kernel: use -ffunction-sections, -fdata-sections and --gc-sections on ARM to reduce kernel image size, disable those flags when tracing on MIPS to fix compile errors

SVN-Revision: 35936
master
Felix Fietkau 12 years ago
parent a1c2e78817
commit f0d7ba33ef
  1. 94
      target/linux/generic/patches-3.8/220-gc_sections.patch
  2. 2
      target/linux/generic/patches-3.8/305-mips_module_reloc.patch

@ -1,6 +1,6 @@
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -89,10 +89,12 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
@@ -89,10 +89,14 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
#
cflags-y += -G 0 -mno-abicalls -fno-pic -pipe
cflags-y += -msoft-float
@ -9,7 +9,9 @@
KBUILD_AFLAGS_MODULE += -mlong-calls
KBUILD_CFLAGS_MODULE += -mlong-calls
+ifndef CONFIG_FUNCTION_TRACER
+KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
+endif
+
cflags-y += -ffreestanding
@ -370,3 +372,93 @@
#else
#define INIT_RAM_FS
#endif
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -17,11 +17,16 @@ LDFLAGS_vmlinux :=-p --no-undefined -X
ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
LDFLAGS_vmlinux += --be8
endif
+LDFLAGS_vmlinux += --gc-sections
OBJCOPYFLAGS :=-O binary -R .comment -S
GZFLAGS :=-9
#KBUILD_CFLAGS +=-pipe
+ifndef CONFIG_FUNCTION_TRACER
+KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
+endif
+
# Never generate .eh_frame
KBUILD_CFLAGS += $(call cc-option,-fno-dwarf2-cfi-asm)
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -12,13 +12,13 @@
#define PROC_INFO \
. = ALIGN(4); \
VMLINUX_SYMBOL(__proc_info_begin) = .; \
- *(.proc.info.init) \
+ KEEP(*(.proc.info.init)) \
VMLINUX_SYMBOL(__proc_info_end) = .;
#define IDMAP_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__idmap_text_start) = .; \
- *(.idmap.text) \
+ KEEP(*(.idmap.text)) \
VMLINUX_SYMBOL(__idmap_text_end) = .;
#ifdef CONFIG_HOTPLUG_CPU
@@ -118,7 +118,7 @@ SECTIONS
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
__start___ex_table = .;
#ifdef CONFIG_MMU
- *(__ex_table)
+ KEEP(*(__ex_table))
#endif
__stop___ex_table = .;
}
@@ -130,12 +130,12 @@ SECTIONS
. = 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 = .;
}
#endif
@@ -158,24 +158,24 @@ 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 = .;
}
.init.data : {

@ -12,8 +12,8 @@
+KBUILD_CFLAGS_MODULE += -mno-long-calls
+endif
ifndef CONFIG_FUNCTION_TRACER
KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -11,6 +11,11 @@ struct mod_arch_specific {

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