Hi Bryan,
On Fri, Mar 9, 2018 at 10:07 AM, Bryan O'Donoghue bryan.odonoghue@linaro.org wrote:
commit 8c4037a09a5c ("imx: hab: Ensure the IVT DCD pointer is Null prior to calling HAB authenticate function.") makes the DCD field being NULL a dependency.
This change though will break loading and executing of existing pre-signed binaries on a u-boot update i.e. if this change is deployed on a board you will be forced to redo all images on that board to NULL out the DCD.
There is no prior guidance from NXP that the DCD must be NULL similarly public guidance on usage of the HAB doesn't call out this NULL dependency (see boundary devices link).
Since later SoCs will reject a non-NULL DCD there's no reason to make a NULL DCD a requirement, however if there is an actual dependency for later SoCs the appropriate fix would be to do SoC version checking.
Earlier SoCs are capable (and happy) to authenticate images with non-NULL DCDs, we should not be forcing this change on downstream users - particularly if it means those users now must rewrite their build systems and/or redeploy signed images in the field.
Fixes: 8c4037a09a5c ("imx: hab: Ensure the IVT DCD pointer is Null prior to calling HAB authenticate function.")
Signed-off-by: Bryan O'Donoghue bryan.odonoghue@linaro.org Cc: Utkarsh Gupta utkarsh.gupta@nxp.com Cc: Breno Lima breno.lima@nxp.com Cc: Fabio Estevam fabio.estevam@nxp.com Link: https://boundarydevices.com/high-assurance-boot-hab-dummies
Utkarsh is currently out of the office, but Breno knows the details about 8c4037a09a5c ("imx: hab: Ensure the IVT DCD pointer is Null prior to calling HAB authenticate function.") and will comment.
Thanks