Merge branch '2021-05-24-add-lto-support'

- Add LTO (link time optimization) support to the build system and enable it on a few boards. This is an alternative to using -ffunction-sections/-fdata-sections and --gc-sections at link time to remove unused code. This can result in notable savings, but needs testing on each platform before use as it can expose problems by optimizing away various functionally necessary calls.
2024-11-25 06:00:43 +00:00 · 2021-05-24 16:12:31 -04:00 · 2021-05-24 16:12:31 -04:00 · 27c6d9663c
commit 27c6d9663c
parent eb53b943be 2fc62f2991
110 changed files with 523 additions and 187 deletions
--- a/2
+++ b/2
@ -10,6 +10,8 @@ generic-offsets-file := include/generated/generic-asm-offsets.h
 always  := $(generic-offsets-file)
 targets := lib/asm-offsets.s

+CFLAGS_REMOVE_asm-offsets.o := $(LTO_CFLAGS)
+
 $(obj)/$(generic-offsets-file): $(obj)/lib/asm-offsets.s FORCE
 	$(call filechk,offsets,__GENERIC_ASM_OFFSETS_H__)

--- a/24
+++ b/24
@ -85,6 +85,30 @@ config SPL_OPTIMIZE_INLINING
 	  do what it thinks is best, which is desirable in some cases for size
 	  reasons.

+config ARCH_SUPPORTS_LTO
+	bool
+
+config LTO
+	bool "Enable Link Time Optimizations"
+	depends on ARCH_SUPPORTS_LTO
+	default n
+	help
+	  This option enables Link Time Optimization (LTO), a mechanism which
+	  allows the compiler to optimize between different compilation units.
+
+	  This can optimize away dead code paths, resulting in smaller binary
+	  size (if CC_OPTIMIZE_FOR_SIZE is enabled).
+
+	  This option is not available for every architecture and may
+	  introduce bugs.
+
+	  Currently, when compiling with GCC, due to a weird bug regarding
+	  jobserver, the final linking will not respect make's --jobs argument.
+	  Instead all available processors will be used (as reported by the
+	  nproc command).
+
+	  If unsure, say n.
+
 config TPL_OPTIMIZE_INLINING
 	bool "Allow compiler to uninline functions marked 'inline' in TPL"
 	depends on TPL
--- a/81
+++ b/81
@ -676,6 +676,31 @@ else
 KBUILD_CFLAGS	+= -O2
 endif

+LTO_CFLAGS :=
+LTO_FINAL_LDFLAGS :=
+export LTO_CFLAGS LTO_FINAL_LDFLAGS
+ifdef CONFIG_LTO
+	ifeq ($(cc-name),clang)
+		LTO_CFLAGS		+= -flto
+		LTO_FINAL_LDFLAGS	+= -flto
+
+		AR			= $(shell $(CC) -print-prog-name=llvm-ar)
+		NM			= $(shell $(CC) -print-prog-name=llvm-nm)
+	else
+		NPROC			:= $(shell nproc 2>/dev/null || echo 1)
+		LTO_CFLAGS		+= -flto=$(NPROC)
+		LTO_FINAL_LDFLAGS	+= -fuse-linker-plugin -flto=$(NPROC)
+
+		# use plugin aware tools
+		AR			= $(CROSS_COMPILE)gcc-ar
+		NM			= $(CROSS_COMPILE)gcc-nm
+	endif
+
+	CFLAGS_NON_EFI			+= $(LTO_CFLAGS)
+
+	KBUILD_CFLAGS			+= $(LTO_CFLAGS)
+endif
+
 ifeq ($(CONFIG_STACKPROTECTOR),y)
 KBUILD_CFLAGS += $(call cc-option,-fstack-protector-strong)
 CFLAGS_EFI += $(call cc-option,-fno-stack-protector)
@ -972,6 +997,8 @@ LDFLAGS_u-boot += $(LDFLAGS_FINAL)
 # Avoid 'Not enough room for program headers' error on binutils 2.28 onwards.
 LDFLAGS_u-boot += $(call ld-option, --no-dynamic-linker)

+LDFLAGS_u-boot += --build-id=none
+
 ifeq ($(CONFIG_ARC)$(CONFIG_NIOS2)$(CONFIG_X86)$(CONFIG_XTENSA),)
 LDFLAGS_u-boot += -Ttext $(CONFIG_SYS_TEXT_BASE)
 endif
@ -1708,14 +1735,54 @@ u-boot-swap.bin: u-boot.bin FORCE

 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(ARCH)/Makefile.postlink)

+# Generate linker list symbols references to force compiler to not optimize
+# them away when compiling with LTO
+ifdef CONFIG_LTO
+u-boot-keep-syms-lto := keep-syms-lto.o
+u-boot-keep-syms-lto_c := $(patsubst %.o,%.c,$(u-boot-keep-syms-lto))
+
+quiet_cmd_keep_syms_lto = KSL     $@
+      cmd_keep_syms_lto = \
+	NM=$(NM) $(srctree)/scripts/gen_ll_addressable_symbols.sh $^ >$@
+
+quiet_cmd_keep_syms_lto_cc = KSLCC   $@
+      cmd_keep_syms_lto_cc = \
+	$(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o $@ $<
+
+$(u-boot-keep-syms-lto_c): $(u-boot-main)
+	$(call if_changed,keep_syms_lto)
+$(u-boot-keep-syms-lto): $(u-boot-keep-syms-lto_c)
+	$(call if_changed,keep_syms_lto_cc)
+else
+u-boot-keep-syms-lto :=
+endif
+
 # Rule to link u-boot
 # May be overridden by arch/$(ARCH)/config.mk
+ifdef CONFIG_LTO
+quiet_cmd_u-boot__ ?= LTO     $@
+      cmd_u-boot__ ?= 								\
+		$(CC) -nostdlib -nostartfiles					\
+		$(LTO_FINAL_LDFLAGS) $(c_flags)					\
+		$(KBUILD_LDFLAGS:%=-Wl,%) $(LDFLAGS_u-boot:%=-Wl,%) -o $@	\
+		-T u-boot.lds $(u-boot-init)					\
+		-Wl,--whole-archive						\
+			$(u-boot-main)						\
+			$(u-boot-keep-syms-lto)					\
+			$(PLATFORM_LIBS)					\
+		-Wl,--no-whole-archive						\
+		-Wl,-Map,u-boot.map;						\
+		$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
+else
 quiet_cmd_u-boot__ ?= LD      $@
-      cmd_u-boot__ ?= $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_u-boot) -o $@ \
-      -T u-boot.lds $(u-boot-init)                             \
-      --start-group $(u-boot-main) --end-group                 \
-      $(PLATFORM_LIBS) -Map u-boot.map;                        \
-      $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
+      cmd_u-boot__ ?= $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_u-boot) -o $@		\
+		-T u-boot.lds $(u-boot-init)					\
+		--whole-archive							\
+			$(u-boot-main)						\
+		--no-whole-archive						\
+		$(PLATFORM_LIBS) -Map u-boot.map;				\
+		$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
+endif

 quiet_cmd_smap = GEN     common/system_map.o
 cmd_smap = \
@ -1724,7 +1791,7 @@ cmd_smap = \
 	$(CC) $(c_flags) -DSYSTEM_MAP="\"$${smap}\"" \
 		-c $(srctree)/common/system_map.c -o common/system_map.o

-u-boot:	$(u-boot-init) $(u-boot-main) u-boot.lds FORCE
+u-boot:	$(u-boot-init) $(u-boot-main) $(u-boot-keep-syms-lto) u-boot.lds FORCE
 	+$(call if_changed,u-boot__)
 ifeq ($(CONFIG_KALLSYMS),y)
 	$(call cmd,smap)
@ -2007,7 +2074,7 @@ CLEAN_FILES += include/bmp_logo.h include/bmp_logo_data.h tools/version.h \
 	       boot* u-boot* MLO* SPL System.map fit-dtb.blob* \
 	       u-boot-ivt.img.log u-boot-dtb.imx.log SPL.log u-boot.imx.log \
 	       lpc32xx-* bl31.c bl31.elf bl31_*.bin image.map tispl.bin* \
-	       idbloader.img flash.bin flash.log defconfig
+	       idbloader.img flash.bin flash.log defconfig keep-syms-lto.c

