From c1094987d1dc4701646c5f3aa254e7a92a02d305 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Thu, 20 May 2021 13:24:03 +0200 Subject: build: support building with Link Time Optimizations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add plumbing for building U-Boot with Link Time Optimizations. When building with LTO, $(PLATFORM_LIBS) has to be in --whole-archive / --no-whole-archive group, otherwise some functions declared in assembly may not be resolved and linking may fail. Note: clang may throw away linker list symbols it thinks are unused when compiling with LTO. To force these symbols to be included, we refer to them via the __ADDRESSABLE macro in a C file generated from compiled built-in.o files before linking. Signed-off-by: Marek Behún Reviewed-by: Simon Glass --- scripts/Makefile.lib | 3 +++ 1 file changed, 3 insertions(+) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 78543c6dd1..78bbebe7e9 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -419,6 +419,9 @@ $(obj)/%_efi.so: $(obj)/%.o $(obj)/efi_crt0.o $(obj)/efi_reloc.o $(obj)/efi_free targets += $(obj)/efi_crt0.o $(obj)/efi_reloc.o $(obj)/efi_freestanding.o +CFLAGS_REMOVE_efi_reloc.o := $(LTO_CFLAGS) +CFLAGS_REMOVE_efi_freestanding.o := $(LTO_CFLAGS) + # ACPI # --------------------------------------------------------------------------- # -- cgit