Setup script to run Steam on Chromebook using a library on an external SD card.

steam.sh

#!/bin/bash

set -o nounset

# 2016-01-02 updated to use whichever device the card is mounted on.
# 2016-07-28 update to use ext4 or fuseblk

# Params
#--------------------------------------------------------------------
# 1. where ChromeOS mounts your SD card
sd_mount="/var/host/media/removable/SD Card"
# 2. where you want to mount your card with custom flags
custom_sd_mount="/home/air/sdcard"
# 3. replace ext4 as appropriate with one of: vfat,fuseblk
sd_format="ext4"

# Derived params
#--------------------------------------------------------------------
default_mount="${sd_mount}/steamapps"
home_mount="${custom_sd_mount}/steamapps"

# Clean up orphaned mounts
#--------------------------------------------------------------------
mount | grep "${custom_sd_mount}" >/dev/null
if [[ $? -eq 0 ]]; then
  # Our custom mount is in the mount table. Check if we can 'ls' in it
  ls ${custom_sd_mount} >/dev/null 2>&1
  if [[ ! $? -eq 0 ]]; then
    echo "Orphaned mount detected: ${custom_sd_mount}"
    umount ${custom_sd_mount}
    if [[ $? -eq 0 ]]; then
      echo "Unmount succeeded for ${custom_sd_mount}"
    else
      echo "Unmount failed, run with sudo"
      exit 5
    fi
  fi
fi

# Set up the normal mount if needed, since Chrome 38 removed automounting of ext4.
# https://code.google.com/p/chromium/issues/detail?id=315401
# After Chrome 38 this is unused, the "SD Card" mount will be present.
#--------------------------------------------------------------------
# mount | grep "${sd_mount}" >/dev/null
# if [[ ! $? -eq 0 ]]; then
#   echo "Could not find default SD mount ${sd_mount}, mounting"
#   mount ${sd_device} "${sd_mount}"
#   if [[ ! $? -eq 0 ]]; then
#     echo "Abort, failed to mount card."
#     exit 1
#   fi
#   mount_proof=$(mount | grep ${sd_device})
#   echo "Mounted SD as ${mount_proof}"
# fi

# If SD card is plugged in, get the device name
#--------------------------------------------------------------------
card_mount=`mount | grep "${sd_mount}"`
if [[ -z "${card_mount}" ]]; then
  echo "Abort: Could not find SD device ${sd_mount}, card not plugged in"
  exit 6
fi
sd_device=`echo ${card_mount} | cut -f1 -d' '`
echo "SD device is ${sd_device}"

# check Steam and make our custom mount if needed
#--------------------------------------------------------------------
if [[ ! -d "${default_mount}" ]]; then
  echo "Abort: Could not find Steam in default location ${default_mount}"
  exit 3
fi

if [[ ! -d "${home_mount}" ]]; then
  # mount SD card in home dir with exec permissions
  mount -t ${sd_format} -o defaults,nosuid,nodev ${sd_device} ${custom_sd_mount}
  if [[ ! -d "${home_mount}" ]]; then
    echo "Abort: Executed mount with type ${sd_format} but can't find home mount ${home_mount}"
    exit 4
  else
    echo "SteamApps is now mounted to ${home_mount}"
  fi
fi