 # Directories & files removed with 'make mrproper'
 MRPROPER_DIRS  += include/config include/generated spl tpl \
--- a/arch/Kconfig
+++ b/arch/Kconfig
@ -33,6 +33,7 @@ config ARC

 config ARM
 	bool "ARM architecture"
+	select ARCH_SUPPORTS_LTO
 	select CREATE_ARCH_SYMLINK
 	select HAVE_PRIVATE_LIBGCC if !ARM64
 	select SUPPORT_OF_CONTROL
@ -101,6 +102,7 @@ config RISCV

 config SANDBOX
 	bool "Sandbox"
+	select ARCH_SUPPORTS_LTO
 	select BOARD_LATE_INIT
 	select BZIP2
 	select CMD_POWEROFF
@ -124,6 +126,7 @@ config SANDBOX
 	select SUPPORT_EXTENSION_SCAN
 	imply BITREVERSE
 	select BLOBLIST
+	imply LTO
 	imply CMD_DM
 	imply CMD_EXCEPTION
 	imply CMD_GETTIME
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@ -15,9 +15,15 @@ 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)
 LDFLAGS_FINAL += --gc-sections
-PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections \
-		     -fno-common -ffixed-r9
+endif
+
+ifndef CONFIG_LTO
+PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections
+endif
+
+PLATFORM_RELFLAGS += -fno-common -ffixed-r9
 PLATFORM_RELFLAGS += $(call cc-option, -msoft-float) \
      $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))

--- a/arch/arm/cpu/arm926ejs/Makefile
+++ b/arch/arm/cpu/arm926ejs/Makefile
@ -25,6 +25,8 @@ ifndef CONFIG_HAS_THUMB2

 CFLAGS_cpu.o := -marm
 CFLAGS_cache.o := -marm
+CFLAGS_REMOVE_cpu.o := $(LTO_CFLAGS)
+CFLAGS_REMOVE_cache.o := $(LTO_CFLAGS)

 endif
 endif
--- a/arch/arm/cpu/arm926ejs/mxs/mxs.c
+++ b/arch/arm/cpu/arm926ejs/mxs/mxs.c
@ -25,6 +25,7 @@
 #include <asm/arch/iomux.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/sys_proto.h>
+#include <asm/sections.h>
 #include <linux/compiler.h>

 DECLARE_GLOBAL_DATA_PTR;
@ -98,7 +99,6 @@ int arch_cpu_init(void)
 {
 	struct mxs_clkctrl_regs *clkctrl_regs =
 		(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
-	extern uint32_t _start;

 	mx28_fixup_vt((uint32_t)&_start);

--- a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
@ -16,6 +16,7 @@
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/gpio.h>
+#include <asm/sections.h>
 #include <linux/compiler.h>

 #include "mxs_init.h"
@ -100,7 +101,6 @@ static void mxs_spl_fixup_vectors(void)
 	 * thus this fixup. Our vectoring table is PIC, so copying is
 	 * fine.
 	 */
-	extern uint32_t _start;

 	/* cppcheck-suppress nullPointer */
 	memcpy(0x0, &_start, 0x60);
@ -122,7 +122,7 @@ void mxs_common_spl_init(const uint32_t arg, const uint32_t *resptr,
 {
 	struct mxs_spl_data *data = MXS_SPL_DATA;
 	uint8_t bootmode = mxs_get_bootmode_index();
-	gd = &gdata;
+	set_gd(&gdata);

 	mxs_spl_fixup_vectors();

--- a/arch/arm/cpu/arm926ejs/spear/spl.c
+++ b/arch/arm/cpu/arm926ejs/spear/spl.c
@ -22,7 +22,7 @@
 * The BSS cannot be used for this purpose because it will be zeroed after
 * having stored the pointer, so force the location to the data section.
 */
-u32 bootrom_stash_sp __attribute__((section(".data")));
+u32 bootrom_stash_sp __section(".data");

 static void ddr_clock_init(void)
 {
--- a/arch/arm/cpu/armv7/kona-common/clk-stubs.c
+++ b/arch/arm/cpu/armv7/kona-common/clk-stubs.c
@ -14,7 +14,7 @@ int __weak clk_sdio_enable(void *base, u32 rate, u32 *actual_ratep)
 	return 0;
 }

-int __weak clk_bsc_enable(void *base, u32 rate, u32 *actual_ratep)
+int __weak clk_bsc_enable(void *base)
 {
 	return 0;
 }
--- a/arch/arm/cpu/armv7/ls102xa/ls102xa_psci.c
+++ b/arch/arm/cpu/armv7/ls102xa/ls102xa_psci.c
@ -13,7 +13,7 @@
 #include <fsl_immap.h>
 #include "fsl_epu.h"

-#define __secure __attribute__((section("._secure.text")))
+#define __secure __section("._secure.text")

 #define CCSR_GICD_CTLR			0x1000
 #define CCSR_GICC_CTLR			0x2000
--- a/arch/arm/cpu/armv8/spl_data.c
+++ b/arch/arm/cpu/armv8/spl_data.c
@ -6,8 +6,8 @@
 #include <common.h>
 #include <spl.h>

-char __data_save_start[0] __section(.__data_save_start);
-char __data_save_end[0] __section(.__data_save_end);
+char __data_save_start[0] __section(".__data_save_start");
+char __data_save_end[0] __section(".__data_save_end");

 u32 cold_reboot_flag = 1;

--- a/arch/arm/cpu/armv8/u-boot-spl.lds
+++ b/arch/arm/cpu/armv8/u-boot-spl.lds
@ -77,6 +77,7 @@ SECTIONS
 		KEEP(*(.__bss_end));
 	} >.sdram

+	/DISCARD/ : { *(.rela*) }
 	/DISCARD/ : { *(.dynsym) }
 	/DISCARD/ : { *(.dynstr*) }
 	/DISCARD/ : { *(.dynamic*) }
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@ -91,7 +91,7 @@ struct arch_global_data {

 #include <asm-generic/global_data.h>

-#ifdef __clang__
+#if defined(__clang__) || defined(CONFIG_LTO)

 #define DECLARE_GLOBAL_DATA_PTR
 #define gd	get_gd()
@ -122,8 +122,10 @@ static inline void set_gd(volatile gd_t *gd_ptr)
 {
 #ifdef CONFIG_ARM64
 	__asm__ volatile("ldr x18, %0\n" : : "m"(gd_ptr));
-#else
+#elif __ARM_ARCH >= 7
 	__asm__ volatile("ldr r9, %0\n" : : "m"(gd_ptr));
+#else
+	__asm__ volatile("mov r9, %0\n" : : "r"(gd_ptr));
 #endif
 }

--- a/arch/arm/include/asm/secure.h
+++ b/arch/arm/include/asm/secure.h
@ -4,8 +4,8 @@
 #include <config.h>
 #include <asm/global_data.h>

-#define __secure __attribute__ ((section ("._secure.text")))
-#define __secure_data __attribute__ ((section ("._secure.data")))
+#define __secure __section("._secure.text")
+#define __secure_data __section("._secure.data")

 #ifndef __ASSEMBLY__

@ -22,7 +22,7 @@ typedef struct secure_svc_tbl {
 */
 #define DECLARE_SECURE_SVC(_name, _id, _fn) \
 	static const secure_svc_tbl_t __secure_svc_ ## _name \
-		__attribute__((used, section("._secure_svc_tbl_entries"))) \
+		__used __section("._secure_svc_tbl_entries") \
 			 = { \
 				.id = _id, \
 				.func = _fn }
--- a/arch/arm/include/asm/setup.h
+++ b/arch/arm/include/asm/setup.h
@ -235,7 +235,7 @@ struct tagtable {
 	int (*parse)(const struct tag *);
 };

-#define __tag __attribute__((unused, __section__(".taglist")))
+#define __tag __attribute__((unused)) __section(".taglist")
 #define __tagtable(tag, fn) \
 static struct tagtable __tagtable_##fn __tag = { tag, fn }

--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@ -45,6 +45,8 @@ obj-$(CONFIG_SEMIHOSTING) += semihosting.o

 obj-y	+= bdinfo.o
 obj-y	+= sections.o
+CFLAGS_REMOVE_sections.o := $(LTO_CFLAGS)
+
 obj-y	+= stack.o
 ifdef CONFIG_CPU_V7M
 obj-y	+= interrupts_m.o
@ -64,6 +66,7 @@ endif

 obj-y	+= cache.o
 obj-$(CONFIG_SYS_ARM_CACHE_CP15)	+= cache-cp15.o
+CFLAGS_REMOVE_cache-cp15.o := $(LTO_CFLAGS)

 obj-y	+= psci-dt.o

--- a/arch/arm/lib/sections.c
+++ b/arch/arm/lib/sections.c
@ -2,6 +2,7 @@
 /*
 * Copyright 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
 */
+#include <linux/compiler.h>

 /**
 * These two symbols are declared in a C file so that the linker
@ -18,18 +19,18 @@
 * aliasing warnings.
 */

