kernel-fxtec-pro1x/arch/arm/kernel/vmlinux.lds.S
Will Deacon 8903826d0c ARM: idmap: populate identity map pgd at init time using .init.text
When disabling and re-enabling the MMU, it is necessary to take out an
identity mapping for the code that manipulates the SCTLR in order to
avoid it disappearing from under our feet. This is useful when soft
rebooting and returning from CPU suspend.

This patch allocates a set of page tables during boot and populates them
with an identity mapping for the .idmap.text section. This means that
users of the identity map do not need to manage their own pgd and can
instead annotate their functions with __idmap or, in the case of assembly
code, place them in the correct section.

Acked-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-06 14:04:14 +00:00

310 lines
6 KiB
ArmAsm

/* ld script to make ARM Linux kernel
* taken from the i386 version by Russell King
* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
*/
#include <asm-generic/vmlinux.lds.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/page.h>
#define PROC_INFO \
VMLINUX_SYMBOL(__proc_info_begin) = .; \
*(.proc.info.init) \
VMLINUX_SYMBOL(__proc_info_end) = .;
#define IDMAP_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__idmap_text_start) = .; \
*(.idmap.text) \
VMLINUX_SYMBOL(__idmap_text_end) = .;
#ifdef CONFIG_HOTPLUG_CPU
#define ARM_CPU_DISCARD(x)
#define ARM_CPU_KEEP(x) x
#else
#define ARM_CPU_DISCARD(x) x
#define ARM_CPU_KEEP(x)
#endif
#if (defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)) || \
defined(CONFIG_GENERIC_BUG)
#define ARM_EXIT_KEEP(x) x
#define ARM_EXIT_DISCARD(x)
#else
#define ARM_EXIT_KEEP(x)
#define ARM_EXIT_DISCARD(x) x
#endif
OUTPUT_ARCH(arm)
ENTRY(stext)
#ifndef __ARMEB__
jiffies = jiffies_64;
#else
jiffies = jiffies_64 + 4;
#endif
SECTIONS
{
/*
* XXX: The linker does not define how output sections are
* assigned to input sections when there are multiple statements
* matching the same input section name. There is no documented
* order of matching.
*
* unwind exit sections must be discarded before the rest of the
* unwind sections get included.
*/
/DISCARD/ : {
*(.ARM.exidx.exit.text)
*(.ARM.extab.exit.text)
ARM_CPU_DISCARD(*(.ARM.exidx.cpuexit.text))
ARM_CPU_DISCARD(*(.ARM.extab.cpuexit.text))
ARM_EXIT_DISCARD(EXIT_TEXT)
ARM_EXIT_DISCARD(EXIT_DATA)
EXIT_CALL
#ifndef CONFIG_HOTPLUG
*(.ARM.exidx.devexit.text)
*(.ARM.extab.devexit.text)
#endif
#ifndef CONFIG_MMU
*(.fixup)
*(__ex_table)
#endif
#ifndef CONFIG_SMP_ON_UP
*(.alt.smp.init)
#endif
*(.discard)
*(.discard.*)
}
#ifdef CONFIG_XIP_KERNEL
. = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
#else
. = PAGE_OFFSET + TEXT_OFFSET;
#endif
.head.text : {
_text = .;
HEAD_TEXT
}
.text : { /* Real text segment */
_stext = .; /* Text and read-only data */
__exception_text_start = .;
*(.exception.text)
__exception_text_end = .;
IRQENTRY_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
IDMAP_TEXT
#ifdef CONFIG_MMU
*(.fixup)
#endif
*(.gnu.warning)
*(.glue_7)
*(.glue_7t)
. = ALIGN(4);
*(.got) /* Global offset table */
ARM_CPU_KEEP(PROC_INFO)
}
RO_DATA(PAGE_SIZE)
#ifdef CONFIG_ARM_UNWIND
/*
* Stack unwinding tables
*/
. = ALIGN(8);
.ARM.unwind_idx : {
__start_unwind_idx = .;
*(.ARM.exidx*)
__stop_unwind_idx = .;
}
.ARM.unwind_tab : {
