diff options
| author | Simon Glass | 2022-08-03 12:13:08 -0600 |
|---|---|---|
| committer | Tom Rini | 2022-09-02 16:20:11 -0400 |
| commit | a55014d09b29d7bc2cbaeb8e41a155c9a257a183 (patch) | |
| tree | 7651a422b0d01a6a8ed0375e8f1a6eff3065df3f /arch/arm | |
| parent | 583f1b2f10be36f86a2da3686d406bfd90cfbc70 (diff) | |
Makefile: Allow LTO to be disabled for a build
LTO (Link-Time Optimisation) is an very useful feature which can
significantly reduce the size of U-Boot binaries. So far it has been
made available for selected ARM boards and sandbox.
However, incremental builds are much slower when LTO is used. For example,
an incremental build of sandbox takes 2.1 seconds on my machine, but 6.7
seconds with LTO enabled.
Add a NO_LTO parameter to the build, similar to NO_SDL, so it can be
disabled during development if needed, for faster builds.
Add some documentation about LTO while we are here.
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/config.mk | 4 | ||||
| -rw-r--r-- | arch/arm/include/asm/global_data.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm/config.mk b/arch/arm/config.mk index b3548ce2439..2065438d053 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -15,11 +15,11 @@ CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections \ -fstack-protector-strong CFLAGS_EFI := -fpic -fshort-wchar -ifneq ($(CONFIG_LTO)$(CONFIG_USE_PRIVATE_LIBGCC),yy) +ifneq ($(LTO_ENABLE)$(CONFIG_USE_PRIVATE_LIBGCC),yy) LDFLAGS_FINAL += --gc-sections endif -ifndef CONFIG_LTO +ifneq ($(LTO_ENABLE),y) PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections endif diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h index 6ee2a767615..cd6112dfcda 100644 --- a/arch/arm/include/asm/global_data.h +++ b/arch/arm/include/asm/global_data.h @@ -101,7 +101,7 @@ struct arch_global_data { #include <asm-generic/global_data.h> -#if defined(__clang__) || defined(CONFIG_LTO) +#if defined(__clang__) || defined(LTO_ENABLE) #define DECLARE_GLOBAL_DATA_PTR #define gd get_gd() |