openwrt/target/linux/generic/patches-3.8/220-gc_sections.patch
Felix Fietkau 8933b918cd kernel: use -ffunction-sections, -fdata-sections and --gc-sections on mips
in combination with kernel symbol export stripping this significantly reduces
the kernel image size

SVN-Revision: 35320
2013-01-26 16:26:13 +00:00

373 lines
12 KiB
Diff

--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -89,10 +89,12 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
#
cflags-y += -G 0 -mno-abicalls -fno-pic -pipe
cflags-y += -msoft-float
-LDFLAGS_vmlinux += -G 0 -static -n -nostdlib
+LDFLAGS_vmlinux += -G 0 -static -n -nostdlib --gc-sections
KBUILD_AFLAGS_MODULE += -mlong-calls
KBUILD_CFLAGS_MODULE += -mlong-calls
+KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
+
cflags-y += -ffreestanding
#
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -67,7 +67,7 @@ SECTIONS
/* Exception table for data bus errors */
__dbe_table : {
__start___dbe_table = .;
- *(__dbe_table)
+ KEEP(*(__dbe_table))
__stop___dbe_table = .;
}
@@ -112,7 +112,7 @@ 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 = .;
}
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -101,7 +101,7 @@
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
#define MCOUNT_REC() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_mcount_loc) = .; \
- *(__mcount_loc) \
+ KEEP(*(__mcount_loc)) \
VMLINUX_SYMBOL(__stop_mcount_loc) = .;
#else
#define MCOUNT_REC()
@@ -109,7 +109,7 @@
#ifdef CONFIG_TRACE_BRANCH_PROFILING
#define LIKELY_PROFILE() VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
- *(_ftrace_annotated_branch) \
+ KEEP(*(_ftrace_annotated_branch)) \
VMLINUX_SYMBOL(__stop_annotated_branch_profile) = .;
#else
#define LIKELY_PROFILE()
@@ -117,7 +117,7 @@
#ifdef CONFIG_PROFILE_ALL_BRANCHES
#define BRANCH_PROFILE() VMLINUX_SYMBOL(__start_branch_profile) = .; \
- *(_ftrace_branch) \
+ KEEP(*(_ftrace_branch)) \
VMLINUX_SYMBOL(__stop_branch_profile) = .;
#else
#define BRANCH_PROFILE()
@@ -126,7 +126,7 @@
#ifdef CONFIG_EVENT_TRACING
#define FTRACE_EVENTS() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_ftrace_events) = .; \
- *(_ftrace_events) \
+ KEEP(*(_ftrace_events)) \
VMLINUX_SYMBOL(__stop_ftrace_events) = .;
#else
#define FTRACE_EVENTS()
@@ -134,7 +134,7 @@
#ifdef CONFIG_TRACING
#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \
- *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
+ KEEP(*(__trace_printk_fmt)) /* Trace_printk fmt' pointer */ \
VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
#else
#define TRACE_PRINTKS()
@@ -143,7 +143,7 @@
#ifdef CONFIG_FTRACE_SYSCALLS
#define TRACE_SYSCALLS() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
- *(__syscalls_metadata) \
+ KEEP(*(__syscalls_metadata)) \
VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
#else
#define TRACE_SYSCALLS()
@@ -153,7 +153,7 @@
#define KERNEL_DTB() \
STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__dtb_start) = .; \
- *(.dtb.init.rodata) \
+ KEEP(*(.dtb.init.rodata)) \
VMLINUX_SYMBOL(__dtb_end) = .;
/* .data section */
@@ -173,15 +173,16 @@
/* implement dynamic printk debug */ \
. = ALIGN(8); \
VMLINUX_SYMBOL(__start___jump_table) = .; \
- *(__jump_table) \
+ KEEP(*(__jump_table)) \
VMLINUX_SYMBOL(__stop___jump_table) = .; \
. = ALIGN(8); \
VMLINUX_SYMBOL(__start___verbose) = .; \
- *(__verbose) \
+ KEEP(*(__verbose)) \
VMLINUX_SYMBOL(__stop___verbose) = .; \
LIKELY_PROFILE() \
BRANCH_PROFILE() \
- TRACE_PRINTKS()
+ TRACE_PRINTKS() \
+ *(.data.*)
