Revert the feature: serial port watchdog service (#1766)

* Revert "[serial watchdog] remove serial watchdog service dependency to rc.local (#1752)"
* Revert "[service] introducing serial port watchdog service (#1743)"

files/build_templates/sonic_debian_extension.j2

@@ -154,11 +154,6 @@ sudo cp $IMAGE_CONFIGS/hostname/hostname-config.service  $FILESYSTEM_ROOT/etc/sy
 sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable hostname-config.service
 sudo cp $IMAGE_CONFIGS/hostname/hostname-config.sh $FILESYSTEM_ROOT/usr/bin/
 
-# Copy serial-port-watchdog configuration scripts
-sudo cp $IMAGE_CONFIGS/serial-port-watchdog/serial-port-watchdog.service  $FILESYSTEM_ROOT/etc/systemd/system/
-sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable serial-port-watchdog.service
-sudo cp $IMAGE_CONFIGS/serial-port-watchdog/serial-port-watchdog.py $FILESYSTEM_ROOT/usr/bin/
-
 # Copy updategraph script and service file
 sudo cp $IMAGE_CONFIGS/updategraph/updategraph.service  $FILESYSTEM_ROOT/etc/systemd/system/
 sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable updategraph.service

files/image_config/platform/rc.local

@@ -183,51 +183,15 @@ for x in "$@"; do
 done
 }
 
-setup_platform()
-{
+eval sonic_version=$(cat /etc/sonic/sonic_version.yml | grep build_version | cut -f2 -d" ")
+
+if [ -f /host/image-$sonic_version/platform/firsttime ]; then
+
     if [ -n "$aboot_platform" ]; then
         platform=$aboot_platform
     elif [ -n "$onie_platform" ]; then
         platform=$onie_platform
     else
-        platform=''
-    fi
-}
-
-# Setup default values in this function before reading installer.conf
-# installer.conf could override the value set in this function.
-setup_platform_defaults()
-{
-    # Default serial port: ttyS0
-    CONSOLE_DEV=0
-}
-
-load_platform_installer_config()
-{
-    INSTALLER_CFG=/usr/share/sonic/device/$platform/installer.conf
-    if [ -f $INSTALLER_CFG ]; then
-        . $INSTALLER_CFG
-    fi
-}
-
-program_serial_port()
-{
-    sed -i "s|ttyS.|ttyS$CONSOLE_DEV|g" /etc/systemd/system/serial-port-watchdog.service
-    systemctl daemon-reload
-    systemctl restart serial-port-watchdog.service
-}
-
-eval sonic_version=$(cat /etc/sonic/sonic_version.yml | grep build_version | cut -f2 -d" ")
-
-setup_platform
-setup_platform_defaults
-load_platform_installer_config
-
-program_serial_port
-
-if [ -f /host/image-$sonic_version/platform/firsttime ]; then
-
-    if [ -z "$platform" ]; then
         echo "Unknown sonic platform"
         firsttime_exit
     fi