linux/arch/powerpc/kernel/vmlinux.lds.S

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#ifdef CONFIG_PPC64
#define PROVIDE32(x) PROVIDE(__unused__##x)
#else
#define PROVIDE32(x) PROVIDE(x)
#endif
#include <asm/page.h>
#include <asm-generic/vmlinux.lds.h>
#include <asm/cache.h>
ENTRY(_stext)
PHDRS {
kernel PT_LOAD FLAGS(7); /* RWX */
notes PT_NOTE FLAGS(0);
dummy PT_NOTE FLAGS(0);
/* binutils < 2.18 has a bug that makes it misbehave when taking an
ELF file with all segments at load address 0 as input. This
happens when running "strip" on vmlinux, because of the AT() magic
in this linker script. People using GCC >= 4.2 won't run into
this problem, because the "build-id" support will put some data
into the "notes" segment (at a non-zero load address).
To work around this, we force some data into both the "dummy"
segment and the kernel segment, so the dummy segment will get a
non-zero load address. It's not enough to always create the
"notes" segment, since if nothing gets assigned to it, its load
address will be zero. */
}
#ifdef CONFIG_PPC64
OUTPUT_ARCH(powerpc:common64)
jiffies = jiffies_64;
#else
OUTPUT_ARCH(powerpc:common)
jiffies = jiffies_64 + 4;
#endif
SECTIONS
{
/* Sections to be discarded. */
/DISCARD/ : {
*(.exitcall.exit)
EXIT_DATA
}
. = KERNELBASE;
/*
* Text, read only data and other permanent read-only sections
*/
/* Text and gots */
.text : AT(ADDR(.text) - LOAD_OFFSET) {
ALIGN_FUNCTION();
*(.text.head)
_text = .;
powerpc: Introduce infrastructure for feature sections with alternatives The current feature section logic only supports nop'ing out code, this means if you want to choose at runtime between instruction sequences, one or both cases will have to execute the nop'ed out contents of the other section, eg: BEGIN_FTR_SECTION or 1,1,1 END_FTR_SECTION_IFSET(FOO) BEGIN_FTR_SECTION or 2,2,2 END_FTR_SECTION_IFCLR(FOO) and the resulting code will be either, or 1,1,1 nop or, nop or 2,2,2 For small code segments this is fine, but for larger code blocks and in performance criticial code segments, it would be nice to avoid the nops. This commit starts to implement logic to allow the following: BEGIN_FTR_SECTION or 1,1,1 FTR_SECTION_ELSE or 2,2,2 ALT_FTR_SECTION_END_IFSET(FOO) and the resulting code will be: or 1,1,1 or, or 2,2,2 We achieve this by extending the existing FTR macros. The current feature section semantic just becomes a special case, ie. if the else case is empty we nop out the default case. The key limitation is that the size of the else case must be less than or equal to the size of the default case. If the else case is smaller the remainder of the section is nop'ed. We let the linker put the else case code in with the rest of the text, so that relative branches from the else case are more likley to link, this has the disadvantage that we can't free the unused else cases. This commit introduces the required macro and linker script changes, but does not enable the patching of the alternative sections. We also need to update two hand-made section entries in reg.h and timex.h Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-24 01:32:54 +00:00
*(.text .fixup .text.init.refok .exit.text.refok __ftr_alt_*)
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
#ifdef CONFIG_PPC32
*(.got1)
__got2_start = .;
*(.got2)
__got2_end = .;
#endif /* CONFIG_PPC32 */
} :kernel
. = ALIGN(PAGE_SIZE);
_etext = .;
PROVIDE32 (etext = .);
/* Read-only data */
RODATA
/* Exception & bug tables */
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
__start___ex_table = .;
*(__ex_table)
__stop___ex_table = .;
}
NOTES :kernel :notes
/* The dummy segment contents for the bug workaround mentioned above
near PHDRS. */
.dummy : AT(ADDR(.dummy) - LOAD_OFFSET) {
LONG(0xf177)
} :kernel :dummy
/*
* Init sections discarded at runtime
*/
. = ALIGN(PAGE_SIZE);
__init_begin = .;
.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
_sinittext = .;
INIT_TEXT
_einittext = .;
} :kernel
/* .exit.text is discarded at runtime, not link time,
* to deal with references from __bug_table
*/
.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
EXIT_TEXT
}
.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
INIT_DATA
__vtop_table_begin = .;
*(.vtop_fixup);
__vtop_table_end = .;
__ptov_table_begin = .;
*(.ptov_fixup);
__ptov_table_end = .;
#ifdef CONFIG_PPC_ISERIES
__dt_strings_start = .;
*(.dt_strings);
__dt_strings_end = .;
#endif
}
. = ALIGN(16);
.init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
__setup_start = .;
*(.init.setup)
__setup_end = .;
}
.initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
__initcall_start = .;
INITCALLS
__initcall_end = .;
}
.con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
__con_initcall_start = .;
*(.con_initcall.init)
__con_initcall_end = .;
}
SECURITY_INIT
. = ALIGN(8);
__ftr_fixup : AT(ADDR(__ftr_fixup) - LOAD_OFFSET) {
__start___ftr_fixup = .;
*(__ftr_fixup)
