From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Thu, 24 Nov 2016 18:59:44 +0900 Subject: [PATCH v28 9/9] Documentation: dt: chosen properties for arm64 kdump In-Reply-To: <20161124095523.6972-1-takahiro.akashi@linaro.org> References: <20161124095523.6972-1-takahiro.akashi@linaro.org> Message-ID: <20161124095944.7167-1-takahiro.akashi@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: James Morse Add documentation for linux,crashkernel-base and crashkernel-size, linux,usable-memory-range linux,elfcorehdr used by arm64 kdump to decribe the kdump reserved area, and the elfcorehdr's location within it. Signed-off-by: James Morse [takahiro.akashi at linaro.org: added "linux,crashkernel-base" and "-size" ] Signed-off-by: AKASHI Takahiro Cc: devicetree at vger.kernel.org Cc: Rob Herring Cc: Mark Rutland --- Documentation/devicetree/bindings/chosen.txt | 50 ++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 6ae9d82..7b11516 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -52,3 +52,53 @@ 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,usable-memory-range +------------------------- + +This property (currently used only on arm64) holds the memory range, +the base address and the size, which can be used as system ram on +the *current* kernel. Note that, if this property is present, any memory +regions under "memory" nodes in DT blob or ones marked as "conventional +memory" in EFI memory map should be ignored. +e.g. + +/ { + chosen { + linux,usable-memory-range = <0x9 0xf0000000 0x0 0x10000000>; + }; +}; + +The main usage is for crash dump kernel to identify its own usable +memory and exclude, at its boot time, any other memory areas that are +part of the panicked kernel's memory. + +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>; + }; +}; -- 2.10.0