Initial commit

target/linux/generic/hack-5.4/220-arm-gc_sections.patch

@@ -0,0 +1,138 @@
+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/arch/arm/Kconfig
++++ b/arch/arm/Kconfig
+@@ -111,6 +111,7 @@ 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 OF_EARLY_FLATTREE if OF
+--- a/arch/arm/boot/compressed/Makefile
++++ b/arch/arm/boot/compressed/Makefile
+@@ -108,6 +108,7 @@ 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
+@@ -73,7 +73,7 @@ SECTIONS
+ 	. = ALIGN(4);
+ 	__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
+ 		__start___ex_table = .;
+-		ARM_MMU_KEEP(*(__ex_table))
++		KEEP(*(__ex_table))
+ 		__stop___ex_table = .;
+ 	}
+ 
+@@ -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
+@@ -28,7 +28,7 @@
+ #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 = .;						\