1. Enable IAR on non-secure targets
2. Disable IAR on secure targets because:
(1) IAR toolchain bug: As of IAR 8.32, cmse_nonsecure_caller() is not always inlined.
(2) TFM hasn't supported IAR yet.
On M2351, some spaces like SYS/CLK are hard-wired to secure and cannot change.
To access these spaces from non-secure world, we must provide platform-specific NSC
functions. With TFM introduced, we must synchronize NSC calls into TFM to keep TFM
in sync instead of straight NSC calls. To achieve this goal, we go with the following
approach:
1. Like PSA APIs, enforce locked entry through tfm_ns_lock_dispatch().
2. Run platform-specific secure functions in default secure partition, in which SYS/CLK
spaces have been configured to be accessible.
1. Rename m2351_stddriver_sup.h/c to stddriver_secure.h/.c for naming consistency
2. Add hal_secure.h to include hal-exported secure functions
3. Change return/argument type in secure functions:
(1) Change int to int32_t
(2) Change PinName to int32_t
(3) Change time_t to int64_t
4. Update secure lib/bin accordingly
1. Power down RTC access from CPU domain in rtc_free. After rtc_free, RTC gets
inaccessible from CPU domain but keeps counting.
2. Fix RTC cannot cross reset cycle.
Chun-Chieh Li
cyliangtw