fix SDcard build
Merge branch 'dx4-v7' of https://github.com/jvonau/dx4-oob-v7.0 into dx4-v7
Merge branch 'dx4-v7' of https://github.com/jvonau/dx4-oob-v7.0 into dx4-v7
Merge branch 'dx4-v7' of https://github.com/jvonau/dx4-oob-v7.0 into dx4-v7