docs/system/arm/xlnx-versal-virt: add a note about dumpdtb

Add a note in the DTB section explaining how to dump the generated DTB
using the dumpdtb machine option.

Signed-off-by: Luc Michel <luc.michel@amd.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20250926070806.292065-46-luc.michel@amd.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/docs/system/arm/xlnx-versal-virt.rst b/docs/system/arm/xlnx-versal-virt.rst
index 94c8bacf61a135ddd65a706a94a57afb6581494d..5d7fa18592be7184408c086f5ae130aa961261c0 100644 (file)
--- a/docs/system/arm/xlnx-versal-virt.rst
+++ b/docs/system/arm/xlnx-versal-virt.rst
@@ -65,7 +65,13 @@ When loading an OS, QEMU generates a DTB and selects an appropriate address
 where it gets loaded. This DTB will be passed to the kernel in register x0.
 
 If there's no ``-kernel`` option, we generate a DTB and place it at 0x1000
-for boot-loaders or firmware to pick it up.
+for boot-loaders or firmware to pick it up. To dump and observe the generated
+DTB, one can use the ``dumpdtb`` machine option:
+
+.. code-block:: bash
+
+  $ qemu-system-aarch64 -M amd-versal-virt,dumpdtb=example.dtb -m 2G
+
 
 If users want to provide their own DTB, they can use the ``-dtb`` option.
 These DTBs will have their memory nodes modified to match QEMU's