-char __bss_start[0] __attribute__((section(".__bss_start")));
-char __bss_end[0] __attribute__((section(".__bss_end")));
-char __image_copy_start[0] __attribute__((section(".__image_copy_start")));
-char __image_copy_end[0] __attribute__((section(".__image_copy_end")));
-char __rel_dyn_start[0] __attribute__((section(".__rel_dyn_start")));
-char __rel_dyn_end[0] __attribute__((section(".__rel_dyn_end")));
-char __secure_start[0] __attribute__((section(".__secure_start")));
-char __secure_end[0] __attribute__((section(".__secure_end")));
-char __secure_stack_start[0] __attribute__((section(".__secure_stack_start")));
-char __secure_stack_end[0] __attribute__((section(".__secure_stack_end")));
-char __efi_runtime_start[0] __attribute__((section(".__efi_runtime_start")));
-char __efi_runtime_stop[0] __attribute__((section(".__efi_runtime_stop")));
-char __efi_runtime_rel_start[0] __attribute__((section(".__efi_runtime_rel_start")));
-char __efi_runtime_rel_stop[0] __attribute__((section(".__efi_runtime_rel_stop")));
-char _end[0] __attribute__((section(".__end")));
+char __bss_start[0] __section(".__bss_start");
+char __bss_end[0] __section(".__bss_end");
+char __image_copy_start[0] __section(".__image_copy_start");
+char __image_copy_end[0] __section(".__image_copy_end");
+char __rel_dyn_start[0] __section(".__rel_dyn_start");
+char __rel_dyn_end[0] __section(".__rel_dyn_end");
+char __secure_start[0] __section(".__secure_start");
+char __secure_end[0] __section(".__secure_end");
+char __secure_stack_start[0] __section(".__secure_stack_start");
+char __secure_stack_end[0] __section(".__secure_stack_end");
+char __efi_runtime_start[0] __section(".__efi_runtime_start");
+char __efi_runtime_stop[0] __section(".__efi_runtime_stop");
+char __efi_runtime_rel_start[0] __section(".__efi_runtime_rel_start");
+char __efi_runtime_rel_stop[0] __section(".__efi_runtime_rel_stop");
+char _end[0] __section(".__end");
--- a/arch/arm/lib/spl.c
+++ b/arch/arm/lib/spl.c
@ -26,7 +26,7 @@ DECLARE_GLOBAL_DATA_PTR;
 * WARNING: This is going away very soon. Don't use it and don't submit
 * pafches that rely on it. The global_data area is set up in crt0.S.
 */
-gd_t gdata __attribute__ ((section(".data")));
+gd_t gdata __section(".data");
 #endif

 /*
--- a/arch/arm/mach-at91/spl.c
+++ b/arch/arm/mach-at91/spl.c
@ -26,7 +26,7 @@ void at91_disable_wdt(void)
 #include <asm/arch/sama5_boot.h>
 struct {
 	u32	r4;
-} bootrom_stash __attribute__((section(".data")));
+} bootrom_stash __section(".data");

 u32 spl_boot_device(void)
 {
--- a/arch/arm/mach-exynos/spl_boot.c
+++ b/arch/arm/mach-exynos/spl_boot.c
@ -279,7 +279,7 @@ void memzero(void *s, size_t n)
 */
 static void setup_global_data(gd_t *gdp)
 {
-	gd = gdp;
+	set_gd(gdp);
 	memzero((void *)gd, sizeof(gd_t));
 	gd->flags |= GD_FLG_RELOC;
 	gd->baudrate = CONFIG_BAUDRATE;
--- a/arch/arm/mach-imx/imx8m/clock_imx8mm.c
+++ b/arch/arm/mach-imx/imx8m/clock_imx8mm.c
@ -846,7 +846,7 @@ int set_clk_eqos(enum enet_freq type)
 	return 0;
 }

-int imx_eqos_txclk_set_rate(u32 rate)
+int imx_eqos_txclk_set_rate(ulong rate)
 {
 	u32 val;
 	u32 eqos_post_div;
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@ -537,7 +537,7 @@ enum boot_device get_boot_device(void)

 	ret = g_rom_api->query_boot_infor(QUERY_BT_DEV, &boot,
 					  ((uintptr_t)&boot) ^ QUERY_BT_DEV);
-	gd = pgd;
+	set_gd(pgd);

 	if (ret != ROM_API_OKAY) {
 		puts("ROMAPI: failure at query_boot_info\n");
--- a/arch/arm/mach-imx/spl_imx_romapi.c
+++ b/arch/arm/mach-imx/spl_imx_romapi.c
@ -45,7 +45,7 @@ static ulong spl_romapi_read_seekable(struct spl_load_info *load,

 	ret = g_rom_api->download_image(buf, offset, byte,
 					((uintptr_t)buf) ^ offset ^ byte);
-	gd = pgd;
+	set_gd(pgd);

 	if (ret == ROM_API_OKAY)
 		return count;
@ -73,7 +73,7 @@ static int spl_romapi_load_image_seekable(struct spl_image_info *spl_image,
 	ret |= g_rom_api->query_boot_infor(QUERY_IMG_OFF, &image_offset,
 					   ((uintptr_t)&image_offset) ^ QUERY_IMG_OFF);

-	gd = pgd;
+	set_gd(pgd);

 	if (ret != ROM_API_OKAY) {
 		puts("ROMAPI: Failure query boot infor pagesize/offset\n");
@ -94,7 +94,7 @@ static int spl_romapi_load_image_seekable(struct spl_image_info *spl_image,
 	size = ALIGN(sizeof(struct image_header), pagesize);
 	ret = g_rom_api->download_image((u8 *)header, offset, size,
 					((uintptr_t)header) ^ offset ^ size);
-	gd = pgd;
+	set_gd(pgd);

 	if (ret != ROM_API_OKAY) {
 		printf("ROMAPI: download failure offset 0x%x size 0x%x\n",
@ -180,7 +180,7 @@ static int spl_romapi_load_image_stream(struct spl_image_info *spl_image,

 	ret = g_rom_api->query_boot_infor(QUERY_PAGE_SZ, &pagesize,
 					  ((uintptr_t)&pagesize) ^ QUERY_PAGE_SZ);
-	gd = pgd;
+	set_gd(pgd);

 	if (ret != ROM_API_OKAY)
 		puts("failure at query_boot_info\n");
@ -192,7 +192,7 @@ static int spl_romapi_load_image_stream(struct spl_image_info *spl_image,
 	for (i = 0; i < 640; i++) {
 		ret = g_rom_api->download_image(p, 0, pg,
 						((uintptr_t)p) ^ pg);
-		gd = pgd;
+		set_gd(pgd);

 		if (ret != ROM_API_OKAY) {
 			puts("Steam(USB) download failure\n");
@ -213,7 +213,7 @@ static int spl_romapi_load_image_stream(struct spl_image_info *spl_image,

 	if (p - pfit < sizeof(struct fdt_header)) {
 		ret = g_rom_api->download_image(p, 0, pg,  ((uintptr_t)p) ^ pg);
-		gd = pgd;
+		set_gd(pgd);

 		if (ret != ROM_API_OKAY) {
 			puts("Steam(USB) download failure\n");
@ -237,7 +237,7 @@ static int spl_romapi_load_image_stream(struct spl_image_info *spl_image,

 		ret = g_rom_api->download_image(p, 0, imagesize,
 						((uintptr_t)p) ^ imagesize);
-		gd = pgd;
+		set_gd(pgd);

 		p += imagesize;

@ -280,7 +280,7 @@ int board_return_to_bootrom(struct spl_image_info *spl_image,

 	ret = g_rom_api->query_boot_infor(QUERY_BT_DEV, &boot,
 					  ((uintptr_t)&boot) ^ QUERY_BT_DEV);
-	gd =  pgd;
+	set_gd(pgd);

 	if (ret != ROM_API_OKAY) {
 		puts("ROMAPI: failure at query_boot_info\n");
--- a/arch/arm/mach-k3/am642_init.c
+++ b/arch/arm/mach-k3/am642_init.c
@ -44,7 +44,7 @@ static void ctrl_mmr_unlock(void)
 * it to the .data section.
 */
 u32 bootindex __section(".data");
-static struct rom_extended_boot_data bootdata __section(.data);
+static struct rom_extended_boot_data bootdata __section(".data");

 static void store_boot_info_from_rom(void)
 {
--- a/arch/arm/mach-k3/am6_init.c
+++ b/arch/arm/mach-k3/am6_init.c
@ -77,7 +77,7 @@ static void ctrl_mmr_unlock(void)
 * but the .bss is cleared between writing and reading this variable, so move
 * it to the .data section.
 */
-u32 bootindex __attribute__((section(".data")));
+u32 bootindex __section(".data");

 static void store_boot_index_from_rom(void)
 {
--- a/arch/arm/mach-k3/j721e_init.c
+++ b/arch/arm/mach-k3/j721e_init.c
@ -125,8 +125,8 @@ void k3_mmc_restart_clock(void)
 * but the .bss is cleared between writing and reading this variable, so move
 * it to the .data section.
 */
-u32 bootindex __attribute__((section(".data")));
-static struct rom_extended_boot_data bootdata __section(.data);
+u32 bootindex __section(".data");
+static struct rom_extended_boot_data bootdata __section(".data");

 static void store_boot_info_from_rom(void)
 {
--- a/arch/arm/mach-keystone/Makefile
+++ b/arch/arm/mach-keystone/Makefile
@ -9,6 +9,7 @@ obj-y	+= init.o
 obj-y	+= psc.o
 obj-y	+= clock.o
 obj-y	+= mon.o
+CFLAGS_REMOVE_mon.o := $(LTO_CFLAGS)
 ifndef CONFIG_SPL_BUILD
 obj-y	+= cmd_clock.o
 obj-y	+= cmd_mon.o
--- a/arch/arm/mach-mvebu/mbus.c
+++ b/arch/arm/mach-mvebu/mbus.c
@ -98,9 +98,9 @@ struct mvebu_mbus_soc_data {
 };

 struct mvebu_mbus_state mbus_state
-	__attribute__ ((section(".data")));
+	__section(".data");
 static struct mbus_dram_target_info mbus_dram_info
-	__attribute__ ((section(".data")));
+	__section(".data");

