diff options
Diffstat (limited to 'include/asm-generic/vmlinux.lds.h')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 350 |
1 files changed, 325 insertions, 25 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c61fab1dd2f..6ad76bf5fb4 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -1,3 +1,56 @@ +/* + * Helper macros to support writing architecture specific + * linker scripts. + * + * A minimal linker scripts has following content: + * [This is a sample, architectures may have special requiriements] + * + * OUTPUT_FORMAT(...) + * OUTPUT_ARCH(...) + * ENTRY(...) + * SECTIONS + * { + * . = START; + * __init_begin = .; + * HEAD_TEXT_SECTION + * INIT_TEXT_SECTION(PAGE_SIZE) + * INIT_DATA_SECTION(...) + * PERCPU(PAGE_SIZE) + * __init_end = .; + * + * _stext = .; + * TEXT_SECTION = 0 + * _etext = .; + * + * _sdata = .; + * RO_DATA_SECTION(PAGE_SIZE) + * RW_DATA_SECTION(...) + * _edata = .; + * + * EXCEPTION_TABLE(...) + * NOTES + * + * BSS_SECTION(0, 0, 0) + * _end = .; + * + * /DISCARD/ : { + * EXIT_TEXT + * EXIT_DATA + * EXIT_CALL + * } + * STABS_DEBUG + * DWARF_DEBUG + * } + * + * [__init_begin, __init_end] is the init section that may be freed after init + * [_stext, _etext] is the text section + * [_sdata, _edata] is the data section + * + * Some of the included output section have their own set of constants. + * Examples are: [__initramfs_start, __initramfs_end] for initramfs and + * [__nosave_begin, __nosave_end] for the nosave data + */ + #ifndef LOAD_OFFSET #define LOAD_OFFSET 0 #endif @@ -61,10 +114,33 @@ #define BRANCH_PROFILE() #endif +#ifdef CONFIG_EVENT_TRACING +#define FTRACE_EVENTS() VMLINUX_SYMBOL(__start_ftrace_events) = .; \ + *(_ftrace_events) \ + VMLINUX_SYMBOL(__stop_ftrace_events) = .; +#else +#define FTRACE_EVENTS() +#endif + +#ifdef CONFIG_TRACING +#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \ + *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \ + VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .; +#else +#define TRACE_PRINTKS() +#endif + +#ifdef CONFIG_FTRACE_SYSCALLS +#define TRACE_SYSCALLS() VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \ + *(__syscalls_metadata) \ + VMLINUX_SYMBOL(__stop_syscalls_metadata) = .; +#else +#define TRACE_SYSCALLS() +#endif + /* .data section */ #define DATA_DATA \ *(.data) \ - *(.data.init.refok) \ *(.ref.data) \ DEV_KEEP(init.data) \ DEV_KEEP(exit.data) \ @@ -80,10 +156,47 @@ VMLINUX_SYMBOL(__start___tracepoints) = .; \ *(__tracepoints) \ VMLINUX_SYMBOL(__stop___tracepoints) = .; \ + /* implement dynamic printk debug */ \ + . = ALIGN(8); \ + VMLINUX_SYMBOL(__start___verbose) = .; \ + *(__verbose) \ + VMLINUX_SYMBOL(__stop___verbose) = .; \ LIKELY_PROFILE() \ - BRANCH_PROFILE() + BRANCH_PROFILE() \ + TRACE_PRINTKS() \ + FTRACE_EVENTS() \ + TRACE_SYSCALLS() + +/* + * Data section helpers + */ +#define NOSAVE_DATA \ + . = ALIGN(PAGE_SIZE); \ + VMLINUX_SYMBOL(__nosave_begin) = .; \ + *(.data.nosave) \ + . = ALIGN(PAGE_SIZE); \ + VMLINUX_SYMBOL(__nosave_end) = .; + +#define PAGE_ALIGNED_DATA(page_align) \ + . = ALIGN(page_align); \ + *(.data.page_aligned) + +#define READ_MOSTLY_DATA(align) \ + . = ALIGN(align); \ + *(.data.read_mostly) -#define RO_DATA(align) \ +#define CACHELINE_ALIGNED_DATA(align) \ + . = ALIGN(align); \ + *(.data.cacheline_aligned) + +#define INIT_TASK_DATA(align) \ + . = ALIGN(align); \ + *(.data.init_task) + +/* + * Read only Data + */ +#define RO_DATA_SECTION(align) \ . = ALIGN((align)); \ .