[PATCH v7 13/17] ARM: Xen: Document UEFI support on Xen ARM virtual platforms

Shannon Zhao
2016-03-24T14:48:31Z

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: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
Documentation/devicetree/bindings/arm/xen.txt | 33 +++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/xen.txt b/Documentation/devicetree/bindings/arm/xen.txt
index 0f7b9c2..6f83f76 100644
--- a/Documentation/devicetree/bindings/arm/xen.txt
+++ b/Documentation/devicetree/bindings/arm/xen.txt
@@ -15,6 +15,26 @@ the following properties:
- interrupts: the interrupt used by Xen to inject event notifications.
A GIC node is also required.

+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 +42,17 @@ 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.
--
2.1.4