 /*
 * Functions to manipulate the address decoding windows
--- a/arch/arm/mach-mvebu/timer.c
+++ b/arch/arm/mach-mvebu/timer.c
@ -14,7 +14,7 @@

 #define TIMER_LOAD_VAL			0xffffffff

-static int init_done __attribute__((section(".data"))) = 0;
+static int init_done __section(".data") = 0;

 /*
 * Timer initialization
--- a/arch/arm/mach-nexell/clock.c
+++ b/arch/arm/mach-nexell/clock.c
@ -99,7 +99,7 @@ static const char * const clk_core[] = {
 * in board_init_f(), respectively! I.e. global variables can not be used!
 */
 static struct clk_dev_peri clk_periphs[]
-	__attribute__((section(".data"))) = {
+	__section(".data") = {
 	CLK_PERI_1S(DEV_NAME_TIMER,	0,	CLK_ID_TIMER_0,
 		    PHY_BASEADDR_CLKGEN14, (I_PLL_0_2)),
 	CLK_PERI_1S(DEV_NAME_TIMER,	1,	CLK_ID_TIMER_1,
@ -167,7 +167,7 @@ static struct clk_dev_peri clk_periphs[]
 #define	MAX_DIVIDER		((1 << 8) - 1)	/* 256, align 2 */

 static struct clk_dev		st_clk_devs[CLK_DEVS_NUM]
-				__attribute__((section(".data")));
+				__section(".data");
 #define	clk_dev_get(n)		((struct clk_dev *)&st_clk_devs[n])
 #define	clk_container(p)	(container_of(p, struct clk_dev, clk))

@ -196,7 +196,7 @@ struct _core_hz_ {
 * in board_init_f(), respectively! I.e. global variables can not be used!
 */
 /* core clock */
-static struct _core_hz_ core_hz __attribute__((section(".data")));
+static struct _core_hz_ core_hz __section(".data");

 #define	CORE_HZ_SIZE	(sizeof(core_hz) / 4)

--- a/arch/arm/mach-nexell/timer.c
+++ b/arch/arm/mach-nexell/timer.c
@ -23,9 +23,9 @@
 * Section ".data" must be used because BSS is not available before relocation,
 * in board_init_f(), respectively! I.e. global variables can not be used!
 */
-static unsigned long timestamp __attribute__ ((section(".data")));
-static unsigned long lastdec __attribute__ ((section(".data")));
-static int	timerinit __attribute__ ((section(".data")));
+static unsigned long timestamp __section(".data");
+static unsigned long lastdec __section(".data");
+static int	timerinit __section(".data");

 /* macro to hw timer tick config */
 static long	TIMER_FREQ  = 1000000;
--- a/arch/arm/mach-omap2/omap3/Makefile
+++ b/arch/arm/mach-omap2/omap3/Makefile
@ -9,6 +9,7 @@ CFLAGS_clock.o += -marm
 obj-y	:= lowlevel_init.o

 obj-y	+= board.o
+CFLAGS_REMOVE_board.o := $(LTO_CFLAGS)
 obj-y	+= boot.o
 obj-y	+= clock.o
 obj-y	+= sys_info.o
--- a/arch/arm/mach-rockchip/board.c
+++ b/arch/arm/mach-rockchip/board.c
@ -139,7 +139,7 @@ static struct dwc3_device dwc3_device_data = {
 	.hsphy_mode = USBPHY_INTERFACE_MODE_UTMIW,
 };

-int usb_gadget_handle_interrupts(void)
+int usb_gadget_handle_interrupts(int index)
 {
 	dwc3_uboot_handle_interrupt(0);
 	return 0;
--- a/arch/arm/mach-socfpga/spl_a10.c
+++ b/arch/arm/mach-socfpga/spl_a10.c
@ -40,7 +40,7 @@ DECLARE_GLOBAL_DATA_PTR;
 					 SOCFPGA_PHYS_OCRAM_SIZE - \
 					 BOOTROM_SHARED_MEM_SIZE)
 #define RST_STATUS_SHARED_ADDR		(BOOTROM_SHARED_MEM_ADDR + 0x438)
-static u32 rst_mgr_status __section(.data);
+static u32 rst_mgr_status __section(".data");

 /*
 * Bootrom will clear the status register in reset manager and stores the
--- a/arch/arm/mach-sunxi/board.c
+++ b/arch/arm/mach-sunxi/board.c
@ -39,7 +39,7 @@ struct fel_stash {
 	uint32_t cr;
 };

-struct fel_stash fel_stash __attribute__((section(".data")));
+struct fel_stash fel_stash __section(".data");

 #ifdef CONFIG_ARM64
 #include <asm/armv8/mmu.h>
--- a/arch/arm/mach-tegra/board.c
+++ b/arch/arm/mach-tegra/board.c
@ -45,7 +45,7 @@ enum {
 	UART_COUNT = 5,
 };

-static bool from_spl __attribute__ ((section(".data")));
+static bool from_spl __section(".data");

 #ifndef CONFIG_SPL_BUILD
 void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2,
--- a/arch/arm/mach-tegra/cboot.c
+++ b/arch/arm/mach-tegra/cboot.c
@ -49,7 +49,7 @@ extern struct mm_region tegra_mem_map[];
 */

 /* The number of valid entries in ram_banks[] */
-static int ram_bank_count __attribute__((section(".data")));
+static int ram_bank_count __section(".data");

 /*
 * The usable top-of-RAM for U-Boot. This is both:
@ -57,15 +57,15 @@ static int ram_bank_count __attribute__((section(".data")));
 * b) At the end of a region that has enough space to hold the relocated U-Boot
 *    and all other allocations made around it (stack, heap, page tables, etc.)
 */
-static u64 ram_top __attribute__((section(".data")));
+static u64 ram_top __section(".data");
 /* The base address of the region of RAM that ends at ram_top */
-static u64 region_base __attribute__((section(".data")));
+static u64 region_base __section(".data");

 /*
 * Explicitly put this in the .data section because it is written before the
 * .bss section is zeroed out but it needs to persist.
 */
-unsigned long cboot_boot_x0 __attribute__((section(".data")));
+unsigned long cboot_boot_x0 __section(".data");

 void cboot_save_boot_params(unsigned long x0, unsigned long x1,
 			    unsigned long x2, unsigned long x3)
--- a/arch/arm/mach-tegra/tegra20/Makefile
+++ b/arch/arm/mach-tegra/tegra20/Makefile
@ -10,6 +10,7 @@ endif
 # flags for any startup files it might use.
 CFLAGS_warmboot_avp.o = -march=armv4t -U__LINUX_ARM_ARCH__ \
 	-D__LINUX_ARM_ARCH__=4
+CFLAGS_REMOVE_warmboot_avp.o := $(LTO_CFLAGS)

 obj-y	+= clock.o funcmux.o pinmux.o
 obj-$(CONFIG_TEGRA_LP0) += warmboot.o crypto.o warmboot_avp.o
--- a/arch/mips/mach-jz47xx/jz4780/jz4780.c
+++ b/arch/mips/mach-jz47xx/jz4780/jz4780.c
@ -23,7 +23,7 @@
 #ifdef CONFIG_SPL_BUILD
 /* Pointer to the global data structure for SPL */
 DECLARE_GLOBAL_DATA_PTR;
-gd_t gdata __attribute__ ((section(".bss")));
+gd_t gdata __section(".bss");

 void board_init_f(ulong dummy)
 {
--- a/arch/nds32/include/asm/setup.h
+++ b/arch/nds32/include/asm/setup.h
@ -155,7 +155,7 @@ struct tagtable {

 #ifdef __KERNEL__

-#define __tag __used __attribute__((__section__(".taglist")))
+#define __tag __used __section(".taglist")
 #define __tagtable(tag, fn) \
 static struct tagtable __tagtable_##fn __tag = { tag, fn }

@ -182,8 +182,8 @@ struct early_params {
 };

 #define __early_param(name, fn)					\
-static struct early_params __early_##fn __used	\
-__attribute__((__section__("__early_param"))) = { name, fn }
+static struct early_params __early_##fn __used			\
+__section("__early_param") = { name, fn }

