lede/target/linux/generic/hack-6.12/220-arm-gc_sections.patch
2025-04-12 11:20:54 +08:00

95 lines
2.6 KiB
Diff

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>
---
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -136,6 +136,7 @@ config ARM
select HAVE_VIRT_CPU_ACCOUNTING_GEN
select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
select IRQ_FORCED_THREADING
+ select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_REL
select NEED_DMA_MAP_STATE
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -86,6 +86,7 @@ endif
ifeq ($(CONFIG_USE_OF),y)
OBJS += $(libfdt_objs) fdt_check_mem_start.o
endif
+KBUILD_CFLAGS_KERNEL := $(patsubst -f%-sections,,$(KBUILD_CFLAGS_KERNEL))
OBJS += lib1funcs.o ashldi3.o bswapsdi2.o
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -74,7 +74,7 @@ SECTIONS
. = ALIGN(4);
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
__start___ex_table = .;
- ARM_MMU_KEEP(KEEP(*(__ex_table)))
+ KEEP(*(__ex_table))
__stop___ex_table = .;
}
@@ -104,13 +104,13 @@ SECTIONS
}
.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
--- a/arch/arm/include/asm/vmlinux.lds.h
+++ b/arch/arm/include/asm/vmlinux.lds.h
@@ -48,7 +48,7 @@
#define IDMAP_TEXT \
ALIGN_FUNCTION(); \
__idmap_text_start = .; \
- *(.idmap.text) \
+ KEEP(*(.idmap.text)) \
__idmap_text_end = .; \
#define ARM_DISCARD \
@@ -108,12 +108,12 @@
. = 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 = .; \
}
@@ -143,7 +143,7 @@
\
__stubs_lma = .; \
.stubs ADDR(.vectors) + 0x1000 : AT(__stubs_lma) { \
- *(.stubs) \
+ KEEP(*(.stubs)) \
} \
ARM_LMA(__stubs, .stubs); \
. = __stubs_lma + SIZEOF(.stubs); \