/*
* Data section helpers
@@ -235,39 +236,39 @@
/* PCI quirks */ \
.pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_pci_fixups_early) = .; \
- *(.pci_fixup_early) \
+ KEEP(*(.pci_fixup_early)) \
VMLINUX_SYMBOL(__end_pci_fixups_early) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_header) = .; \
- *(.pci_fixup_header) \
+ KEEP(*(.pci_fixup_header)) \
VMLINUX_SYMBOL(__end_pci_fixups_header) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_final) = .; \
- *(.pci_fixup_final) \
+ KEEP(*(.pci_fixup_final)) \
VMLINUX_SYMBOL(__end_pci_fixups_final) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_enable) = .; \
- *(.pci_fixup_enable) \
+ KEEP(*(.pci_fixup_enable)) \
VMLINUX_SYMBOL(__end_pci_fixups_enable) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_resume) = .; \
- *(.pci_fixup_resume) \
+ KEEP(*(.pci_fixup_resume)) \
VMLINUX_SYMBOL(__end_pci_fixups_resume) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .; \
- *(.pci_fixup_resume_early) \
+ KEEP(*(.pci_fixup_resume_early)) \
VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .; \
- *(.pci_fixup_suspend) \
+ KEEP(*(.pci_fixup_suspend)) \
VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .; \
} \
\
/* Built-in firmware blobs */ \
.builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_builtin_fw) = .; \
- *(.builtin_fw) \
+ KEEP(*(.builtin_fw)) \
VMLINUX_SYMBOL(__end_builtin_fw) = .; \
} \
\
/* RapidIO route ops */ \
.rio_ops : AT(ADDR(.rio_ops) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_rio_switch_ops) = .; \
- *(.rio_switch_ops) \
+ KEEP(*(.rio_switch_ops)) \
VMLINUX_SYMBOL(__end_rio_switch_ops) = .; \
} \
\
@@ -276,49 +277,49 @@
/* Kernel symbol table: Normal symbols */ \
__ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab) = .; \
- *(SORT(___ksymtab+*)) \
+ KEEP(*(SORT(___ksymtab+*))) \
VMLINUX_SYMBOL(__stop___ksymtab) = .; \
} \
\
/* Kernel symbol table: GPL-only symbols */ \
__ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_gpl) = .; \
- *(SORT(___ksymtab_gpl+*)) \
+ KEEP(*(SORT(___ksymtab_gpl+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \
} \
\
/* Kernel symbol table: Normal unused symbols */ \
__ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \
- *(SORT(___ksymtab_unused+*)) \
+ KEEP(*(SORT(___ksymtab_unused+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \
} \
\
/* Kernel symbol table: GPL-only unused symbols */ \
__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \
- *(SORT(___ksymtab_unused_gpl+*)) \
+ KEEP(*(SORT(___ksymtab_unused_gpl+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \
} \
\
/* Kernel symbol table: GPL-future-only symbols */ \
__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \
- *(SORT(___ksymtab_gpl_future+*)) \
+ KEEP(*(SORT(___ksymtab_gpl_future+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .; \
} \
\
/* Kernel symbol table: Normal symbols */ \
__kcrctab : AT(ADDR(__kcrctab) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab) = .; \
- *(SORT(___kcrctab+*)) \
+ KEEP(*(SORT(___kcrctab+*))) \
VMLINUX_SYMBOL(__stop___kcrctab) = .; \
} \
\
/* Kernel symbol table: GPL-only symbols */ \
__kcrctab_gpl : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_gpl) = .; \
- *(SORT(___kcrctab_gpl+*)) \
+ KEEP(*(SORT(___kcrctab_gpl+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .; \
} \
\
@@ -332,14 +333,14 @@
/* Kernel symbol table: GPL-only unused symbols */ \
__kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .; \
- *(SORT(___kcrctab_unused_gpl+*)) \
