Enable booting from sata on A20 boards

src/freedombone-image

 MBR_REPO="https://aur.archlinux.org/mbr.git"
 CLIAPP_REPO="git://git.liw.fi/cliapp"
 
+# Whether to use a SATA drive and if so what its device/partition name is
+# eg. sda2
+EXTERNAL_DRIVE=
+
 function image_setup {
     setup_type=$1
 
             shift
             LOCAL_NAME="$1"
             ;;
+        --sata|--hdd)
+            shift
+            EXTERNAL_DRIVE="$1"
+            ;;
         *)
             # unknown option
             ;;
      INSECURE="$INSECURE" \
      AMNESIC="$AMNESIC" \
      SOCIALINSTANCE="$SOCIALINSTANCE" \
+     EXTERNAL_DRIVE="$EXTERNAL_DRIVE" \
      LOCAL_NAME="$LOCAL_NAME"
 
 # shellcheck disable=SC2181

src/freedombone-image-customise

 
 PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin
 
+# Whether to use a SATA drive and if so what its device/partition name is
+# eg. sda2
+EXTERNAL_DRIVE=
+
 configure_backports() {
     echo "deb http://${DEBIAN_REPO}/debian/ ${DEBIAN_VERSION}-backports main" >> "$rootdir/etc/apt/sources.list"
 }

src/freedombone-image-hardware-setup

 
 a20_setup_boot() {
     dtb="$1"
+    a20_root_device='mmcblk0p2'
+    if [ "$2" ]; then
+        a20_root_device="$2"
+    fi
 
     # Setup boot.cmd
     if grep -q btrfs /etc/fstab ; then
 setenv mmcdev 0
 setenv mmcpart 1
 
-setenv mmcroot /dev/mmcblk0p2 ro
+setenv mmcroot /dev/${a20_root_device} ro
 setenv mmcrootfstype $fstype rootwait fixrtc
 setenv mmcrootflags subvol=@
 
         enable_serial_console ttyO0
         ;;
     cubietruck)
-        a20_setup_boot sun7i-a20-cubietruck.dtb
+        a20_setup_boot sun7i-a20-cubietruck.dtb "$EXTERNAL_DRIVE"
         enable_serial_console ttyS0
         ;;
     a20-olinuxino-lime)
-        a20_setup_boot sun7i-a20-olinuxino-lime.dtb
+        a20_setup_boot sun7i-a20-olinuxino-lime.dtb "$EXTERNAL_DRIVE"
         enable_serial_console ttyS0
         ;;
     a20-olinuxino-lime2)
-        a20_setup_boot sun7i-a20-olinuxino-lime2.dtb
+        a20_setup_boot sun7i-a20-olinuxino-lime2.dtb "$EXTERNAL_DRIVE"
         enable_serial_console ttyS0
         ;;
     a20-olinuxino-micro)
-        a20_setup_boot sun7i-a20-olinuxino-micro.dtb
+        a20_setup_boot sun7i-a20-olinuxino-micro.dtb "$EXTERNAL_DRIVE"
         enable_serial_console ttyS0
         ;;
     cubieboard2)
-        a20_setup_boot sun7i-a20-cubieboard2.dtb
+        a20_setup_boot sun7i-a20-cubieboard2.dtb "$EXTERNAL_DRIVE"
         enable_serial_console ttyS0
         ;;
     pcduino3)
-        a20_setup_boot sun7i-a20-pcduino3.dtb
+        a20_setup_boot sun7i-a20-pcduino3.dtb "$EXTERNAL_DRIVE"
         enable_serial_console ttyS0
         ;;
 esac

src/freedombone-image-make

 export AMNESIC
 export SOCIALINSTANCE
 export LOCAL_NAME
+export EXTERNAL_DRIVE
 
 # Locate vmdebootstrap program fetched in Makefile
 basedir=`pwd`
 sed -i "s|AMNESIC=.*|AMNESIC=\"${AMNESIC}\"|g" "$TEMP_CUSTOMISE3"
 sed -i "s|SOCIALINSTANCE=.*|SOCIALINSTANCE=\"${SOCIALINSTANCE}\"|g" "$TEMP_CUSTOMISE3"
 sed -i "s|LOCAL_NAME=.*|LOCAL_NAME=\"${LOCAL_NAME}\"|g" "$TEMP_CUSTOMISE3"
+sed -i "s|EXTERNAL_DRIVE=.*|EXTERNAL_DRIVE=\"${EXTERNAL_DRIVE}\"|g" "$TEMP_CUSTOMISE3"
 sed -i 's|#!/bin/bash||g' "$TEMP_CUSTOMISE3"
 
 cat $TEMP_CUSTOMISE2 $TEMP_CUSTOMISE3 > $TEMP_CUSTOMISE4