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__start_rodata) = .; \ @@ -237,9 +350,10 @@ } \ . = ALIGN((align)); -/* RODATA provided for backward compatibility. +/* RODATA & RO_DATA provided for backward compatibility. * All archs are supposed to use RO_DATA() */ -#define RODATA RO_DATA(4096) +#define RODATA RO_DATA_SECTION(4096) +#define RO_DATA(align) RO_DATA_SECTION(align) #define SECURITY_INIT \ .security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \ @@ -255,8 +369,6 @@ *(.text.hot) \ *(.text) \ *(.ref.text) \ - *(.text.init.refok) \ - *(.exit.text.refok) \ DEV_KEEP(init.text) \ DEV_KEEP(exit.text) \ CPU_KEEP(init.text) \ @@ -301,23 +413,51 @@ /* Section used for early init (in .S files) */ #define HEAD_TEXT *(.head.text) +#define HEAD_TEXT_SECTION \ + .head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { \ + HEAD_TEXT \ + } + +/* + * Exception table + */ +#define EXCEPTION_TABLE(align) \ + . = ALIGN(align); \ + __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__start___ex_table) = .; \ + *(__ex_table) \ + VMLINUX_SYMBOL(__stop___ex_table) = .; \ + } + +/* + * Init task + */ +#define INIT_TASK_DATA_SECTION(align) \ + . = ALIGN(align); \ + .data.init_task : { \ + INIT_TASK_DATA(align) \ + } + +#ifdef CONFIG_CONSTRUCTORS +#define KERNEL_CTORS() . = ALIGN(8); \ + VMLINUX_SYMBOL(__ctors_start) = .; \ + *(.ctors) \ + VMLINUX_SYMBOL(__ctors_end) = .; +#else +#define KERNEL_CTORS() +#endif + /* init and exit section handling */ #define INIT_DATA \ *(.init.data) \ DEV_DISCARD(init.data) \ - DEV_DISCARD(init.rodata) \ CPU_DISCARD(init.data) \ - CPU_DISCARD(init.rodata) \ MEM_DISCARD(init.data) \ - MEM_DISCARD(init.rodata) \ - /* implement dynamic printk debug */ \ - VMLINUX_SYMBOL(__start___verbose_strings) = .; \ - *(__verbose_strings) \ - VMLINUX_SYMBOL(__stop___verbose_strings) = .; \ - . = ALIGN(8); \ - VMLINUX_SYMBOL(__start___verbose) = .; \ - *(__verbose) \ - VMLINUX_SYMBOL(__stop___verbose) = .; + KERNEL_CTORS() \ + *(.init.rodata) \ + DEV_DISCARD(init.rodata) \ + CPU_DISCARD(init.rodata) \ + MEM_DISCARD(init.rodata) #define INIT_TEXT \ *(.init.text) \ @@ -340,9 +480,34 @@ CPU_DISCARD(exit.text) \ MEM_DISCARD(exit.text) - /* DWARF debug sections. - Symbols in the DWARF debugging sections are relative to - the beginning of the section so we begin them at 0. */ +#define EXIT_CALL \ + *(.exitcall.exit) + +/* + * bss (Block Started by Symbol) - uninitialized data + * zeroed during startup + */ +#define SBSS(sbss_align) \ + . = ALIGN(sbss_align); \ + .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \ + *(.sbss) \ + *(.scommon) \ + } + +#define BSS(bss_align) \ + . = ALIGN(bss_align); \ + .bss : AT(ADDR(.bss) - LOAD_OFFSET) { \ + *(.bss.page_aligned) \ + *(.dynbss) \ + *(.bss) \ + *(COMMON) \ + } + +/* + * DWARF debug sections. + * Symbols in the DWARF debugging sections are relative to + * the beginning of the section so we begin them at 0. + */ #define DWARF_DEBUG \ /* DWARF 1 */ \ .debug 0 : { *(.debug) } \ @@ -409,6 +574,12 @@ VMLINUX_SYMBOL(__stop_notes) = .; \ } +#define INIT_SETUP(initsetup_align) \ + . = ALIGN(initsetup_align); \ + VMLINUX_SYMBOL(__setup_start) = .; \ + *(.init.setup) \ + VMLINUX_SYMBOL(__setup_end) = .; + #define INITCALLS \ *(.initcallearly.init) \ VMLINUX_SYMBOL(__early_initcall_end) = .; \ @@ -430,12 +601,141 @@ *(.initcall7.init) \ *(.initcall7s.init) +#define INIT_CALLS \ + VMLINUX_SYMBOL(__initcall_start) = .; \ + INITCALLS \ + VMLINUX_SYMBOL(__initcall_end) = .; + +#define CON_INITCALL \ + VMLINUX_SYMBOL(__con_initcall_start) = .; \ + *(.con_initcall.init) \ + VMLINUX_SYMBOL(__con_initcall_end) = .; + +#define SECURITY_INITCALL \ + VMLINUX_SYMBOL(__security_initcall_start) = .; \ + *(.security_initcall.init) \ + VMLINUX_SYMBOL(__security_initcall_end) = .; + +#ifdef CONFIG_BLK_DEV_INITRD +#define INIT_RAM_FS \ + . = ALIGN(PAGE_SIZE); \ + VMLINUX_SYMBOL(__initramfs_start) = .; \ + *(.init.ramfs) \ + VMLINUX_SYMBOL(__initramfs_end) = .; +#else +#define INIT_RAM_FS +#endif + +/** + * PERCPU_VADDR - define output section for percpu area + * @vaddr: explicit base