forked from Mirrors/opensbi
86c01a73ff
OpenSBI is compiled with -fPIE, which generally implies dynamic linking. This causes the compiler to generate GOT references for global symbols in order to support runtime symbol interposition. However, OpenSBI does not actually perform dynamic linking, so the GOT indirection just adds unnecessary overhead. The GOT references can be avoided by declaring global symbols with hidden visibility, thus making them local to this dynamic object and non-interposable. GCC/Clang's -fvisibility parameter is insufficient for this purpose when referencing objects from other translation units; either __attribute__((visibility(...)) or the pragma is required. Use the pragma since it is easier to apply to every symbol. Additionally clean up the one GOT reference from inline assembly. With this change, a firmware linked with LLD does not contain either a GOT or a PLT, and a firmware linked with BFD ld contains only a GOT with a single (unreferenced, legacy) _GLOBAL_OFFSET_TABLE_ entry. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org>