 #endif
 #endif
--- a/arch/powerpc/include/asm/cache.h
+++ b/arch/powerpc/include/asm/cache.h
@ -41,8 +41,8 @@
 #define __cacheline_aligned __attribute__((__aligned__(L1_CACHE_BYTES)))
 #else
 #define __cacheline_aligned					\
-  __attribute__((__aligned__(L1_CACHE_BYTES),			\
-		 __section__(".data.cacheline_aligned")))
+  __attribute__((__aligned__(L1_CACHE_BYTES)))			\
+  __section(".data.cacheline_aligned")
 #endif

 #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
--- a/arch/riscv/cpu/cpu.c
+++ b/arch/riscv/cpu/cpu.c
@ -17,10 +17,10 @@
 * before the bss section is available.
 */
 #ifdef CONFIG_OF_PRIOR_STAGE
-phys_addr_t prior_stage_fdt_address __attribute__((section(".data")));
+phys_addr_t prior_stage_fdt_address __section(".data");
 #endif
 #ifndef CONFIG_XIP
-u32 hart_lottery __attribute__((section(".data"))) = 0;
+u32 hart_lottery __section(".data") = 0;

 /*
 * The main hart running U-Boot has acquired available_harts_lock until it has
--- a/arch/sandbox/config.mk
+++ b/arch/sandbox/config.mk
@ -17,13 +17,21 @@ PLATFORM_CPPFLAGS += $(shell $(SDL_CONFIG) --cflags)
 endif

 cmd_u-boot__ = $(CC) -o $@ -Wl,-T u-boot.lds $(u-boot-init) \
-	-Wl,--start-group $(u-boot-main) -Wl,--end-group \
+	$(LTO_FINAL_LDFLAGS) \
+	-Wl,--whole-archive \
+		$(u-boot-main) \
+		$(u-boot-keep-syms-lto) \
+	-Wl,--no-whole-archive \
 	$(PLATFORM_LIBS) -Wl,-Map -Wl,u-boot.map

 cmd_u-boot-spl = (cd $(obj) && $(CC) -o $(SPL_BIN) -Wl,-T u-boot-spl.lds \
+	$(LTO_FINAL_LDFLAGS) \
 	$(patsubst $(obj)/%,%,$(u-boot-spl-init)) \
-	-Wl,--start-group $(patsubst $(obj)/%,%,$(u-boot-spl-main)) \
-	$(patsubst $(obj)/%,%,$(u-boot-spl-platdata)) -Wl,--end-group \
+	-Wl,--whole-archive \
+		$(patsubst $(obj)/%,%,$(u-boot-spl-main)) \
+		$(patsubst $(obj)/%,%,$(u-boot-spl-platdata)) \
+		$(patsubst $(obj)/%,%,$(u-boot-spl-keep-syms-lto)) \
+	-Wl,--no-whole-archive \
 	$(PLATFORM_LIBS) -Wl,-Map -Wl,u-boot-spl.map -Wl,--gc-sections)

 CONFIG_ARCH_DEVICE_TREE := sandbox
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@ -375,7 +375,8 @@ static struct option *long_opts;

 int os_parse_args(struct sandbox_state *state, int argc, char *argv[])
 {
-	struct sandbox_cmdline_option **sb_opt = __u_boot_sandbox_option_start;
+	struct sandbox_cmdline_option **sb_opt =
+		__u_boot_sandbox_option_start();
 	size_t num_options = __u_boot_sandbox_option_count();
 	size_t i;

--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@ -58,7 +58,8 @@ static int h_compare_opt(const void *p1, const void *p2)
 int sandbox_early_getopt_check(void)
 {
 	struct sandbox_state *state = state_get_current();
-	struct sandbox_cmdline_option **sb_opt = __u_boot_sandbox_option_start;
+	struct sandbox_cmdline_option **sb_opt =
+		__u_boot_sandbox_option_start();
 	size_t num_options = __u_boot_sandbox_option_count();
 	size_t i;
 	int max_arg_len, max_noarg_len;
--- a/arch/sandbox/cpu/u-boot-spl.lds
+++ b/arch/sandbox/cpu/u-boot-spl.lds
@ -21,9 +21,11 @@ SECTIONS
 		__priv_data_end = .;
 	}

-	__u_boot_sandbox_option_start = .;
-	_u_boot_sandbox_getopt : { KEEP(*(.u_boot_sandbox_getopt)) }
-	__u_boot_sandbox_option_end = .;
+	_u_boot_sandbox_getopt : {
+		*(.u_boot_sandbox_getopt_start)
+		KEEP(*(.u_boot_sandbox_getopt))
+		*(.u_boot_sandbox_getopt_end)
+	}
 }

 INSERT AFTER .data;
--- a/arch/sandbox/cpu/u-boot.lds
+++ b/arch/sandbox/cpu/u-boot.lds
@ -13,9 +13,11 @@ SECTIONS
 		KEEP(*(SORT(.u_boot_list*)));
 	}

-	__u_boot_sandbox_option_start = .;
-	_u_boot_sandbox_getopt : { *(.u_boot_sandbox_getopt) }
-	__u_boot_sandbox_option_end = .;
+	_u_boot_sandbox_getopt : {
+		*(.u_boot_sandbox_getopt_start)
+		*(.u_boot_sandbox_getopt)
+		*(.u_boot_sandbox_getopt_end)
+	}

 	.__efi_runtime_start : {
 		*(.__efi_runtime_start)
--- a/arch/sandbox/include/asm/getopt.h
+++ b/arch/sandbox/include/asm/getopt.h
@ -44,7 +44,7 @@ struct sandbox_cmdline_option {
 		.callback = sandbox_cmdline_cb_##f, \
 	}; \
 	/* Ppointer to the struct in a special section for the linker script */ \
-	static __attribute__((section(".u_boot_sandbox_getopt"), used)) \
+	static __used __section(".u_boot_sandbox_getopt") \
 		struct sandbox_cmdline_option \
 			*sandbox_cmdline_option_##f##_ptr = \
 			&sandbox_cmdline_option_##f
--- a/arch/sandbox/include/asm/sections.h
+++ b/arch/sandbox/include/asm/sections.h
@ -13,12 +13,27 @@

 struct sandbox_cmdline_option;

-extern struct sandbox_cmdline_option *__u_boot_sandbox_option_start[],
-	*__u_boot_sandbox_option_end[];
+static inline struct sandbox_cmdline_option **
+__u_boot_sandbox_option_start(void)
+{
+	static char start[0] __aligned(4) __attribute__((unused))
+		__section(".u_boot_sandbox_getopt_start");
+
+	return (struct sandbox_cmdline_option **)&start;
+}
+
+static inline struct sandbox_cmdline_option **
+__u_boot_sandbox_option_end(void)
+{
+	static char end[0] __aligned(4) __attribute__((unused))
+		__section(".u_boot_sandbox_getopt_end");
+
+	return (struct sandbox_cmdline_option **)&end;
+}

 static inline size_t __u_boot_sandbox_option_count(void)
 {
-	return __u_boot_sandbox_option_end - __u_boot_sandbox_option_start;
+	return __u_boot_sandbox_option_end() - __u_boot_sandbox_option_start();
 }

 #endif
--- a/arch/sandbox/lib/sections.c
+++ b/arch/sandbox/lib/sections.c
@ -3,10 +3,11 @@
 * Copyright 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
 *
 */
+#include <linux/compiler.h>

-char __efi_runtime_start[0] __attribute__((section(".__efi_runtime_start")));
-char __efi_runtime_stop[0] __attribute__((section(".__efi_runtime_stop")));
+char __efi_runtime_start[0] __section(".__efi_runtime_start");
+char __efi_runtime_stop[0] __section(".__efi_runtime_stop");
 char __efi_runtime_rel_start[0]
-		__attribute__((section(".__efi_runtime_rel_start")));
+		__section(".__efi_runtime_rel_start");
 char __efi_runtime_rel_stop[0]
-		__attribute__((section(".__efi_runtime_rel_stop")));
+		__section(".__efi_runtime_rel_stop");
--- a/arch/x86/cpu/coreboot/timestamp.c
+++ b/arch/x86/cpu/coreboot/timestamp.c
@ -11,7 +11,7 @@
 #include <asm/cb_sysinfo.h>
 #include <linux/compiler.h>

-static struct timestamp_table *ts_table  __attribute__((section(".data")));
+static struct timestamp_table *ts_table  __section(".data");

 void timestamp_init(void)
 {
--- a/arch/x86/lib/coreboot/cb_sysinfo.c
+++ b/arch/x86/lib/coreboot/cb_sysinfo.c
@ -21,7 +21,7 @@ DECLARE_GLOBAL_DATA_PTR;
 * with zeroes when transitioning from "ROM", which is really RAM, to other
 * RAM.
 */
-struct sysinfo_t lib_sysinfo __attribute__((section(".data")));
+struct sysinfo_t lib_sysinfo __section(".data");

