From 68754ae925efbcf48f7395fcd264912159d43bb9 Mon Sep 17 00:00:00 2001
From: Alex Deryskyba <alex@codesnake.com>
Date: Thu, 28 May 2015 18:18:21 +0200
Subject: [PATCH] packages/sysutils/busybox/scripts/init: Add the ability to
 update the kernel that resides on a block device, such as NAND partition

---
 packages/sysutils/busybox/scripts/init | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/packages/sysutils/busybox/scripts/init b/packages/sysutils/busybox/scripts/init
index 1afea77dfc..0f8bfc5651 100755
--- a/packages/sysutils/busybox/scripts/init
+++ b/packages/sysutils/busybox/scripts/init
@@ -332,7 +332,7 @@
     $MOUNT_CMD "$MOUNT_TARGET" "$2" "$3" "$4"
   }
 
-  update() {
+  update_file() {
     if [ -f "$UPDATE_DIR/$2" -a -f "$3" ]; then
       echo "updating $1..."
       mount -o remount,rw /flash
@@ -345,6 +345,13 @@
     fi
   }
 
+  update_partition() {
+    if [ -f "$UPDATE_DIR/$2" -a -b "$3" ]; then
+      echo "updating $1..."
+      dd if="$UPDATE_DIR/$2" of="$3"
+     fi
+   }
+
   update_bootloader() {
     export BOOT_ROOT="/flash"
     export SYSTEM_ROOT="/sysroot"
@@ -602,7 +609,12 @@
       # get sizes
       FLASH_FREE=$(df /flash/ | awk '/[0-9]%/{print $4}')
       FLASH_FREE=$(( $FLASH_FREE * 1024 ))
-      OLD_KERNEL=$(stat -t "/flash/$IMAGE_KERNEL" | awk '{print $2}')
+
+      OLD_KERNEL="0"
+      if [ ! -b $IMAGE_KERNEL ]; then
+        OLD_KERNEL=$(stat -t "/flash/$IMAGE_KERNEL" | awk '{print $2}')
+      fi
+
       OLD_SYSTEM=$(stat -t "/flash/$IMAGE_SYSTEM" | awk '{print $2}')
       NEW_KERNEL=$(stat -t "$UPDATE_DIR/$UPDATE_KERNEL" | awk '{print $2}')
       NEW_SYSTEM=$(stat -t "$UPDATE_DIR/$UPDATE_SYSTEM" | awk '{print $2}')
@@ -624,8 +636,12 @@
       if [ "$SIZE_FAILED" -eq "0" ] ; then
         # update if md5 check is ok or .nocheck exists
         if [ "$MD5_FAILED" -eq "0" -o "$MD5_NOCHECK" -eq "1" ] ; then
-          update "Kernel" "$UPDATE_KERNEL" "/flash/$IMAGE_KERNEL"
-          update "System" "$UPDATE_SYSTEM" "/flash/$IMAGE_SYSTEM"
+          if [ -b $IMAGE_KERNEL ]; then
+            update_partition "Kernel" "$UPDATE_KERNEL" "$IMAGE_KERNEL"
+          else
+            update_file "Kernel" "$UPDATE_KERNEL" "/flash/$IMAGE_KERNEL"
+          fi
+          update_file "System" "$UPDATE_SYSTEM" "/flash/$IMAGE_SYSTEM"
           update_bootloader
           rm -rf $UPDATE_DIR/[0-9a-zA-Z]* &>/dev/null
           do_reboot