+++ /dev/null
-From e3d8676f5722b7622685581e06e8f53e6138e3ab Mon Sep 17 00:00:00 2001
-From: Felix Fietkau <nbd@nbd.name>
-Date: Sat, 15 Jul 2017 23:42:36 +0200
-Subject: use -ffunction-sections, -fdata-sections and --gc-sections
-
-In combination with kernel symbol export stripping this significantly reduces
-the kernel image size. Used on both ARM and MIPS architectures.
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
-Signed-off-by: Jonas Gorski <jogo@openwrt.org>
-Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
----
- Makefile | 10 +++----
- arch/arm/Kconfig | 1 +
- arch/arm/boot/compressed/Makefile | 1 +
- arch/arm/kernel/vmlinux.lds.S | 26 ++++++++--------
- arch/mips/Kconfig | 1 +
- arch/mips/kernel/vmlinux.lds.S | 4 +--
- include/asm-generic/vmlinux.lds.h | 63 ++++++++++++++++++++-------------------
- 7 files changed, 55 insertions(+), 51 deletions(-)
-
---- a/Makefile
-+++ b/Makefile
-@@ -294,6 +294,11 @@ else
- scripts/Kbuild.include: ;
- include scripts/Kbuild.include
-
-+ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
-+KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
-+LDFLAGS_vmlinux += --gc-sections
-+endif
-+
- # Read KERNELRELEASE from include/config/kernel.release (if it exists)
- KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
- KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
-@@ -772,11 +777,6 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
- KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
- endif
-
--ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
--KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
--LDFLAGS_vmlinux += --gc-sections
--endif
--
- # arch Makefile may override CC so keep this after arch Makefile is included
- NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
-
---- a/arch/arm/Kconfig
-+++ b/arch/arm/Kconfig
-@@ -98,6 +98,7 @@ config ARM
- select HAVE_UID16
- select HAVE_VIRT_CPU_ACCOUNTING_GEN
- select IRQ_FORCED_THREADING
-+ select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
- select MODULES_USE_ELF_REL
- select NEED_DMA_MAP_STATE
- select NO_BOOTMEM
---- a/arch/arm/boot/compressed/Makefile
-+++ b/arch/arm/boot/compressed/Makefile
-@@ -106,6 +106,7 @@ ifeq ($(CONFIG_FUNCTION_TRACER),y)
- ORIG_CFLAGS := $(KBUILD_CFLAGS)
- KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
- endif
-+KBUILD_CFLAGS_KERNEL := $(patsubst -f%-sections,,$(KBUILD_CFLAGS_KERNEL))
-
- # -fstack-protector-strong triggers protection checks in this code,
- # but it is being used too early to link to meaningful stack_chk logic.
---- a/arch/arm/kernel/vmlinux.lds.S
-+++ b/arch/arm/kernel/vmlinux.lds.S
-@@ -100,24 +100,24 @@ SECTIONS
- }
- .init.arch.info : {
- __arch_info_begin = .;
-- *(.arch.info.init)
-+ KEEP(*(.arch.info.init))
- __arch_info_end = .;
- }
- .init.tagtable : {
- __tagtable_begin = .;
-- *(.taglist.init)
-+ KEEP(*(.taglist.init))
- __tagtable_end = .;
- }
- #ifdef CONFIG_SMP_ON_UP
- .init.smpalt : {
- __smpalt_begin = .;
-- *(.alt.smp.init)
-+ KEEP(*(.alt.smp.init))
- __smpalt_end = .;
- }
- #endif
- .init.pv_table : {
- __pv_table_begin = .;
-- *(.pv_table)
-+ KEEP(*(.pv_table))
- __pv_table_end = .;
- }
-
---- a/arch/arm/kernel/vmlinux.lds.h
-+++ b/arch/arm/kernel/vmlinux.lds.h
-@@ -22,13 +22,13 @@
- #define ARM_MMU_DISCARD(x)
- #else
- #define ARM_MMU_KEEP(x)
--#define ARM_MMU_DISCARD(x) x
-+#define ARM_MMU_DISCARD(x) KEEP(x)
- #endif
-
- #define PROC_INFO \
- . = ALIGN(4); \
- __proc_info_begin = .; \
-- *(.proc.info.init) \
-+ KEEP(*(.proc.info.init)) \
- __proc_info_end = .;
-
- #define HYPERVISOR_TEXT \
-@@ -39,11 +39,11 @@
- #define IDMAP_TEXT \
- ALIGN_FUNCTION(); \
- __idmap_text_start = .; \
-- *(.idmap.text) \
-+ KEEP(*(.idmap.text)) \
- __idmap_text_end = .; \
- . = ALIGN(PAGE_SIZE); \
- __hyp_idmap_text_start = .; \
-- *(.hyp.idmap.text) \
-+ KEEP(*(.hyp.idmap.text)) \
- __hyp_idmap_text_end = .;
-
- #define ARM_DISCARD \
-@@ -86,12 +86,12 @@
- . = ALIGN(8); \
- .ARM.unwind_idx : { \
- __start_unwind_idx = .; \
-- *(.ARM.exidx*) \
-+ KEEP(*(.ARM.exidx*)) \
- __stop_unwind_idx = .; \
- } \
- .ARM.unwind_tab : { \
- __start_unwind_tab = .; \
-- *(.ARM.extab*) \
-+ KEEP(*(.ARM.extab*)) \
- __stop_unwind_tab = .; \
- }
-
-@@ -102,14 +102,14 @@
- #define ARM_VECTORS \
- __vectors_start = .; \
- .vectors 0xffff0000 : AT(__vectors_start) { \
-- *(.vectors) \
-+ KEEP(*(.vectors)) \
- } \
- . = __vectors_start + SIZEOF(.vectors); \
- __vectors_end = .; \
- \
- __stubs_start = .; \
- .stubs ADDR(.vectors) + 0x1000 : AT(__stubs_start) { \
-- *(.stubs) \
-+ KEEP(*(.stubs)) \
- } \
- . = __stubs_start + SIZEOF(.stubs); \
- __stubs_end = .; \
---- a/arch/mips/Kconfig
-+++ b/arch/mips/Kconfig
-@@ -43,6 +43,7 @@ config MIPS
- select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES && 64BIT
- select HAVE_CBPF_JIT if (!64BIT && !CPU_MICROMIPS)
- select HAVE_EBPF_JIT if (64BIT && !CPU_MICROMIPS)
-+ select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
- select HAVE_CONTEXT_TRACKING
- select HAVE_COPY_THREAD_TLS
- select HAVE_C_RECORDMCOUNT
---- a/arch/mips/kernel/vmlinux.lds.S
-+++ b/arch/mips/kernel/vmlinux.lds.S
-@@ -72,7 +72,7 @@ SECTIONS
- /* Exception table for data bus errors */
- __dbe_table : {
- __start___dbe_table = .;
-- *(__dbe_table)
-+ KEEP(*(__dbe_table))
- __stop___dbe_table = .;
- }
-
-@@ -123,7 +123,7 @@ SECTIONS
- . = ALIGN(4);
- .mips.machines.init : AT(ADDR(.mips.machines.init) - LOAD_OFFSET) {
- __mips_machines_start = .;
-- *(.mips.machines.init)
-+ KEEP(*(.mips.machines.init))
- __mips_machines_end = .;
- }
-
projects / openwrt / staging / dedeckeh.git / blobdiff