address (optional) + * @phdr: destination PHDR (optional) + * + * Macro which expands to output section for percpu area. If @vaddr + * is not blank, it specifies explicit base address and all percpu + * symbols will be offset from the given address. If blank, @vaddr + * always equals @laddr + LOAD_OFFSET. + * + * @phdr defines the output PHDR to use if not blank. Be warned that + * output PHDR is sticky. If @phdr is specified, the next output + * section in the linker script will go there too. @phdr should have + * a leading colon. + * + * Note that this macros defines __per_cpu_load as an absolute symbol. + * If there is no need to put the percpu section at a predetermined + * address, use PERCPU(). + */ +#define PERCPU_VADDR(vaddr, phdr) \ + VMLINUX_SYMBOL(__per_cpu_load) = .; \ + .data.percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load) \ + - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__per_cpu_start) = .; \ + *(.data.percpu.first) \ + *(.data.percpu.page_aligned) \ + *(.data.percpu) \ + *(.data.percpu.shared_aligned) \ + VMLINUX_SYMBOL(__per_cpu_end) = .; \ + } phdr \ + . = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data.percpu); + +/** + * PERCPU - define output section for percpu area, simple version + * @align: required alignment + * + * Align to @align and outputs output section for percpu area. This + * macro doesn't maniuplate @vaddr or @phdr and __per_cpu_load and + * __per_cpu_start will be identical. + * + * This macro is equivalent to ALIGN(align); PERCPU_VADDR( , ) except + * that __per_cpu_load is defined as a relative symbol against + * .data.percpu which is required for relocatable x86_32 + * configuration. + */ #define PERCPU(align) \ . = ALIGN(align); \ - VMLINUX_SYMBOL(__per_cpu_start) = .; \ - .data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { \ + .data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__per_cpu_load) = .; \ + VMLINUX_SYMBOL(__per_cpu_start) = .; \ + *(.data.percpu.first) \ *(.data.percpu.page_aligned) \ *(.data.percpu) \ *(.data.percpu.shared_aligned) \ - } \ - VMLINUX_SYMBOL(__per_cpu_end) = .; + VMLINUX_SYMBOL(__per_cpu_end) = .; \ + } + + +/* + * Definition of the high level *_SECTION macros + * They will fit only a subset of the architectures + */ + + +/* + * Writeable data. + * All sections are combined in a single .data section. + * The sections following CONSTRUCTORS are arranged so their + * typical alignment matches. + * A cacheline is typical/always less than a PAGE_SIZE so + * the sections that has this restriction (or similar) + * is located before the ones requiring PAGE_SIZE alignment. + * NOSAVE_DATA starts and ends with a PAGE_SIZE alignment which + * matches the requirment of PAGE_ALIGNED_DATA. + * + * use 0 as page_align if page_aligned data is not used */ +#define RW_DATA_SECTION(cacheline, pagealigned, inittask) \ + . = ALIGN(PAGE_SIZE); \ + .data : AT(ADDR(.data) - LOAD_OFFSET) { \ + INIT_TASK_DATA(inittask) \ + CACHELINE_ALIGNED_DATA(cacheline) \ + READ_MOSTLY_DATA(cacheline) \ + DATA_DATA \ + CONSTRUCTORS \ + NOSAVE_DATA \ + PAGE_ALIGNED_DATA(pagealigned) \ + } + +#define INIT_TEXT_SECTION(inittext_align) \ + . = ALIGN(inittext_align); \ + .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(_sinittext) = .; \ + INIT_TEXT \ + VMLINUX_SYMBOL(_einittext) = .; \ + } + +#define INIT_DATA_SECTION(initsetup_align) \ + .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { \ + INIT_DATA \ + INIT_SETUP(initsetup_align) \ + INIT_CALLS \ + CON_INITCALL \ + SECURITY_INITCALL \ + INIT_RAM_FS \ + } + +#define BSS_SECTION(sbss_align, bss_align, stop_align) \ + . = ALIGN(sbss_align); \ + VMLINUX_SYMBOL(__bss_start) = .; \ + SBSS(sbss_align) \ + BSS(bss_align) \ + . = ALIGN(stop_align); \ + VMLINUX_SYMBOL(__bss_stop) = .; |