1*91f16700SchasingluluAll headers under include/export/ are export headers that are intended for 2*91f16700Schasingluluinclusion in third-party code which needs to interact with TF-A data structures 3*91f16700Schasingluluor interfaces. They must follow these special rules: 4*91f16700Schasinglulu 5*91f16700Schasinglulu- Header guards should start with ARM_TRUSTED_FIRMWARE_ to reduce clash risk. 6*91f16700Schasinglulu 7*91f16700Schasinglulu- All definitions should be sufficiently namespaced (e.g. with BL_ or TF_) to 8*91f16700Schasinglulu make name clashes with third-party code unlikely. 9*91f16700Schasinglulu 10*91f16700Schasinglulu- They must not #include any headers except other export headers, and those 11*91f16700Schasinglulu includes must use relative paths with "../double_quotes.h" notation. 12*91f16700Schasinglulu 13*91f16700Schasinglulu- They must not rely on any type definitions other that <stdint.h> types defined 14*91f16700Schasinglulu in the ISO C standard (i.e. uint64_t is fine, but not u_register_t). They 15*91f16700Schasinglulu should still not #include <stdint.h>. Instead, wrapper headers including 16*91f16700Schasinglulu export headers need to ensure that they #include <stdint.h> earlier in their 17*91f16700Schasinglulu include order. 18*91f16700Schasinglulu 19*91f16700Schasinglulu- They must not rely on any macro definitions other than those which are 20*91f16700Schasinglulu pre-defined by all common compilers (e.g. __ASSEMBLER__ or __aarch64__). 21*91f16700Schasinglulu 22*91f16700Schasinglulu- They must only contain macro, type and structure definitions, no prototypes. 23*91f16700Schasinglulu 24*91f16700Schasinglulu- They should avoid using integer types with architecture-dependent widths 25*91f16700Schasinglulu (e.g. long, uintptr_t, pointer types) where possible. (Some existing export 26*91f16700Schasinglulu headers are violating this for now.) 27*91f16700Schasinglulu 28*91f16700Schasinglulu- Their names should always end in "_exp.h". 29*91f16700Schasinglulu 30*91f16700Schasinglulu- Normal TF-A code should never include export headers directly. Instead, it 31*91f16700Schasinglulu should include a wrapper header that ensures the export header is included in 32*91f16700Schasinglulu the right manner. (The wrapper header for include/export/x/y/z_exp.h should 33*91f16700Schasinglulu normally be placed at include/x/y/z.h.) 34