ARM ARMv8-M Security Extensions (Using the GNU Compiler Collection (GCC))

#### 7.13.7 ARM ARMv8-M Security Extensions ¶

GCC implements the ARMv8-M Security Extensions as described in the ARMv8-M Security Extensions: Requirements on Development Tools Engineering Specification, which can be found at https://developer.arm.com/documentation/ecm0359818/latest/.

As part of the Security Extensions GCC implements two new function attributes: `cmse_nonsecure_entry` and `cmse_nonsecure_call`.

As part of the Security Extensions GCC implements the intrinsics below. FPTR is used here to mean any function pointer type.

    cmse_address_info_t cmse_TT (void *);
    cmse_address_info_t cmse_TT_fptr (FPTR);
    cmse_address_info_t cmse_TTT (void *);
    cmse_address_info_t cmse_TTT_fptr (FPTR);
    cmse_address_info_t cmse_TTA (void *);
    cmse_address_info_t cmse_TTA_fptr (FPTR);
    cmse_address_info_t cmse_TTAT (void *);
    cmse_address_info_t cmse_TTAT_fptr (FPTR);
    void * cmse_check_address_range (void *, size_t, int);
    typeof(p) cmse_nsfptr_create (FPTR p);
    intptr_t cmse_is_nsfptr (FPTR);
    int cmse_nonsecure_caller (void);