__stop___ftr_fixup = .;
}
. = ALIGN(8);
__lwsync_fixup : AT(ADDR(__lwsync_fixup) - LOAD_OFFSET) {
__start___lwsync_fixup = .;
*(__lwsync_fixup)
__stop___lwsync_fixup = .;
}
#ifdef CONFIG_PPC64
. = ALIGN(8);
__fw_ftr_fixup : AT(ADDR(__fw_ftr_fixup) - LOAD_OFFSET) {
__start___fw_ftr_fixup = .;
*(__fw_ftr_fixup)
__stop___fw_ftr_fixup = .;
}
#endif
#ifdef CONFIG_BLK_DEV_INITRD
. = ALIGN(PAGE_SIZE);
.init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
__initramfs_start = .;
*(.init.ramfs)
__initramfs_end = .;
}
#endif
. = ALIGN(PAGE_SIZE);
.data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) {
__per_cpu_start = .;
*(.data.percpu)
*(.data.percpu.shared_aligned)
__per_cpu_end = .;
}
. = ALIGN(8);
.machine.desc : AT(ADDR(.machine.desc) - LOAD_OFFSET) {
__machine_desc_start = . ;
*(.machine.desc)
__machine_desc_end = . ;
}
2008-08-30 01:43:47 +00:00
. = ALIGN(8);
.dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) { *(.dynsym) }
.dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) }
.dynamic : AT(ADDR(.dynamic) - LOAD_OFFSET)
{
__dynamic_start = .;
*(.dynamic)
}
.hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) }
.interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) }
.rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET)
{
__rela_dyn_start = .;
*(.rela*)
}
powerpc: Sync RPA note in zImage with kernel's RPA note Commit 9b09c6d909dfd8de96b99b9b9c808b94b0a71614 ("powerpc: Change the default link address for pSeries zImage kernels") changed the real-base value in the CHRP note added by the addnote program from 12MB to 32MB to give more space for Open Firmware to load the zImage. (The real-base value says where we want OF to position itself in memory.) However, this change was ineffective on most pSeries machines, because the RPA note added by addnote has the "ignore me" flag set to 1. This was intended to tell OF to ignore just the RPA note, but has the side effect of also making OF ignore the CHRP note (at least on most pSeries machines). To solve this we have to set the "ignore me" flag to 0 in the RPA note. (We can't just omit the RPA note because that is equivalent to having an RPA note with default values, and the default values are not what we want.) However, then we have to make sure the values in the zImage's RPA note match up with the values that the kernel supplies later in prom_init.c with either the ibm,client-architecture-support call or the process-elf-header call in prom_send_capabilities(). So this sets the "ignore me" flag in the RPA note in addnote to 0, and adjusts the RPA note values in addnote.c and in prom_init.c to be consistent with each other and with the values in ibm_architecture_vec. However, since the wrapper is independent of the kernel, this doesn't ensure that the notes will stay consistent. To ensure that, this adds code to addnote.c so that it can extract the kernel's RPA note from the kernel binary and put that in the zImage. To that end, we put the kernel's fake ELF header (which contains the kernel's RPA note) into its own section, and arrange for wrapper to pull out that section with objcopy and pass it to addnote, which then extracts the RPA note from it and transfers it to the zImage. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-08 14:03:29 +00:00
/* Fake ELF header containing RPA note; for addnote */
.fakeelf : AT(ADDR(.fakeelf) - LOAD_OFFSET) { *(.fakeelf) }
/* freed after init ends here */
. = ALIGN(PAGE_SIZE);
__init_end = .;
/*
* And now the various read/write data
*/
. = ALIGN(PAGE_SIZE);
_sdata = .;
#ifdef CONFIG_PPC32
.data : AT(ADDR(.data) - LOAD_OFFSET) {
DATA_DATA
*(.sdata)
*(.got.plt) *(.got)
}
#else
.data : AT(ADDR(.data) - LOAD_OFFSET) {
DATA_DATA
*(.data.rel*)
*(.toc1)
*(.branch_lt)
}
.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
*(.opd)
}
.got : AT(ADDR(.got) - LOAD_OFFSET) {
__toc_start = .;
*(.got)
*(.toc)
}
#endif
. = ALIGN(PAGE_SIZE);
_edata = .;
PROVIDE32 (edata = .);
/* The initial task and kernel stack */
#ifdef CONFIG_PPC32
. = ALIGN(8192);
#else
. = ALIGN(16384);
#endif
.data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
*(.data.init_task)
}
. = ALIGN(PAGE_SIZE);
.data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
*(.data.page_aligned)
}
.data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
*(.data.cacheline_aligned)
}
. = ALIGN(L1_CACHE_BYTES);
.data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
*(.data.read_mostly)
}
. = ALIGN(PAGE_SIZE);
.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
__nosave_begin = .;
*(.data.nosave)
. = ALIGN(PAGE_SIZE);
__nosave_end = .;
}
/*
* And finally the bss
*/
.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
__bss_start = .;
*(.sbss) *(.scommon)
*(.dynbss)
*(.bss)
*(COMMON)
__bss_stop = .;
}
. = ALIGN(PAGE_SIZE);
_end = . ;
PROVIDE32 (end = .);
}