[PATCH v26 7/7] Documentation: dt: chosen properties for arm64 kdump

[AKASHI Takahiro]

From: James Morse <james.morse at arm.com>

Add documentation for
	linux,crashkernel-base and crashkernel-size,
	linux,elfcorehdr
used by arm64 kexec/kdump to decribe the kdump reserved area, and
the elfcorehdr's location within it.

Signed-off-by: James Morse <james.morse at arm.com>
[takahiro.akashi at linaro.org: added "linux,crashkernel-base" and "-size" ]
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 Documentation/devicetree/bindings/chosen.txt | 30 ++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt
index 6ae9d82..6257ee7 100644
--- a/Documentation/devicetree/bindings/chosen.txt
+++ b/Documentation/devicetree/bindings/chosen.txt
@@ -52,3 +52,33 @@ This property is set (currently only on PowerPC, and only needed on
 book3e) by some versions of kexec-tools to tell the new kernel that it
 is being booted by kexec, as the booting environment may differ (e.g.
 a different secondary CPU release mechanism)
+
+linux,crashkernel-base
+linux,crashkernel-size
+----------------------
+
+These properties (currently used on PowerPC and arm64) indicates
+the base address and the size, respectively, of the reserved memory
+range for crash dump kernel.
+e.g.
+
+/ {
+	chosen {
+		linux,crashkernel-base = <0x9 0xf0000000>;
+		linux,crashkernel-size = <0x0 0x10000000>;
+	};
+};
+
+linux,elfcorehdr
+----------------
+
+This property (currently used only on arm64) holds the memory range,
+the address and the size, of the elf core header which mainly describes
+the panicked kernel's memory layout as PT_LOAD segments of elf format.
+e.g.
+
+/ {
+	chosen {
+		linux,elfcorehdr = <0x9 0xfffff000 0x0 0x800>;
+	};
+};
-- 
2.9.0