 /*
 * Some of this is x86 specific, and the rest of it is generic. Right now,
--- a/arch/x86/lib/sections.c
+++ b/arch/x86/lib/sections.c
@ -2,10 +2,11 @@
 /*
 * Copyright 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
 */
+#include <linux/compiler.h>

-char __efi_runtime_start[0] __attribute__((section(".__efi_runtime_start")));
-char __efi_runtime_stop[0] __attribute__((section(".__efi_runtime_stop")));
+char __efi_runtime_start[0] __section(".__efi_runtime_start");
+char __efi_runtime_stop[0] __section(".__efi_runtime_stop");
 char __efi_runtime_rel_start[0]
-		__attribute__((section(".__efi_runtime_rel_start")));
+		__section(".__efi_runtime_rel_start");
 char __efi_runtime_rel_stop[0]
-		__attribute__((section(".__efi_runtime_rel_stop")));
+		__section(".__efi_runtime_rel_stop");
--- a/arch/xtensa/cpu/cpu.c
+++ b/arch/xtensa/cpu/cpu.c
@ -20,7 +20,7 @@

 DECLARE_GLOBAL_DATA_PTR;

-gd_t *gd __attribute__((section(".data")));
+gd_t *gd __section(".data");

 #if defined(CONFIG_DISPLAY_CPUINFO)
 /*
--- a/board/bosch/shc/board.c
+++ b/board/bosch/shc/board.c
@ -45,7 +45,7 @@

 DECLARE_GLOBAL_DATA_PTR;

-static struct shc_eeprom __attribute__((section(".data"))) header;
+static struct shc_eeprom __section(".data") header;
 static int shc_eeprom_valid;

 /*
--- a/board/broadcom/bcmstb/bcmstb.c
+++ b/board/broadcom/bcmstb/bcmstb.c
@ -22,7 +22,7 @@

 DECLARE_GLOBAL_DATA_PTR;

-#define BCMSTB_DATA_SECTION __attribute__((section(".data")))
+#define BCMSTB_DATA_SECTION __section(".data")

 struct bcmstb_boot_parameters bcmstb_boot_parameters BCMSTB_DATA_SECTION;

--- a/board/samsung/arndale/arndale_spl.c
+++ b/board/samsung/arndale/arndale_spl.c
@ -10,7 +10,7 @@

 /* Parameters of early board initialization in SPL */
 static struct spl_machine_param machine_param
-		__attribute__((section(".machine_param"))) = {
+		__section(".machine_param") = {
 	.signature	= SIGNATURE,
 	.version	= 1,
 	.params		= "vmubfasirM",
--- a/board/samsung/common/exynos5-dt.c
+++ b/board/samsung/common/exynos5-dt.c
@ -126,7 +126,7 @@ static struct dwc3_device dwc3_device_data = {
 	.index = 0,
 };

-int usb_gadget_handle_interrupts(void)
+int usb_gadget_handle_interrupts(int index)
 {
 	dwc3_uboot_handle_interrupt(0);
 	return 0;
--- a/board/samsung/smdk5250/smdk5250_spl.c
+++ b/board/samsung/smdk5250/smdk5250_spl.c
@ -12,7 +12,7 @@

 /* Parameters of early board initialization in SPL */
 static struct spl_machine_param machine_param
-		__attribute__((section(".machine_param"))) = {
+		__section(".machine_param") = {
 	.signature	= SIGNATURE,
 	.version	= 1,
 	.params		= "vmubfasirM",
--- a/board/samsung/smdk5420/smdk5420_spl.c
+++ b/board/samsung/smdk5420/smdk5420_spl.c
@ -12,7 +12,7 @@

 /* Parameters of early board initialization in SPL */
 static struct spl_machine_param machine_param
-		__attribute__((section(".machine_param"))) = {
+		__section(".machine_param") = {
 	.signature	= SIGNATURE,
 	.version	= 1,
 	.params		= "vmubfasirM",
--- a/board/siemens/draco/board.c
+++ b/board/siemens/draco/board.c
@ -41,7 +41,7 @@
 #include <nand.h>

 #ifdef CONFIG_SPL_BUILD
-static struct draco_baseboard_id __attribute__((section(".data"))) settings;
+static struct draco_baseboard_id __section(".data") settings;

 #if DDR_PLL_FREQ == 303
 #if !defined(CONFIG_TARGET_ETAMIN)
--- a/board/xilinx/common/fru_ops.c
+++ b/board/xilinx/common/fru_ops.c
@ -14,7 +14,7 @@

 #include "fru.h"

-struct fru_table fru_data __section(.data);
+struct fru_table fru_data __section(".data");

 static u16 fru_cal_area_len(u8 len)
 {
--- a/cmd/stackprot_test.c
+++ b/cmd/stackprot_test.c
@ -9,9 +9,16 @@
 static int do_test_stackprot_fail(struct cmd_tbl *cmdtp, int flag, int argc,
 				  char *const argv[])
 {
+	/*
+	 * In order to avoid having the compiler optimize away the stack smashing
+	 * we need to do a little something here.
+	 */
 	char a[128];

 	memset(a, 0xa5, 512);
+
+	printf("We have smashed our stack as this should not exceed 128: sizeof(a) = %ld\n", strlen(a));
+
 	return 0;
 }

--- a/configs/am3517_evm_defconfig
+++ b/configs/am3517_evm_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 # CONFIG_SPL_USE_ARCH_MEMCPY is not set
 # CONFIG_SPL_USE_ARCH_MEMSET is not set
--- a/configs/da850evm_defconfig
+++ b/configs/da850evm_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_SYS_THUMB_BUILD=y
 CONFIG_ARCH_DAVINCI=y
--- a/configs/da850evm_direct_nor_defconfig
+++ b/configs/da850evm_direct_nor_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_CPU_INIT=y
 CONFIG_ARCH_DAVINCI=y
--- a/configs/da850evm_nand_defconfig
+++ b/configs/da850evm_nand_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_SYS_THUMB_BUILD=y
 CONFIG_ARCH_DAVINCI=y
--- a/configs/imx6q_logic_defconfig
+++ b/configs/imx6q_logic_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_MX6=y
 CONFIG_SYS_TEXT_BASE=0x17800000
--- a/configs/imx8mm_beacon_defconfig
+++ b/configs/imx8mm_beacon_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_IMX8M=y
 CONFIG_SYS_TEXT_BASE=0x40200000
--- a/configs/imx8mm_venice_defconfig
+++ b/configs/imx8mm_venice_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_IMX8M=y
 CONFIG_SYS_TEXT_BASE=0x40200000
--- a/configs/imx8mn_beacon_2g_defconfig
+++ b/configs/imx8mn_beacon_2g_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_IMX8M=y
 CONFIG_SYS_TEXT_BASE=0x40200000
--- a/configs/imx8mn_beacon_defconfig
+++ b/configs/imx8mn_beacon_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_IMX8M=y
 CONFIG_SYS_TEXT_BASE=0x40200000
--- a/configs/nokia_rx51_defconfig
+++ b/configs/nokia_rx51_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 # CONFIG_SYS_THUMB_BUILD is not set
 CONFIG_ARCH_OMAP2PLUS=y
--- a/configs/omap3_logic_defconfig
+++ b/configs/omap3_logic_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 # CONFIG_SPL_USE_ARCH_MEMCPY is not set
 # CONFIG_SPL_USE_ARCH_MEMSET is not set
--- a/configs/r8a774a1_beacon_defconfig
+++ b/configs/r8a774a1_beacon_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_RMOBILE=y
 CONFIG_SYS_TEXT_BASE=0x50000000
--- a/configs/r8a774b1_beacon_defconfig
+++ b/configs/r8a774b1_beacon_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_RMOBILE=y
 CONFIG_SYS_TEXT_BASE=0x50000000
--- a/configs/r8a774e1_beacon_defconfig
+++ b/configs/r8a774e1_beacon_defconfig
@ -1,3 +1,4 @@
+CONFIG_LTO=y
 CONFIG_ARM=y
 CONFIG_ARCH_RMOBILE=y
 CONFIG_SYS_TEXT_BASE=0x50000000
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@ -110,7 +110,7 @@ static int waiting_for_cmd_completed(void __iomem *offset,
 	return (i < timeout_msec) ? 0 : -1;
 }

-int __weak ahci_link_up(struct ahci_uc_priv *uc_priv, u8 port)
+int __weak ahci_link_up(struct ahci_uc_priv *uc_priv, int port)
 {
 	u32 tmp;
 	int j = 0;
--- a/drivers/bios_emulator/biosemu.c
+++ b/drivers/bios_emulator/biosemu.c
@ -50,7 +50,7 @@
 #include "biosemui.h"

