[PATCH v2 2/3] docs: sbsa: document platform version changes

[Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>]

We plan to start using sbsa-ref platform version fields
in DT so firmware does not have to use hardcoded values.

Signed-off-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
---
 docs/system/arm/sbsa.rst | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/docs/system/arm/sbsa.rst b/docs/system/arm/sbsa.rst
index 016776aed8..922a29700d 100644
--- a/docs/system/arm/sbsa.rst
+++ b/docs/system/arm/sbsa.rst
@@ -6,16 +6,35 @@ any real hardware the ``sbsa-ref`` board intends to look like real
 hardware. The `Server Base System Architecture
 <https://developer.arm.com/documentation/den0029/latest>`_ defines a
 minimum base line of hardware support and importantly how the firmware
-reports that to any operating system. It is a static system that
-reports a very minimal DT to the firmware for non-discoverable
-information about components affected by the qemu command line (i.e.
-cpus and memory). As a result it must have a firmware specifically
-built to expect a certain hardware layout (as you would in a real
-machine).
+reports that to any operating system.
 
 It is intended to be a machine for developing firmware and testing
 standards compliance with operating systems.
 
+Platform versions
+"""""""""""""""""
+
+QEMU 7.1 brought support for "platform version major/minor" fields in
+DeviceTree.
+
+Version 0.0
+'''''''''''
+
+It is a static system that reports a very minimal DT to the firmware for
+non-discoverable information about components affected by the qemu
+command line (i.e. cpus and memory). As a result it must have a firmware
+specifically built to expect a certain hardware layout (as you would in
+a real machine).
+
+Version 0.1
+'''''''''''
+
+Additional data are provided in DT to the firmware:
+  - address and size of GIC Distributor
+  - address and size of GIC Redistributor
+
+Simple "/intc/reg" field is used.
+
 Supported devices
 """""""""""""""""
 
-- 
2.40.1