#!/bin/bash

# Wrapper around run-environment.sh that sets up writeable space for /home
# and distcc acceleration (if the cross compiler and distcc are available).

# The following environment variables affect the behavior of this script:

# HDB - Image file to use for -hdb on /home (none if blank)
# HDBMEGS - Number of megabytes to create
# HDC - Image file to use for -hdc on /mnt (none of blank)
# QEMU_MEMORY - number of megabytes of memory for qemu (defaults to 128)

# Also, to use the distcc accelerator you need to have distccd and $ARCH-cc
# in the $PATH.

INCLUDE unique-port.sh
INCLUDE make-hdb.sh

source ./run-emulator.sh --norun || exit 1

[ -z "$QEMU_MEMORY" ] && QEMU_MEMORY=256
QEMU_EXTRA="-m $QEMU_MEMORY $QEMU_EXTRA"

# Should we set up an ext3 image as a second virtual hard drive for /home?

if [ "$HDBMEGS" != "0" ]
then
  [ -z "$HDB" ] && HDB=hdb.img
  if [ ! -e "$HDB" ]
  then

    # If we don't already have an hdb image, should we set up a sparse file and
    # format it ext3?

    [ -z "$HDBMEGS" ] && HDBMEGS=2048

    make_hdb
  fi
fi

# Setup distcc

# If the cross compiler isn't in the $PATH, look for it in the current
# directory, the parent directory, and the user's home directory.

DISTCC_PATH="$(which $ARCH-cc 2>/dev/null | sed 's@\(.*\)/.*@\1@')"

if [ -z "$DISTCC_PATH" ]
then
  for i in {"$(pwd)/","$(pwd)/../","$HOME"/}{,simple-}cross-compiler-"$ARCH"/bin
  do
    [ -f "$i/$ARCH-cc" ] && DISTCC_PATH="$i" && break
  done
fi

[ -z "$(which distccd)" ] && [ -e ../host/distccd ] &&
  PATH="$PATH:$(pwd)/../host"

[ -z "$CPUS" ] && CPUS=1
if [ -z "$(which distccd)" ]
then
  echo 'No distccd in $PATH, acceleration disabled.'
elif [ -z "$DISTCC_PATH" ]
then
  echo "No $ARCH-cc in "'$PATH'", acceleration disabled."
else

  # Populate a directory full of symlinks to the cross compiler using the
  # unprefixed names distccd will try to use.

  mkdir -p "distcc_links" &&
  for i in $(cd "$DISTCC_PATH"; ls $ARCH-* | sed "s/^$ARCH-//" )
  do
    ln -sf "$DISTCC_PATH/$ARCH-$i" "distcc_links/$i"
  done
  if [ -e "$DISTCC_PATH/$ARCH-rawgcc" ]
  then
    for i in cc gcc g++ c++
    do
      ln -sf "$DISTCC_PATH/$ARCH-rawgcc" distcc_links/$i
    done
  fi

  # Run the distcc daemon on the host system with $PATH restricted to the
  # cross compiler binaries.

  # Note that we tell it --no-detach and background it ourselves so jobs -p can
  # find it later to kill it after the emulator exits.

  PORT=$(unique_port)
  if [ -z "$CPUS" ]
  then
    # Current parallelism limits include:
    #   - memory available to emulator (most targets max at 256 megs, which
    #     gives about 80 megs/instance).
    #   - speed of preprocessor (tcc -E would be faster than gcc -E)
    #   - speed of virtual network (switch to virtual gigabit cards).
    #
    # CPUS=$[$(echo /sys/devices/system/cpu/cpu[0-9]* | wc -w)*2]
    CPUS=3
  fi
  PATH="$(pwd)/distcc_links" "$(which distccd)" --no-detach --daemon \
    --listen 127.0.0.1 -a 127.0.0.1 -p $PORT --jobs $CPUS \
    --log-stderr --verbose 2>distccd.log &

  # Clean up afterwards: Kill child processes we started (I.E. distccd).
  trap "kill $(jobs -p)" EXIT

  # When background processes die, they should do so silently.
  disown $(jobs -p)

  # Let the QEMU launch know we're using distcc.

  DISTCC_PATH_PREFIX=/usr/distcc:
  KERNEL_EXTRA="DISTCC_HOSTS=10.0.2.2:$PORT/$CPUS $KERNEL_EXTRA"
fi

KERNEL_EXTRA="CPUS=$CPUS $KERNEL_EXTRA"

# Kill our child processes on exit.

trap "pkill -P$$" EXIT

# The actual emulator invocation command gets appended here by system-image.sh

[ ! -z "$HDC" ] && QEMU_EXTRA="-hdc $HDC $QEMU_EXTRA"
[ ! -z "$HDB" ] && QEMU_EXTRA="-hdb $HDB $QEMU_EXTRA"

run_emulator