docs: Add documentation on the supported qemuarm-efi machine

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

docs/build-flavours/linux-flavour.rst

@@ -23,6 +23,7 @@ Supported machines (default in **bold**):
 * **qemux86-64**
 * qemux86
 * qemuarm64-efi
+* qemuarm-efi
 * seco-intel-b68 (SECO SBC-B68)
 * seco-imx8mm-c61-2gb (SECO SBC-C61 2GB DRAM)
 * seco-imx8mm-c61-4gb (SECO SBC-C61 4GB DRAM)

docs/hardware-support/virtual-boards/index.rst

@@ -15,3 +15,4 @@ This section details the support for virtual targets in |main_project_name|.
    qemux86-64
    qemux86
    qemuarm64-efi
+   qemuarm-efi

docs/hardware-support/virtual-boards/qemuarm-efi.rst

+.. SPDX-FileCopyrightText: Huawei Inc.
+..
+.. SPDX-License-Identifier: CC-BY-4.0
+
+.. include:: ../../definitions.rst
+
+Qemu ARM 32bit
+##############
+
+.. contents:: 
+   :depth: 4
+
+Overview
+********
+
+|main_project_name| supports running the software stack into an virtual
+environment using Qemu.
+
+Building an Oniro image
+=======================
+
+To clone the source code, perform the procedure in: :ref:`Setting up a repo
+workspace <RepoWorkspace>`.
+
+Building a Linux image
+======================
+
+Build Steps
+-----------
+
+1. Source the environment with proper template settings, flavour being *linux*
+   and target machine being *qemuarm-efi*. Pay attention to how relative
+   paths are constructed. The value of *TEMPLATECONF* is relative to the
+   location of the build directory *./build-oniro-linux*, that is going to be
+   created after this step:
+
+.. code-block:: console
+
+   $ TEMPLATECONF=../oniro/flavours/linux . ./oe-core/oe-init-build-env build-oniro-linux
+
+2. You will find yourself in the newly created build directory. Call *bitbake*
+   to build the image. For example, if you are using *oniro-image-base*
+   run the following command:
+
+.. code-block:: console
+
+   $ MACHINE=qemuarm-efi bitbake oniro-image-base
+
+Once the image is done, you can run the Qemu using the provided script wrapper:
+
+.. code-block:: console
+
+   $ MACHINE=qemuarm-efi runqemu oniro-image-base nographic slirp