Commit 9d2f145f authored by Shannon Zhao's avatar Shannon Zhao Committed by David Vrabel
Browse files

ARM: Xen: Document UEFI support on Xen ARM virtual platforms 



Add a "uefi" node under /hypervisor node in FDT, then Linux kernel could
scan this to get the UEFI information.

CC: Rob Herring <robh@kernel.org>
Signed-off-by: default avatarShannon Zhao <shannon.zhao@linaro.org>
Acked-by: default avatarRob Herring <robh@kernel.org>
Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: default avatarJulien Grall <julien.grall@arm.com>
parent 9b08aaa3

Documentation/devicetree/bindings/arm/xen.txt

+35 −0
Original line number Diff line number Diff line
@@ -11,10 +11,32 @@ the following properties: 
  memory where the grant table should be mapped to, using an

  HYPERVISOR_memory_op hypercall. The memory region is large enough to map

  the whole grant table (it is larger or equal to gnttab_max_grant_frames()).

  This property is unnecessary when booting Dom0 using ACPI.



- interrupts: the interrupt used by Xen to inject event notifications.

  A GIC node is also required.

  This property is unnecessary when booting Dom0 using ACPI.



To support UEFI on Xen ARM virtual platforms, Xen populates the FDT "uefi" node

under /hypervisor with following parameters:



________________________________________________________________________________

Name                      | Size   | Description

================================================================================

xen,uefi-system-table     | 64-bit | Guest physical address of the UEFI System

			  |	   | Table.

--------------------------------------------------------------------------------

xen,uefi-mmap-start       | 64-bit | Guest physical address of the UEFI memory

			  |	   | map.

--------------------------------------------------------------------------------

xen,uefi-mmap-size        | 32-bit | Size in bytes of the UEFI memory map

                          |        | pointed to in previous entry.

--------------------------------------------------------------------------------

xen,uefi-mmap-desc-size   | 32-bit | Size in bytes of each entry in the UEFI

                          |        | memory map.

--------------------------------------------------------------------------------

xen,uefi-mmap-desc-ver    | 32-bit | Version of the mmap descriptor format.

--------------------------------------------------------------------------------



Example (assuming #address-cells = <2> and #size-cells = <2>):
@@ -22,4 +44,17 @@ hypervisor { 
	compatible = "xen,xen-4.3", "xen,xen";

	reg = <0 0xb0000000 0 0x20000>;

	interrupts = <1 15 0xf08>;

	uefi {

		xen,uefi-system-table = <0xXXXXXXXX>;

		xen,uefi-mmap-start = <0xXXXXXXXX>;

		xen,uefi-mmap-size = <0xXXXXXXXX>;

		xen,uefi-mmap-desc-size = <0xXXXXXXXX>;

		xen,uefi-mmap-desc-ver = <0xXXXXXXXX>;

        };

};



The format and meaning of the "xen,uefi-*" parameters are similar to those in

Documentation/arm/uefi.txt, which are provided by the regular UEFI stub. However

they differ because they are provided by the Xen hypervisor, together with a set

of UEFI runtime services implemented via hypercalls, see

http://xenbits.xen.org/docs/unstable/hypercall/x86_64/include,public,platform.h.html.

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