Hi,
Partition is described through configuration in YAML files (manifests). This configuration includes following properties (see Adding Secure Partition - Add manifesthttps://tf-m-user-guide.trustedfirmware.org/integration_guide/services/tfm_secure_partition_addition.html?highlight=named%20mmio#add-manifest):
* Name, type, priority, model, ... * List of services provided by partition * MMIO regions * List of IRQs * Dependencies
Each platform should provide implementation of HAL which is specific to standard partitions like Crypto, ITS, etc. It's mandatory to provide proper isolation of memory/peripheral that are used by platform specific code that provides HAL implementation or add a custom dependency for standard partition.
Currently platform can use following approaches to resolve the problem of extending YAML of standard TF-M partition:
* Create a platform specific copy of partition YAML, see https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/15639 as an example of such approach. * Modify standard partition by introducing optional fields, see https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/17718. These both solution are not flexible enough. It requires to modify platform independent code or maintain own copy of partition YAML file with needed changes.
I think it make sense to integrate partition YAML extension tool in TF-M. Platform/application should be able to provide manifest-extension file(s). Such manifest-extension file may provide additional properties which should be joined with properties provided by standard partition manifest files.
For example to solve problem for https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/15639 ARM RSS platform may provide following manifest-extension file with structure like this: { "extensions": [ { "name": "TFM_SP_INITIAL_ATTESTATION", "dependencies": [ "TFM_MEASURED_BOOT" ] } ] }
Tool which parses manifests should add a new dependency on "TFM_MEASURED_BOOT" to list of dependencies for "TFM_SP_INITIAL_ATTESTATION" partition.
Please, share your opinion on this topic.
Best regards, Roman.