doc: update OVMF usage for acrn-dm

Tracked-On: #1832
Signed-off-by: Peter Fang <peter.fang@intel.com>

doc/developer-guides/hld/hld-devicemodel.rst

@@ -53,7 +53,8 @@ options:
 
    acrn-dm [-abehuwxACHPSTWY] [-c vcpus] [-g <gdb port>] [-l <lpc>]
                [-m mem] [-p vcpu:hostcpu] [-s <pci>] [-U uuid]
-               [--vsbl vsbl_file_name] [--part_info part_info_name]
+               [--vsbl vsbl_file_path] [--ovmf ovmf_file_path]
+               [--part_info part_info_name]
                [--enable_trusty] [--intr_monitor param_setting] <vm>
 
        -a: local apic is in xAPIC mode (deprecated)
@@ -84,6 +85,7 @@ options:
        -v: version
        -i: ioc boot parameters
        --vsbl: vsbl file path
+       --ovmf: ovmf file path
        --part_info: guest partition info file path
        --enable_trusty: enable trusty for guest
        --ptdev_no_reset: disable reset check for ptdev
@@ -96,6 +98,7 @@ configuration options.
 Here's an example showing how to run a VM with:
 
 -  Build ACPI table
+-  vSBL as the boot ROM
 -  UART device on PCI 00:01.0
 -  GPU device on PCI 00:02.0
 -  Virtio-block device on PCI 00:03.0

doc/user-guides/acrn-dm-parameters.rst

@@ -213,6 +213,19 @@ Here are descriptions for each of these ``acrn-dm`` command line parameters:
 
        uses ``/usr/share/acrn/bios/VSBL.bin`` as the vSBL image
 
+   * - :kbd:`--ovmf <ovmf_file_path>`
+     - Open Virtual Machine Firmware (OVMF) is an EDK II based project to enable
+       UEFI support for Virtual Machines.
+
+       ACRN currently does not support off-the-shelf OVMF builds targeted for
+       QEMU and KVM. This feature is still under development.
+
+       usage::
+
+          --ovmf <path to OVMF.fd>
+
+       uses ``OVMF.fd`` as the OVMF image
+
    * - :kbd:`-W, --virtio_msix`
      - This option forces virtio to use single-vector MSI.
        By default, any virtio-based devices will use MSI-X as its interrupt