Try to generate the same initrd every time, so we only need to provision
the verifier once.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

Create a macvtap interface on boot, ready to be used by a VMM. In
particular cloud-hypervisor doesn't do user networking and always
requires a tap interface.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

Modify a couple of /etc/ files in the buildroot images to help boot and
attest a realm.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

See buildroot/docs/manual/customize-outside-br.adoc

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>