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authorMatthew Leach <matthew.leach@arm.com>2012-09-21 18:56:02 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-09-26 22:58:36 +0100
commit4cabd1d9625c7d88acd143f4021fbef75394f154 (patch)
tree3c232277c6bd94c7c4f17714de2104652735bdfb /arch/arm/kernel
parent559a593905e583fca23229b916c016e5211c6766 (diff)
ARM: 7539/1: kexec: scan for dtb magic in segments
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>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/machine_kexec.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
index dfcdb9f7c12..dee34efca74 100644
--- a/arch/arm/kernel/machine_kexec.c
+++ b/arch/arm/kernel/machine_kexec.c
@@ -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,