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ARM: 7539/1: kexec: scan for dtb magic in segments

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This patch allows a dtb to be passed to a new kernel using the kexec
mechinism.

When loading segments from userspace, scan each segment's first four
bytes for the dtb magic. If this is found set the kexec_boot_atags
parameter to the relocate_kernel code to the phyical address of this
segment.

Reviewed-by: Simon Horman <horms@verge.net.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Matthew Leach 2012-09-21 18:56:02 +01:00 committed by Russell King
parent 559a593905
commit 4cabd1d962
1 changed files with 22 additions and 1 deletions
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23
arch/arm/kernel/machine_kexec.c
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@ -9,6 +9,7 @@
#include <linux/io.h>
#include <linux/irq.h>
#include <asm/pgtable.h>
#include <linux/of_fdt.h>
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
@ -32,6 +33,24 @@ static atomic_t waiting_for_crash_ipi;
int machine_kexec_prepare(struct kimage *image)
{
struct kexec_segment *current_segment;
__be32 header;
int i, err;
/*
* No segment at default ATAGs address. try to locate
* a dtb using magic.
*/
for (i = 0; i < image->nr_segments; i++) {
current_segment = &image->segment[i];
err = get_user(header, (__be32*)current_segment->buf);
if (err)
return err;
if (be32_to_cpu(header) == OF_DT_HEADER)
kexec_boot_atags = current_segment->mem;
}
return 0;
}
@ -122,7 +141,9 @@ void machine_kexec(struct kimage *image)
kexec_start_address = image->start;
kexec_indirection_page = page_list;
kexec_mach_type = machine_arch_type;
kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
if (!kexec_boot_atags)
kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
/* copy our kernel relocation code to the control code page */
memcpy(reboot_code_buffer,