diff --git a/board/common/overlay/etc/init.d/S14postupgrade b/board/common/overlay/etc/init.d/S14postupgrade
index 65c0adf96b..bb41a4e105 100755
--- a/board/common/overlay/etc/init.d/S14postupgrade
+++ b/board/common/overlay/etc/init.d/S14postupgrade
@@ -5,8 +5,6 @@ test -n "$os_version" || source /etc/init.d/base
 sys_version_file="/etc/version"
 version_file="/data/etc/version"
 post_upgrade_dir="/usr/share/post-upgrade"
-sys_os_conf="/etc/os.conf"
-os_conf="/data/etc/os.conf"
 
 hash=$(md5sum $version_file 2>/dev/null | cut -d ' ' -f 1)
 sys_hash=$(md5sum $sys_version_file 2>/dev/null | cut -d ' ' -f 1)
@@ -38,23 +36,10 @@ function run_post_upgrade() {
     done
 }
 
-function update_os_conf() {
-    source $sys_os_conf
-    sys_vars=$(cat $sys_os_conf | cut -d '=' -f 1)
-    for var in $sys_vars; do
-        if ! grep "$var=" $os_conf &>/dev/null; then
-            msg_begin "Adding $var to os.conf"
-            echo "$var=\"${!var}\"" >> $os_conf
-            msg_done
-        fi
-    done
-}
-
 case "$1" in
     start)
         run_post_upgrade
         cp $sys_version_file $version_file
-        update_os_conf
         ;;
 
     stop)
diff --git a/board/common/overlay/etc/init.d/S35wifi b/board/common/overlay/etc/init.d/S35wifi
index 60ec787932..018ee5852e 100755
--- a/board/common/overlay/etc/init.d/S35wifi
+++ b/board/common/overlay/etc/init.d/S35wifi
@@ -12,36 +12,12 @@ sys_watch_conf="/etc/watch.conf"
 boot_watch_conf="/boot/watch.conf"
 watch_conf="/data/etc/watch.conf"
 
-if ! [[ -f $watch_conf ]]; then
-    if [[ -f $boot_watch_conf ]]; then
-        cp $boot_watch_conf $watch_conf
-    elif [[ -f $sys_watch_conf ]]; then
-        cp $sys_watch_conf $watch_conf
-    fi
-fi
-
+prepare_conf $watch_conf $sys_watch_conf $boot_watch_conf
 source $watch_conf
 
-if [[ -f $boot_conf ]]; then
-    cp -f $boot_conf $conf
-    grep -E "/boot .*ro[\s,]" /proc/mounts
-    RO=$?
-    test $RO == 0 && mount -o remount,rw /boot
-    rm -f $boot_conf
-    test $RO == 0 && mount -o remount,ro /boot
-fi
-
-if ! [[ -f $conf ]]; then
-    if [[ -f $sys_conf ]]; then
-        cp $sys_conf $conf
-    fi
-fi
-
+prepare_conf $conf $sys_conf $boot_conf
 test -f $conf || exit 0
 
-# we want only Unix newlines here
-sed -i 's/\r//g' $conf
-
 ssid=$(cat $conf | grep ssid | grep -v scan_ssid | cut -d '"' -f 2)
 test -n "$ssid" || exit 0
 
diff --git a/board/common/overlay/etc/init.d/conf b/board/common/overlay/etc/init.d/conf
index 46ab1a6378..c8fd635052 100644
--- a/board/common/overlay/etc/init.d/conf
+++ b/board/common/overlay/etc/init.d/conf
@@ -2,28 +2,20 @@
 
 _sys_conf="/etc/os.conf"
 _boot_conf="/boot/os.conf"
-_conf="/data/etc/os.conf"
+_data_conf="/data/etc/os.conf"
 
-if ! [[ -d /data/etc ]]; then
-    # use boot/system variants if we don't have the data partition mounted
-    if [[ -f $_boot_conf ]]; then
-        source $_boot_conf
-    elif [[ -f $_sys_conf ]]; then
-        source $_sys_conf
-    fi
-
-    return
+# source in all conf files in order of precedence
+if [[ -f $_sys_conf ]]; then
+    source $_sys_conf
 fi
 
-if ! [[ -f $_conf ]]; then
-    if [[ -f $_boot_conf ]]; then
-        cp $_boot_conf $_conf
-    elif [[ -f $_sys_conf ]]; then
-        cp $_sys_conf $_conf
-    fi
+if [[ -f $_data_conf ]]; then
+    source $_data_conf
 fi
 
-if [[ -f $_conf ]]; then
-    source $_conf
+if [[ -f $_boot_conf ]]; then
+    source $_boot_conf
 fi
 
+unset _sys_conf _boot_conf _data_conf
+
diff --git a/board/common/overlay/sbin/fwupdate b/board/common/overlay/sbin/fwupdate
index ea3bfeb0f6..fd7bee5db1 100755
--- a/board/common/overlay/sbin/fwupdate
+++ b/board/common/overlay/sbin/fwupdate
@@ -35,7 +35,6 @@ fi
 
 SYS_VERSION_FILE=/etc/version
 SYS_BOARD_FILE=/etc/board
-OS_CONF=/data/etc/os.conf
 
 MIN_FREE_DISK=$((500*1024))  # 500 MB
 VER_FILE=version
@@ -78,7 +77,8 @@ fi
 #### versions ####
 
 function show_versions() {
-    source $OS_CONF
+    source /etc/init.d/conf  # we need this for the os_ vars
+    
     board=$(cat $SYS_BOARD_FILE)
     show_json=$1
   
@@ -144,7 +144,8 @@ function do_download() {
         fi
     fi
 
-    source $OS_CONF
+    source /etc/init.d/conf  # we need this for the os_ vars
+    
     board=$(cat $SYS_BOARD_FILE)
     url=$1
     version=$1