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Commit 5e1743c0 authored by Frank Rowand's avatar Frank Rowand Committed by Rob Herring
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of: document /sys/firmware/fdt 



Add ABI documentation for /sys/firmware/fdt

Update contact email for /sys/firmware/devicetree/* and add mail list

Signed-off-by: default avatarFrank Rowand <frank.rowand@sony.com>
Acked-by: default avatarGrant Likely <grant.likely@arm.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent ce437750

Documentation/ABI/testing/sysfs-firmware-ofw

+25 −1
Original line number Diff line number Diff line 
What:		/sys/firmware/devicetree/*

Date:		November 2013

Contact:	Grant Likely <grant.likely@linaro.org>

Contact:	Grant Likely <grant.likely@arm.com>, devicetree@vger.kernel.org

Description:

		When using OpenFirmware or a Flattened Device Tree to enumerate

		hardware, the device tree structure will be exposed in this
@@ -26,3 +26,27 @@ Description: 
		name plus address). Properties are represented as files

		in the directory. The contents of each file is the exact

		binary data from the device tree.



What:		/sys/firmware/fdt

Date:		February 2015

KernelVersion:	3.19

Contact:	Frank Rowand <frowand.list@gmail.com>, devicetree@vger.kernel.org

Description:

		Exports the FDT blob that was passed to the kernel by

		the bootloader. This allows userland applications such

		as kexec to access the raw binary. This blob is also

		useful when debugging since it contains any changes

		made to the blob by the bootloader.



		The fact that this node does not reside under

		/sys/firmware/device-tree is deliberate: FDT is also used

		on arm64 UEFI/ACPI systems to communicate just the UEFI

		and ACPI entry points, but the FDT is never unflattened

		and used to configure the system.



		A CRC32 checksum is calculated over the entire FDT

		blob, and verified at late_initcall time. The sysfs

		entry is instantiated only if the checksum is valid,

		i.e., if the FDT blob has not been modified in the mean

		time. Otherwise, a warning is printed.

Users:		kexec, debugging