 BE_sysEnv _BE_env = {{0}};
-static X86EMU_memFuncs _BE_mem __attribute__((section(GOT2_TYPE))) = {
+static X86EMU_memFuncs _BE_mem __section(GOT2_TYPE) = {
 	BE_rdb,
 	BE_rdw,
 	BE_rdl,
@ -59,7 +59,7 @@ static X86EMU_memFuncs _BE_mem __attribute__((section(GOT2_TYPE))) = {
 	BE_wrl,
 	};

-static X86EMU_pioFuncs _BE_pio __attribute__((section(GOT2_TYPE))) = {
+static X86EMU_pioFuncs _BE_pio __section(GOT2_TYPE) = {
 	BE_inb,
 	BE_inw,
 	BE_inl,
--- a/drivers/clk/kendryte/clk.c
+++ b/drivers/clk/kendryte/clk.c
@ -347,7 +347,7 @@ static const struct k210_comp_params k210_comps[] = {
 #undef COMP_NOMUX_ID
 #undef COMP_LIST

-static struct clk *k210_bypass_children __section(.data);
+static struct clk *k210_bypass_children __section(".data");

 /* Helper functions to create sub-clocks */
 static struct clk_mux *k210_create_mux(const struct k210_mux_params *params,
@ -473,7 +473,7 @@ cleanup_mux:
 	return comp;
 }

-static bool __section(.data) probed;
+static bool __section(".data") probed;

 /* reset probed so we will probe again post-relocation */
 static int k210_clk_bind(struct udevice *dev)
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@ -435,7 +435,36 @@ int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)

 int regmap_read(struct regmap *map, uint offset, uint *valp)
 {
-	return regmap_raw_read(map, offset, valp, map->width);
+	union {
+		u8 v8;
+		u16 v16;
+		u32 v32;
+		u64 v64;
+	} u;
+	int res;
+
+	res = regmap_raw_read(map, offset, &u, map->width);
+	if (res)
+		return res;
+
+	switch (map->width) {
+	case REGMAP_SIZE_8:
+		*valp = u.v8;
+		break;
+	case REGMAP_SIZE_16:
+		*valp = u.v16;
+		break;
+	case REGMAP_SIZE_32:
+		*valp = u.v32;
+		break;
+	case REGMAP_SIZE_64:
+		*valp = u.v64;
+		break;
+	default:
+		unreachable();
+	}
+
+	return 0;
 }

 static inline void __write_8(u8 *addr, const u8 *val,
@ -546,7 +575,33 @@ int regmap_raw_write(struct regmap *map, uint offset, const void *val,

 int regmap_write(struct regmap *map, uint offset, uint val)
 {
-	return regmap_raw_write(map, offset, &val, map->width);
+	union {
+		u8 v8;
+		u16 v16;
+		u32 v32;
+		u64 v64;
+	} u;
+
+	switch (map->width) {
+	case REGMAP_SIZE_8:
+		u.v8 = val;
+		break;
+	case REGMAP_SIZE_16:
+		u.v16 = val;
+		break;
+	case REGMAP_SIZE_32:
+		u.v32 = val;
+		break;
+	case REGMAP_SIZE_64:
+		u.v64 = val;
+		break;
+	default:
+		debug("%s: regmap size %zu unknown\n", __func__,
+		      (size_t)map->width);
+		return -EINVAL;
+	}
+
+	return regmap_raw_write(map, offset, &u, map->width);
 }

 int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@ -42,7 +42,7 @@
 #if CONFIG_IS_ENABLED(EFI_LOADER)
 int __efi_runtime_data psci_method;
 #else
-int psci_method __attribute__ ((section(".data")));
+int psci_method __section(".data");
 #endif

 unsigned long __efi_runtime invoke_psci_fn
--- a/drivers/mtd/nand/raw/mxc_nand_spl.c
+++ b/drivers/mtd/nand/raw/mxc_nand_spl.c
@ -326,7 +326,7 @@ int nand_spl_load_image(uint32_t from, unsigned int size, void *buf)
 * configured and available since this code loads the main U-Boot image
 * from NAND into SDRAM and starts it from there.
 */
-void nand_boot(void)
+__used void nand_boot(void)
 {
 	__attribute__((noreturn)) void (*uboot)(void);

--- a/drivers/pinctrl/nxp/pinctrl-imx5.c
+++ b/drivers/pinctrl/nxp/pinctrl-imx5.c
@ -10,7 +10,7 @@

 #include "pinctrl-imx.h"

-static struct imx_pinctrl_soc_info imx5_pinctrl_soc_info __attribute__((section(".data")));
+static struct imx_pinctrl_soc_info imx5_pinctrl_soc_info __section(".data");

 static int imx5_pinctrl_probe(struct udevice *dev)
 {
--- a/drivers/pinctrl/nxp/pinctrl-imx7.c
+++ b/drivers/pinctrl/nxp/pinctrl-imx7.c
@ -9,7 +9,7 @@

 #include "pinctrl-imx.h"

-static struct imx_pinctrl_soc_info imx7_pinctrl_soc_info __attribute__((section(".data")));
+static struct imx_pinctrl_soc_info imx7_pinctrl_soc_info __section(".data");

 static struct imx_pinctrl_soc_info imx7_lpsr_pinctrl_soc_info = {
 	.flags = ZERO_OFFSET_VALID,
--- a/drivers/pinctrl/nxp/pinctrl-imx8m.c
+++ b/drivers/pinctrl/nxp/pinctrl-imx8m.c
@ -8,7 +8,7 @@

 #include "pinctrl-imx.h"

-static struct imx_pinctrl_soc_info imx8mq_pinctrl_soc_info __attribute__((section(".data")));
+static struct imx_pinctrl_soc_info imx8mq_pinctrl_soc_info __section(".data");

 static int imx8mq_pinctrl_probe(struct udevice *dev)
 {
--- a/drivers/power/pmic/pmic_tps62362.c
+++ b/drivers/power/pmic/pmic_tps62362.c
@ -11,7 +11,7 @@
 #include <power/tps62362.h>

 #if CONFIG_IS_ENABLED(DM_I2C)
-struct udevice *tps62362_dev __attribute__((section(".data"))) = NULL;
+struct udevice *tps62362_dev __section(".data") = NULL;
 #endif

 /**
--- a/drivers/power/pmic/pmic_tps65217.c
+++ b/drivers/power/pmic/pmic_tps65217.c
@ -8,7 +8,7 @@
 #include <i2c.h>
 #include <power/tps65217.h>

-struct udevice *tps65217_dev __attribute__((section(".data"))) = NULL;
+struct udevice *tps65217_dev __section(".data") = NULL;

 /**
 * tps65217_reg_read() - Generic function that can read a TPS65217 register
--- a/drivers/power/pmic/pmic_tps65218.c
+++ b/drivers/power/pmic/pmic_tps65218.c
@ -86,7 +86,7 @@ int tps65218_reg_write(uchar prot_level, uchar dest_reg, uchar dest_val,
 	return 0;
 }
 #else
-struct udevice *tps65218_dev __attribute__((section(".data"))) = NULL;
+struct udevice *tps65218_dev __section(".data") = NULL;

 int tps65218_reg_read(uchar dest_reg, uchar *dest_val)
 {
--- a/drivers/power/pmic/pmic_tps65910.c
+++ b/drivers/power/pmic/pmic_tps65910.c
@ -8,7 +8,7 @@
 #include <i2c.h>
 #include <power/tps65910.h>

-struct udevice *tps65910_dev __attribute__((section(".data"))) = NULL;
+struct udevice *tps65910_dev __section(".data") = NULL;

 static inline int tps65910_read_reg(int addr, uchar *buf)
 {
--- a/drivers/serial/serial_pl01x.c
+++ b/drivers/serial/serial_pl01x.c
@ -30,8 +30,8 @@ DECLARE_GLOBAL_DATA_PTR;
 #ifndef CONFIG_DM_SERIAL

 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
-static enum pl01x_type pl01x_type __attribute__ ((section(".data")));
-static struct pl01x_regs *base_regs __attribute__ ((section(".data")));
+static enum pl01x_type pl01x_type __section(".data");
+static struct pl01x_regs *base_regs __section(".data");
 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))

 #endif
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@ -217,8 +217,8 @@ extern const efi_guid_t efi_guid_firmware_management_protocol;
 /* GUID for the ESRT */
 extern const efi_guid_t efi_esrt_guid;

-extern unsigned int __efi_runtime_start, __efi_runtime_stop;
-extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
+extern char __efi_runtime_start[], __efi_runtime_stop[];
+extern char __efi_runtime_rel_start[], __efi_runtime_rel_stop[];

 /**
 * struct efi_open_protocol_info_item - open protocol info item
@ -678,12 +678,51 @@ ssize_t efi_dp_check_length(const struct efi_device_path *dp,
 	(((_dp)->type == DEVICE_PATH_TYPE_##_type) && \
 	 ((_dp)->sub_type == DEVICE_PATH_SUB_TYPE_##_subtype))

