Separate files into those used for setup and those used at runtime.

Files used for both will go in the run tree.

setup/macos_linux/setup-piForHeadlessConfig.sh

@@ -0,0 +1,98 @@
+#/bin/bash -eu
+
+# This script will modify the cmdline.txt file on a freshly flashed Raspbian Stretch/Lite
+# It readies it for SSH, USB OTG, USB networking, and Wifi
+#
+# Pass it the path to the location at which the "boot" filesystem is mounted.
+# E.g. on a Mac:
+#   ./setup-piForHeadlessConfig.sh /Volumes/boot
+# or on Ubuntu:
+#   ./setup-piForHeadlessConfig.sh /media/$USER/boot
+# cd /Volumes/boot (or wherever the boot folder is mounted)
+# chmod +x setup-piForHeadlessConfig.sh
+# ./setup-piForHeadlessConfig.sh
+#
+# Put the card in your Pi, and reboot!
+
+# Creates the ssh file if needed, since Raspbian now disables 
+# ssh by default if the file isn't present
+
+BOOT_DIR="$1"
+
+function verify_file_exists () {
+  local file_name="$1"
+  local expected_path="$2"
+  
+  if [ ! -e "$expected_path/$file_name" ]
+    then
+      echo "STOP: Didn't find $file_name at $expected_path."
+      exit 1
+  fi  
+}
+
+function verify_wifi_variables () {
+  if [ ! -n "${SSID+x}" ] || [ ! -n "${WIFIPASS+x}"  ]
+  then
+    echo 'STOP: You need to specify your wifi name and password first. Run: '
+    echo " "
+    echo '      export SSID=your_ssid'
+    echo '      export WIFIPASS=your_wifi_password'
+    echo " "
+    echo "Be sure to replace the values with your SSID (network name) and password."
+    exit 1
+  fi
+}
+
+verify_file_exists "cmdline.txt" "$BOOT_DIR"
+verify_file_exists "config.txt" "$BOOT_DIR"
+
+verify_wifi_variables
+
+CMDLINE_TXT_PATH="$BOOT_DIR/cmdline.txt"
+CONFIG_TXT_PATH="$BOOT_DIR/config.txt"
+
+if ! grep -q "dtoverlay=dwc2" $CONFIG_TXT_PATH
+then
+   echo "Updating $CONFIG_TXT_PATH ..."
+   echo "" >> "$CONFIG_TXT_PATH"
+   echo "dtoverlay=dwc2" >> "$CONFIG_TXT_PATH"
+else
+   echo "$CONFIG_TXT_PATH already contains the required dwc2 module"
+fi
+
+if ! grep -q "dwc2,g_ether" $CMDLINE_TXT_PATH
+then
+  echo "Updating $CMDLINE_TXT_PATH ..."
+  sed -i'.bak' -e "s/rootwait/rootwait modules-load=dwc2,g_ether/" -e "s@ init=/usr/lib/raspi-config/init_resize.sh@@" "$CMDLINE_TXT_PATH"
+else
+  echo "$CMDLINE_TXT_PATH already updated with modules and removed initial resize script."
+fi
+
+echo "Enabling SSH ..."
+touch "$BOOT_DIR/ssh"
+
+# Sets up wifi credentials so wifi will be 
+# auto configured on first boot
+
+WPA_SUPPLICANT_CONF_PATH="$BOOT_DIR/wpa_supplicant.conf"
+
+echo "Adding Wifi setup file (wpa_supplicant.conf)."
+if [ -r "$WPA_SUPPLICANT_CONF_PATH" ]
+then
+  rm "$WPA_SUPPLICANT_CONF_PATH"
+fi
+
+cat << EOF >> "$WPA_SUPPLICANT_CONF_PATH"
+ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
+update_config=1
+
+network={
+  ssid="$SSID"
+  psk="$WIFIPASS"
+  key_mgmt=WPA-PSK
+}
+EOF
+
+echo ""
+echo '-- Files updated and ready for Wifi and SSH over USB --'
+echo ""