| Message ID | 20161124095944.7167-1-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Nov 24, 2016 at 06:59:44PM +0900, AKASHI Takahiro wrote: > From: James Morse <james.morse@arm.com> > > 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 <james.morse@arm.com> > [takahiro.akashi@linaro.org: added "linux,crashkernel-base" and "-size" ] > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> > Cc: devicetree@vger.kernel.org > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Mark Rutland <mark.rutland@arm.com> Rob, Mark, are you ok with this patch?
On Thu, Nov 24, 2016 at 05:14:13PM +0000, Catalin Marinas wrote: > On Thu, Nov 24, 2016 at 06:59:44PM +0900, AKASHI Takahiro wrote: > > From: James Morse <james.morse@arm.com> > > > > 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 <james.morse@arm.com> > > [takahiro.akashi@linaro.org: added "linux,crashkernel-base" and "-size" ] > > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> > > Cc: devicetree@vger.kernel.org > > Cc: Rob Herring <robh+dt@kernel.org> > > Cc: Mark Rutland <mark.rutland@arm.com> > > Rob, Mark, are you ok with this patch? I'm leaving this one to Mark. Rob
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>; + }; +};