1 files changed, 52 insertions, 0 deletions
diff --git a/files/firstboot/22-expandroot.sh b/files/firstboot/22-expandroot.sh
new file mode 100644
index 0000000..00b94af
--- /dev/null
+++ b/files/firstboot/22-expandroot.sh
@@ -0,0 +1,52 @@
+logger -t "rc.firstboot" "Expanding root"
+ROOT_PART=$(mount | sed -n 's|^/dev/\(.*\) on / .*|\1|p')
+PART_NUM=$(echo ${ROOT_PART} | grep -o '[1-9][0-9]*$')
+case "${ROOT_PART}" in
+  mmcblk0*) ROOT_DEV=mmcblk0 ;;
+  sda*)     ROOT_DEV=sda ;;
+esac
+if [ "$PART_NUM" = "$ROOT_PART" ]; then
+  logger -t "rc.firstboot" "$ROOT_PART is not an SD card. Don't know how to expand"
+  return 0
+fi
+
+# NOTE: the NOOBS partition layout confuses parted. For now, let's only
+# agree to work with a sufficiently simple partition layout
+if [ "$PART_NUM" -gt 2 ]; then
+  logger -t "rc.firstboot" "Your partition layout is not currently supported by this tool."
+  return 0
+fi
+LAST_PART_NUM=$(parted /dev/${ROOT_DEV} -ms unit s p | tail -n 1 | cut -f 1 -d:)
+if [ $LAST_PART_NUM -ne $PART_NUM ]; then
+  logger -t "rc.firstboot" "$ROOT_PART is not the last partition. Don't know how to expand"
+  return 0
+fi
+
+# Get the starting offset of the root partition
+PART_START=$(parted /dev/${ROOT_DEV} -ms unit s p | grep "^${PART_NUM}" | cut -f 2 -d: | sed 's/[^0-9]//g')
+[ "$PART_START" ] || return 1
+
+# Get the possible last sector for the root partition
+PART_LAST=$(fdisk -l /dev/${ROOT_DEV} | grep '^Disk.*sectors' | awk '{ print $7 - 1 }')
+[ "$PART_LAST" ] || return 1
+
+# Return value will likely be error for fdisk as it fails to reload the
+# partition table because the root fs is mounted
+### Since rc.local is run with "sh -e", let's add "|| true" to prevent premature exit
+fdisk /dev/${ROOT_DEV} <<EOF2 || true
+p
+d
+$PART_NUM
+n
+p
+$PART_NUM
+$PART_START
+$PART_LAST
+p
+w
+EOF2
+
+# Reload the partition table, resize root filesystem then remove resizing code from this file
+partprobe &&
+  resize2fs /dev/${ROOT_PART} &&
+  logger -t "rc.firstboot" "Root partition successfuly resized."