Bug#992304: possible workaround
Try using the kernel parameter: intel_iommu=off
Bug#954888: Dependency for linux-image-arm64 on stretch-backports not available
This was fixed, but now is broken again since the dependency changed: https://packages.debian.org/stretch-backports/linux-image-arm64 dep: linux-image-4.19.0-0.bpo.9-arm64 Package not available