'Exiting this shell will resume booting.'
    /bin/sh
  fi

  # Make a copy of svscan so that if we delete the original (e.g., to
  # recompile) we can still remount that filesystem read-only.
  try_ rm -rf /tmp/svscan
  try_ cp -p /command/svscan /tmp/
  (sleep 5 && rm -f /tmp/svscan) &
  exec < /dev/null \
    env - SUPERVISE_ENV="$SUPERVISE_ENV" PATH="$PATH" \
    svclean-svscan \
    /tmp/svscan /service
}

init_step_"${init_step_-0}"_ ${1+"$@"}