raspbiantools - downgrade package instead for stretch bt fix

 * there are additional issues with the newer kernel including overscan problems
 * add option to pass parameter to apt-mark to hold/unhold and hold downgraded packages

scriptmodules/supplementary/raspbiantools.sh

@@ -43,24 +43,29 @@ function disable_blanker_raspbiantools() {
 }
 
 function kernel_bt_fix_raspbiantools() {
-    # install a newer kernel/firmware for stretch to resolve sony bt issues
-    if isPlatform "rpi" && [[ "$__os_debian_ver" -eq 9 ]] && hasPackage raspberrypi-kernel 1.20190620+1-1 lt; then
-        install_firmware_raspbiantools 1.20190620+1-1
+    local ver="1.20190401-1"
+    # install an older kernel/firmware for stretch to resolve sony bt and overscan issues
+    if isPlatform "rpi" && [[ "$__os_debian_ver" -eq 9 ]] && hasPackage raspberrypi-kernel "$ver" ne; then
+        install_firmware_raspbiantools "$ver" hold
     fi
 }
 
 function install_firmware_raspbiantools() {
     local ver="$1"
+    local state="$2"
     [[ -z "$ver" ]] && return 1
     local url="http://archive.raspberrypi.org/debian/pool/main/r/raspberrypi-firmware"
     mkdir -p "$md_build"
     pushd "$md_build" >/dev/null
     local pkg
+    local deb
     for pkg in raspberrypi-bootloader libraspberrypi0 libraspberrypi-doc libraspberrypi-dev libraspberrypi-bin raspberrypi-kernel-headers raspberrypi-kernel; do
-        wget -O"${pkg}_${ver}_armhf.deb" "$url/${pkg}_${ver}_armhf.deb"
+        deb="${pkg}_${ver}_armhf.deb"
+        wget -O"$deb" "$url/$deb"
+        dpkg -i "$deb"
+        [[ -n "$state" ]] && apt-mark "$state" "$pkg"
+        rm "$deb"
     done
-    dpkg -i *.deb
-    rm *.deb
     popd >/dev/null
     rm -rf "$md_build"
 }