Only search for the gpt tool if we need it.

src/platform/installer/chromeos-common.sh

 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # This contains common constants and functions for installer scripts. This must
 # evaluate properly for both /bin/bash and /bin/sh, since it's used both to
 # create the initial image at compile time and to install or upgrade a running
 # image.
 
 # Here are the GUIDs we'll be using to identify various partitions. NOTE: The
@@ skipping 63 matching lines @@
   local num=$1
   local div=${2:-4096}
   local rem=$(( $num % $div ))
 
   if [ $rem -ne 0 ]; then
     num=$(($num - $rem))
   fi
   echo $num
 }
 
+# Locate the gpt tool. It should already be installed in the build chroot,
+# but some of these functions may be invoked outside the chroot (by
+# image_to_usb or similar), so we need to find it.
+GPT=""
 
-# We need to locate the gpt tool. It should already be installed in the build
-# chroot, but some of these functions may be invoked outside the chroot (by
-# image_to_usb or similar), so we need to find it.
-GPT=$(which gpt 2>/dev/null) || /bin/true
-if [ -z "$GPT" ]; then
-  if [ -x "${DEFAULT_CHROOT_DIR:-}/usr/bin/gpt" ]; then
-    GPT="${DEFAULT_CHROOT_DIR:-}/usr/bin/gpt"
-  else
-    echo "can't find gpt tool" 1>&2
-    exit 1
+locate_gpt() {
+  if [ -z "$GPT" ]; then
+    GPT=$(which gpt 2>/dev/null) || /bin/true
+    if [ -z "$GPT" ]; then
+      if [ -x "${DEFAULT_CHROOT_DIR:-}/usr/bin/gpt" ]; then
+        GPT="${DEFAULT_CHROOT_DIR:-}/usr/bin/gpt"
+      else
+        echo "can't find gpt tool" 1>&2
+        exit 1
+      fi
+    fi
   fi
-fi
-
+}
 
 # This installs a GPT into the specified device or file, using the given
 # components. If the target is a block device or the FORCE_FULL arg is "true"
 # we'll do a full install. Otherwise, it'll be just enough to boot.
 # Invoke as: command (not subshell)
 # Args: TARGET ROOTFS_IMG KERNEL_IMG STATEFUL_IMG PMBRCODE ESP_IMG FORCE_FULL
 # Return: nothing
 # Side effects: Sets these global variables describing the GPT partitions
 #   (all units are 512-byte sectors):
 #   NUM_ESP_SECTORS
@@ skipping 76 matching lines @@
   local num_kern_c_sectors=1
   local start_rootfs_c=$(($start_kern_c + 1))
   local num_rootfs_c_sectors=1
   local start_future_9=$(($start_rootfs_c + 1))
   local num_future_sectors=1
   local start_future_10=$(($start_future_9 + 1))
   local start_future_11=$(($start_future_10 + 1))
 
   local start_useful=$(roundup $(($start_future_11 + 1)))
 
+  locate_gpt
+
   # What are we doing?
   if [ -b "$outdev" -o "$force_full" = "true" ]; then
     # Block device, need to be root.
     if [ -b "$outdev" ]; then
       local sudo=sudo
     else
       local sudo=""
     fi
 
     # Full install, use max sizes and create both A & B images.
@@ skipping 70 matching lines @@
 
   # Zap any old partitions (otherwise gpt complains).
   $sudo dd if=/dev/zero of=${outdev} conv=notrunc bs=512 \
     count=$num_header_sectors
   $sudo dd if=/dev/zero of=${outdev} conv=notrunc bs=512 \
     seek=${start_gpt_footer} count=$num_footer_sectors
 
   # Create the new GPT partitions. The order determines the partition number.
   # Note that the partition label is in the GPT only. The filesystem label is
   # what's used to populate /dev/disk/by-label/, and this is not that.
+
   $sudo $GPT create ${outdev}
 
   $sudo $GPT add -b ${START_STATEFUL} -s ${NUM_STATEFUL_SECTORS} \
     -t ${DATA_GUID} ${outdev}
   $sudo $GPT label -i 1 -l "STATE" ${outdev}
 
   $sudo $GPT add -b ${START_KERN_A} -s ${num_kern_a_sectors} \
     -t ${KERN_GUID} ${outdev}
   $sudo $GPT label -i 2 -l "KERN-A" ${outdev}
 
@@ skipping 45 matching lines @@
 
   sync
 }
 
 
 # Helper function, please ignore and look below.
 _partinfo() {
   local device=$1
   local partnum=$2
   local start size part x n
+
+  locate_gpt
+
   sudo $GPT -r -S show $device \
     | grep 'GPT part -' \
     | while read start size part x x x n x; do \
         if [ "${part}" -eq "${partnum}" ]; then \
           echo $start $size; \
         fi; \
       done
   # The 'while' is a subshell, so there's no way to indicate success.
 }
 
@@ skipping 108 matching lines @@
   if [ -x "$MKIMAGE" ]; then
     MBR_SCRIPT_UIMG="${MBR_SCRIPT}.uimg"
     "$MKIMAGE" -A "arm" -O linux  -T script -a 0 -e 0 -n "COS boot" \
                -d ${MBR_SCRIPT} ${MBR_SCRIPT_UIMG} >&2
   else
     echo "Error: u-boot mkimage not found or not executable." >&2
     exit 1
   fi
   echo ${MBR_SCRIPT_UIMG}
 }