__start_unwind_tab = .;
*(.ARM.extab*)
__stop_unwind_tab = .;
}
#endif
_etext = .; /* End of text and rodata section */
#ifndef CONFIG_XIP_KERNEL
. = ALIGN(PAGE_SIZE);
__init_begin = .;
#endif
INIT_TEXT_SECTION(8)
.exit.text : {
ARM_EXIT_KEEP(EXIT_TEXT)
}
.init.proc.info : {
ARM_CPU_DISCARD(PROC_INFO)
}
.init.arch.info : {
__arch_info_begin = .;
*(.arch.info.init)
__arch_info_end = .;
}
.init.tagtable : {
__tagtable_begin = .;
*(.taglist.init)
__tagtable_end = .;
}
#ifdef CONFIG_SMP_ON_UP
.init.smpalt : {
__smpalt_begin = .;
*(.alt.smp.init)
__smpalt_end = .;
}
#endif
.init.pv_table : {
__pv_table_begin = .;
*(.pv_table)
__pv_table_end = .;
}
.init.data : {
#ifndef CONFIG_XIP_KERNEL
INIT_DATA
#endif
INIT_SETUP(16)
INIT_CALLS
CON_INITCALL
SECURITY_INITCALL
INIT_RAM_FS
}
#ifndef CONFIG_XIP_KERNEL
.exit.data : {
ARM_EXIT_KEEP(EXIT_DATA)
}
#endif
PERCPU_SECTION(32)
#ifdef CONFIG_XIP_KERNEL
__data_loc = ALIGN(4); /* location in binary */
. = PAGE_OFFSET + TEXT_OFFSET;
#else
__init_end = .;
. = ALIGN(THREAD_SIZE);
__data_loc = .;
#endif
.data : AT(__data_loc) {
_data = .; /* address in memory */
_sdata = .;
/*
* first, the init task union, aligned
* to an 8192 byte boundary.
*/
INIT_TASK_DATA(THREAD_SIZE)
#ifdef CONFIG_XIP_KERNEL
. = ALIGN(PAGE_SIZE);
__init_begin = .;
INIT_DATA
ARM_EXIT_KEEP(EXIT_DATA)
. = ALIGN(PAGE_SIZE);
__init_end = .;
#endif
NOSAVE_DATA
CACHELINE_ALIGNED_DATA(32)
READ_MOSTLY_DATA(32)
/*
* The exception fixup table (might need resorting at runtime)
*/
. = ALIGN(32);
__start___ex_table = .;
#ifdef CONFIG_MMU
*(__ex_table)
#endif
__stop___ex_table = .;
/*
* and the usual data section
*/
DATA_DATA
CONSTRUCTORS
_edata = .;
}
_edata_loc = __data_loc + SIZEOF(.data);
#ifdef CONFIG_HAVE_TCM
/*
* We align everything to a page boundary so we can
* free it after init has commenced and TCM contents have
* been copied to its destination.
*/
.tcm_start : {
. = ALIGN(PAGE_SIZE);
__tcm_start = .;
__itcm_start = .;
}
/*
* Link these to the ITCM RAM
* Put VMA to the TCM address and LMA to the common RAM
* and we'll upload the contents from RAM to TCM and free
* the used RAM after that.
*/
.text_itcm ITCM_OFFSET : AT(__itcm_start)
{
__sitcm_text = .;
*(.tcm.text)
*(.tcm.rodata)
. = ALIGN(4);
__eitcm_text = .;
}
/*
* Reset the dot pointer, this is needed to create the
* relative __dtcm_start below (to be used as extern in code).
*/
. = ADDR(.tcm_start) + SIZEOF(.tcm_start) + SIZEOF(.text_itcm);
.dtcm_start : {
__dtcm_start = .;
}
/* TODO: add remainder of ITCM as well, that can be used for data! */
.data_dtcm DTCM_OFFSET : AT(__dtcm_start)
{
. = ALIGN(4);
__sdtcm_data = .;
*(.tcm.data)
. = ALIGN(4);
__edtcm_data = .;
}
/* Reset the dot pointer or the linker gets confused */
. = ADDR(.dtcm_start) + SIZEOF(.data_dtcm);
/* End marker for freeing TCM copy in linked object */
.tcm_end : AT(ADDR(.dtcm_start) + SIZEOF(.data_dtcm)){
. = ALIGN(PAGE_SIZE);
__tcm_end = .;
}
#endif
NOTES
BSS_SECTION(0, 0, 0)
_end = .;
STABS_DEBUG
.comment 0 : { *(.comment) }
}
/*
* These must never be empty
* If you have to comment these two assert statements out, your
* binutils is too old (for other reasons as well)
*/
ASSERT((__proc_info_end - __proc_info_begin), "missing CPU support")
ASSERT((__arch_info_end - __arch_info_begin), "no machine record defined")