-/*
- * Use these to indicate that your code / data should go into the EFI runtime
- * section and thus still be available when the OS is running
+/**
+ * __efi_runtime_data - declares a non-const variable for EFI runtime section
+ *
+ * This macro indicates that a variable is non-const and should go into the
+ * EFI runtime section, and thus still be available when the OS is running.
+ *
+ * Only use on variables not declared const.
+ *
+ * Example:
+ *
+ * ::
+ *
+ *   static __efi_runtime_data my_computed_table[256];
 */
-#define __efi_runtime_data __attribute__ ((section (".data.efi_runtime")))
-#define __efi_runtime __attribute__ ((section (".text.efi_runtime")))
+#define __efi_runtime_data __section(".data.efi_runtime")
+
+/**
+ * __efi_runtime_rodata - declares a read-only variable for EFI runtime section
+ *
+ * This macro indicates that a variable is read-only (const) and should go into
+ * the EFI runtime section, and thus still be available when the OS is running.
+ *
+ * Only use on variables also declared const.
+ *
+ * Example:
+ *
+ * ::
+ *
+ *   static const __efi_runtime_rodata my_const_table[] = { 1, 2, 3 };
+ */
+#define __efi_runtime_rodata __section(".rodata.efi_runtime")
+
+/**
+ * __efi_runtime - declares a function for EFI runtime section
+ *
+ * This macro indicates that a function should go into the EFI runtime section,
+ * and thus still be available when the OS is running.
+ *
+ * Example:
+ *
+ * ::
+ *
+ *   static __efi_runtime compute_my_table(void);
+ */
+#define __efi_runtime __section(".text.efi_runtime")

 /* Indicate supported runtime services */
 efi_status_t efi_init_runtime_supported(void);
@ -888,6 +927,7 @@ efi_status_t efi_launch_capsules(void);

 /* Without CONFIG_EFI_LOADER we don't have a runtime section, stub it out */
 #define __efi_runtime_data
+#define __efi_runtime_rodata
 #define __efi_runtime
 static inline efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
 {
--- a/include/errno.h
+++ b/include/errno.h
@ -8,7 +8,13 @@

 #include <linux/errno.h>

-extern int errno;
+#ifdef __SANDBOX__
+#define __errno_asm_label asm("__u_boot_errno")
+#else
+#define __errno_asm_label
+#endif
+
+extern int errno __errno_asm_label;

 #define __set_errno(val) do { errno = val; } while (0)

--- a/include/linker_lists.h
+++ b/include/linker_lists.h
@ -69,8 +69,8 @@
 */
 #define ll_entry_declare(_type, _name, _list)				\
 	_type _u_boot_list_2_##_list##_2_##_name __aligned(4)		\
-			__attribute__((unused,				\
-			section(".u_boot_list_2_"#_list"_2_"#_name)))
+			__attribute__((unused))				\
+			__section(".u_boot_list_2_"#_list"_2_"#_name)

 /**
 * ll_entry_declare_list() - Declare a list of link-generated array entries
@ -92,8 +92,8 @@
 */
 #define ll_entry_declare_list(_type, _name, _list)			\
 	_type _u_boot_list_2_##_list##_2_##_name[] __aligned(4)		\
-			__attribute__((unused,				\
-			section(".u_boot_list_2_"#_list"_2_"#_name)))
+			__attribute__((unused))				\
+			__section(".u_boot_list_2_"#_list"_2_"#_name)

 /*
 * We need a 0-byte-size type for iterator symbols, and the compiler
@ -125,8 +125,8 @@
 #define ll_entry_start(_type, _list)					\
 ({									\
 	static char start[0] __aligned(CONFIG_LINKER_LIST_ALIGN)	\
-		__attribute__((unused,					\
-		section(".u_boot_list_2_"#_list"_1")));			\
+		__attribute__((unused))					\
+		__section(".u_boot_list_2_"#_list"_1");			\
 	(_type *)&start;						\
 })

@ -151,8 +151,8 @@
 */
 #define ll_entry_end(_type, _list)					\
 ({									\
-	static char end[0] __aligned(4) __attribute__((unused,		\
-		section(".u_boot_list_2_"#_list"_3")));			\
+	static char end[0] __aligned(4) __attribute__((unused))		\
+		__section(".u_boot_list_2_"#_list"_3");			\
 	(_type *)&end;							\
 })
 /**
@ -245,8 +245,8 @@
 */
 #define ll_start(_type)							\
 ({									\
-	static char start[0] __aligned(4) __attribute__((unused,	\
-		section(".u_boot_list_1")));				\
+	static char start[0] __aligned(4) __attribute__((unused))	\
+		__section(".u_boot_list_1");				\
 	(_type *)&start;						\
 })

@ -268,8 +268,8 @@
 */
 #define ll_end(_type)							\
 ({									\
-	static char end[0] __aligned(4) __attribute__((unused,		\
-		section(".u_boot_list_3")));				\
+	static char end[0] __aligned(4) __attribute__((unused))		\
+		__section(".u_boot_list_3");				\
 	(_type *)&end;							\
 })

--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@ -24,7 +24,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 			long ______r;					\
 			static struct ftrace_likely_data		\
 				__aligned(4)				\
-				__section(_ftrace_annotated_branch)	\
+				__section("_ftrace_annotated_branch")	\
 				______f = {				\
 				.data.func = __func__,			\
 				.data.file = __FILE__,			\
@ -60,7 +60,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 #define __trace_if_value(cond) ({			\
 	static struct ftrace_branch_data		\
 		__aligned(4)				\
-		__section(_ftrace_branch)		\
+		__section("_ftrace_branch")		\
 		__if_trace = {				\
 			.func = __func__,		\
 			.file = __FILE__,		\
@ -118,7 +118,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 	".popsection\n\t"

 /* Annotate a C jump table to allow objtool to follow the code flow */
-#define __annotate_jump_table __section(.rodata..c_jump_table)
+#define __annotate_jump_table __section(".rodata..c_jump_table")

 #else
 #define annotate_reachable()
@ -294,8 +294,8 @@ unsigned long read_word_at_a_time(const void *addr)
 * visible to the compiler.
 */
 #define __ADDRESSABLE(sym) \
-	static void * __section(.discard.addressable) __used \
-		__PASTE(__addressable_##sym, __LINE__) = (void *)&sym;
+	static void * __section(".discard.addressable") __used \
+		__UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)&sym;

 /**
 * offset_to_ptr - convert a relative memory offset to an absolute pointer
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@ -246,7 +246,7 @@
 *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-section-variable-attribute
 * clang: https://clang.llvm.org/docs/AttributeReference.html#section-declspec-allocate
 */
-#define __section(S)                    __attribute__((__section__(#S)))
+#define __section(S)                    __attribute__((__section__(S)))

 /*
 *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-unused-function-attribute
--- a/lib/crc32.c
+++ b/lib/crc32.c
@ -26,6 +26,7 @@
 #ifdef USE_HOSTCC
 #define __efi_runtime
 #define __efi_runtime_data
+#define __efi_runtime_rodata
 #endif

 #define tole(x) cpu_to_le32(x)
@ -88,7 +89,7 @@ static void __efi_runtime make_crc_table(void)
 * Table of CRC-32's of all single-byte values (made by make_crc_table)
 */

-static const uint32_t __efi_runtime_data crc_table[256] = {
+static const uint32_t __efi_runtime_rodata crc_table[256] = {
 tole(0x00000000L), tole(0x77073096L), tole(0xee0e612cL), tole(0x990951baL),
 tole(0x076dc419L), tole(0x706af48fL), tole(0xe963a535L), tole(0x9e6495a3L),
 tole(0x0edb8832L), tole(0x79dcb8a4L), tole(0xe0d5e91eL), tole(0x97d2d988L),
--- a/lib/efi_selftest/Makefile
+++ b/lib/efi_selftest/Makefile
@ -10,6 +10,8 @@ ccflags-y += -DHOST_ARCH="$(HOST_ARCH)"

 CFLAGS_dtbdump.o := $(CFLAGS_EFI) -Os -ffreestanding
 CFLAGS_REMOVE_dtbdump.o := $(CFLAGS_NON_EFI)
+CFLAGS_efi_selftest_miniapp_exception.o := $(CFLAGS_EFI) -Os -ffreestanding
+CFLAGS_REMOVE_efi_selftest_miniapp_exception.o := $(CFLAGS_NON_EFI)
 CFLAGS_efi_selftest_miniapp_exit.o := $(CFLAGS_EFI) -Os -ffreestanding
 CFLAGS_REMOVE_efi_selftest_miniapp_exit.o := $(CFLAGS_NON_EFI)
 CFLAGS_efi_selftest_miniapp_return.o := $(CFLAGS_EFI) -Os -ffreestanding
--- a/lib/errno.c
+++ b/lib/errno.c
@ -1 +1,3 @@
-int errno = 0;
+#include <errno.h>
+
+int errno __errno_asm_label = 0;
--- a/Show more
+++ b/Show more