Add dynamic USB device detection

Instead of relying on a hard-coded USB disk, it would be better if the
mount script attempted to dynamically detect available USB disks. This
modification to the USB mount script attempts to handle the common case
of a single USB disk but can also handle the case of multiple disks
where it will present the user with all available USB disks

initrd/bin/flash-gui.sh

@@ -70,10 +70,10 @@ file_selector() {
 
 while true; do
   unset menu_choice
-  whiptail --clear --title "BIOS Management Menu" \
-    --menu 'Select the BIOS function to perform' 20 90 10 \
-    'f' ' Flash the BIOS with a new ROM' \
-    'c' ' Flash the BIOS with a new cleaned ROM' \
+  whiptail --clear --title "Firmware Management Menu" \
+    --menu "Select the firmware function to perform\n\nRetaining settings copies existing settings to the new firmware:\n* Keeps your GPG keyring\n* Keeps changes to the default /boot device\n\nErasing settings uses the new firmware as-is:\n* Erases any existing GPG keyring\n* Restores firmware to default factory settings\n\nIf you are just updating your firmware, you probably want to retain\nyour settings." 20 90 10 \
+    'f' ' Flash the firmware with a new ROM, retain settings' \
+    'c' ' Flash the firmware with a new ROM, erase settings' \
     'x' ' Exit' \
     2>/tmp/whiptail || recovery "GUI menu failed"
 
@@ -104,7 +104,7 @@ while true; do
               /bin/flash.sh "$ROM"
             fi
             whiptail --title 'ROM Flashed Successfully' \
-              --msgbox "$ROM flashed successfully. Press Enter to reboot" 16 60
+              --msgbox "$ROM flashed successfully.\nPress Enter to reboot" 16 60
             umount /media
             /bin/reboot
           else