+ KEEP(*(SORT(___kcrctab_unused_gpl+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .; \
} \
\
/* Kernel symbol table: GPL-future-only symbols */ \
__kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .; \
- *(SORT(___kcrctab_gpl_future+*)) \
+ KEEP(*(SORT(___kcrctab_gpl_future+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .; \
} \
\
@@ -362,14 +363,14 @@
/* Built-in module parameters. */ \
__param : AT(ADDR(__param) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___param) = .; \
- *(__param) \
+ KEEP(*(__param)) \
VMLINUX_SYMBOL(__stop___param) = .; \
} \
\
/* Built-in module versions. */ \
__modver : AT(ADDR(__modver) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___modver) = .; \
- *(__modver) \
+ KEEP(*(__modver)) \
VMLINUX_SYMBOL(__stop___modver) = .; \
. = ALIGN((align)); \
VMLINUX_SYMBOL(__end_rodata) = .; \
@@ -429,7 +430,7 @@
#define ENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__entry_text_start) = .; \
- *(.entry.text) \
+ KEEP(*(.entry.text)) \
VMLINUX_SYMBOL(__entry_text_end) = .;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -457,7 +458,7 @@
. = ALIGN(align); \
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ex_table) = .; \
- *(__ex_table) \
+ KEEP(*(__ex_table)) \
VMLINUX_SYMBOL(__stop___ex_table) = .; \
}
@@ -473,7 +474,7 @@
#ifdef CONFIG_CONSTRUCTORS
#define KERNEL_CTORS() . = ALIGN(8); \
VMLINUX_SYMBOL(__ctors_start) = .; \
- *(.ctors) \
+ KEEP(*(.ctors)) \
VMLINUX_SYMBOL(__ctors_end) = .;
#else
#define KERNEL_CTORS()
@@ -526,7 +527,7 @@
#define SBSS(sbss_align) \
. = ALIGN(sbss_align); \
.sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \
- *(.sbss) \
+ *(.sbss .sbss.*) \
*(.scommon) \
}
@@ -544,7 +545,7 @@
BSS_FIRST_SECTIONS \
*(.bss..page_aligned) \
*(.dynbss) \
- *(.bss) \
+ *(.bss .bss.*) \
*(COMMON) \
}
@@ -593,7 +594,7 @@
. = ALIGN(8); \
__bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___bug_table) = .; \
- *(__bug_table) \
+ KEEP(*(__bug_table)) \
VMLINUX_SYMBOL(__stop___bug_table) = .; \
}
#else
@@ -605,7 +606,7 @@
. = ALIGN(4); \
.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__tracedata_start) = .; \
- *(.tracedata) \
+ KEEP(*(.tracedata)) \
VMLINUX_SYMBOL(__tracedata_end) = .; \
}
#else
@@ -622,17 +623,17 @@
#define INIT_SETUP(initsetup_align) \
. = ALIGN(initsetup_align); \
VMLINUX_SYMBOL(__setup_start) = .; \
- *(.init.setup) \
+ KEEP(*(.init.setup)) \
VMLINUX_SYMBOL(__setup_end) = .;
#define INIT_CALLS_LEVEL(level) \
VMLINUX_SYMBOL(__initcall##level##_start) = .; \
- *(.initcall##level##.init) \
- *(.initcall##level##s.init) \
+ KEEP(*(.initcall##level##.init)) \
+ KEEP(*(.initcall##level##s.init)) \
#define INIT_CALLS \
VMLINUX_SYMBOL(__initcall_start) = .; \
- *(.initcallearly.init) \
+ KEEP(*(.initcallearly.init)) \
INIT_CALLS_LEVEL(0) \
INIT_CALLS_LEVEL(1) \
INIT_CALLS_LEVEL(2) \
@@ -646,21 +647,21 @@
#define CON_INITCALL \
VMLINUX_SYMBOL(__con_initcall_start) = .; \
- *(.con_initcall.init) \
+ KEEP(*(.con_initcall.init)) \
VMLINUX_SYMBOL(__con_initcall_end) = .;
#define SECURITY_INITCALL \
VMLINUX_SYMBOL(__security_initcall_start) = .; \
- *(.security_initcall.init) \
+ KEEP(*(.security_initcall.init)) \
VMLINUX_SYMBOL(__security_initcall_end) = .;
#ifdef CONFIG_BLK_DEV_INITRD
#define INIT_RAM_FS \
. = ALIGN(4); \
VMLINUX_SYMBOL(__initramfs_start) = .; \
- *(.init.ramfs) \
+ KEEP(*(.init.ramfs)) \
. = ALIGN(8); \
- *(.init.ramfs.info)
+ KEEP(*(.init.ramfs.info))
#else
#define INIT_RAM_FS
#endif