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Diffstat (limited to '')
| -rw-r--r-- | include/export/README | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/include/export/README b/include/export/README new file mode 100644 index 0000000..2de8d6b --- /dev/null +++ b/include/export/README @@ -0,0 +1,33 @@ +All headers under include/export/ are export headers that are intended for +inclusion in third-party code which needs to interact with TF-A data structures +or interfaces. They must follow these special rules: + +- Header guards should start with ARM_TRUSTED_FIRMWARE_ to reduce clash risk. + +- All definitions should be sufficiently namespaced (e.g. with BL_ or TF_) to + make name clashes with third-party code unlikely. + +- They must not #include any headers except other export headers, and those + includes must use relative paths with "../double_quotes.h" notation. + +- They must not rely on any type definitions other that <stdint.h> types defined + in the ISO C standard (i.e. uint64_t is fine, but not u_register_t). They + should still not #include <stdint.h>. Instead, wrapper headers including + export headers need to ensure that they #include <stdint.h> earlier in their + include order. + +- They must not rely on any macro definitions other than those which are + pre-defined by all common compilers (e.g. __ASSEMBLER__ or __aarch64__). + +- They must only contain macro, type and structure definitions, no prototypes. + +- They should avoid using integer types with architecture-dependent widths + (e.g. long, uintptr_t, pointer types) where possible. (Some existing export + headers are violating this for now.) + +- Their names should always end in "_exp.h". + +- Normal TF-A code should never include export headers directly. Instead, it + should include a wrapper header that ensures the export header is included in + the right manner. (The wrapper header for include/export/x/y/z_exp.h should + normally be placed at include/x/y/z.h.) |