Hi, The isolation level 2 patches are pushed for reviewing; you can find all of them under the issue: https://developer.trustedfirmware.org/T294
The design document was put at: https://developer.trustedfirmware.org/w/tf_m/design/trusted_firmware-m_isola...
The first group of patches are working on AN521 with ARMCLANG build. Rest options supporting would come later.
With higher isolation level, some functions may not work such as CLIB (malloc/free e.g.). These features need to be supported after dedicated implementation is done. You can check the [RFC] discussion sent in mailing list of the isolation level 2 for details. Isolation level 2 use dedicated config file: "ConfigCoreIPCTfmLevel2.cmake" so the IPC on isolation level 1 is not affected by this change.
Please help to comment in documents and patches - current the document has no comment area so you can put comments under the issue link, or just reply in mailing list. Creating issues is another valid options ; )
Thanks!
-Ken