update-nvflash |   46 ++++++++++++++++++++++------------------------
 1 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/update-nvflash b/update-nvflash
index 843d62f..9bb0f4e 100755
--- a/update-nvflash
+++ b/update-nvflash
@@ -1,28 +1,27 @@
-#!/bin/bash 
+#!/bin/sh -efu
 #
 
-mydir=${0%/*}
-tmpdir=/var/tmp/nvflash.$$
+mydir=/usr/share/update-nvflash
+tmpdir="$(mktemp -dt "update-nvflash.XXXXXXXXXX")"
 archive=tegra-linux.tar.gz
 
 source $mydir/files.conf
 
 
-function nvflash_check ()
+nvflash_check ()
 {
     test -e /usr/bin/nvflash || return 1
     echo "$nvflash_sum  /usr/bin/nvflash" | md5sum --quiet -c - || return 1 
 
-    test -e /usr/lib/nvflash/bootloader.bin || return 1
-    echo "$bootloader_sum  /usr/lib/nvflash/bootloader.bin" | md5sum --quiet -c - || return 1
+    test -f /usr/lib/nvflash/fastboot.bin || return 1
+    echo "$bootloader_sum  /usr/lib/nvflash/fastboot.bin" | md5sum --quiet -c - || return 1
 
     return 0
 }
 
 
-function nvflash_download ()
+nvflash_download ()
 {
-    mkdir -p $tmpdir
     if [[ $archive_url == file:* ]]; then
         cp ${archive_url#file:} $tmpdir/$archive
     else
@@ -32,7 +31,7 @@ function nvflash_download ()
 }
 
 
-function  nvflash_run_extract ()
+nvflash_run_extract ()
 {
     tar xf $tmpdir/$archive -C $tmpdir
     echo "$nvflash_sum  $tmpdir/ldk/bootloader/nvflash" | md5sum --quiet -c - || exit 1
@@ -40,30 +39,31 @@ function  nvflash_run_extract ()
 }
 
 
-function nvflash_install ()
+nvflash_install ()
 {
-    install -p $tmpdir/ldk/bootloader/nvflash /usr/bin/
-    install -p $tmpdir/ldk/bootloader/harmony/fastboot.bin /usr/lib/nvflash/
+    install -m0755 -D $tmpdir/ldk/bootloader/nvflash /usr/bin/nvflash
+    install -m0644 -D $tmpdir/ldk/bootloader/harmony/fastboot.bin /usr/lib/nvflash/fastboot.bin
 }
 
 
-function nvflash_clean ()
+nvflash_clean ()
 {
-    rm -rf $tmpdir
+    rm -rf "$tmpdir"
 }
+trap nvflash_clean EXIT
+trap nvflash_clean HUP PIPE INT QUIT TERM
 
 
-function nvflash_remove ()
+nvflash_remove ()
 {
-    rm -f /usr/bin/nvflash
-    rm -f /usr/lib/nvflash/bootloader.bin
+    rm /usr/bin/nvflash || :
+    rm /usr/lib/nvflash/fastboot.bin || :
 }
 
 
-function nvflash_update ()
+nvflash_update ()
 {
-    nvflash_check 
-    test $? = 0 && return
+    nvflash_check && return
 
     nvflash_download
     nvflash_run_extract
@@ -72,8 +72,7 @@ function nvflash_update ()
 }
 
 
-
-case "$1" in
+case "${1:---help}" in
     --install)
         nvflash_update
         ;;
@@ -81,8 +80,7 @@ case "$1" in
         nvflash_remove
         ;;
     --check)
-        nvflash_check
-        if [ $? = 0 ]; then
+        if nvflash_check; then
             echo "nvflash: installed - ok"
         else
             echo "nvflash: need to be installed or updated"