From: anton.ivanov@cambridgegreys.com
To: linux-um@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
kernel@axis.com, robh+dt@kernel.org, jdike@addtoit.com,
johannes@sipsolutions.net, vincent.whitchurch@axis.com,
richard@nod.at, linux-doc@vger.kernel.org,
Anton Ivanov <anton.ivanov@cambridgegreys.com>
Subject: [PATCH] um: Document dtb command line option
Date: Tue, 4 Jan 2022 10:44:57 +0000 [thread overview]
Message-ID: <20220104104457.282828-1-anton.ivanov@cambridgegreys.com> (raw)
In-Reply-To: <1118129237.194759.1640202076897.JavaMail.zimbra@nod.at>
From: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Add documentation for the dtb command line option and the
ability to load/parse device trees.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
---
.../virt/uml/user_mode_linux_howto_v2.rst | 20 +++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/Documentation/virt/uml/user_mode_linux_howto_v2.rst b/Documentation/virt/uml/user_mode_linux_howto_v2.rst
index 2cafd3c3c6cb..81986fe014d4 100644
--- a/Documentation/virt/uml/user_mode_linux_howto_v2.rst
+++ b/Documentation/virt/uml/user_mode_linux_howto_v2.rst
@@ -1189,6 +1189,26 @@ E.g. ``os_close_file()`` is just a wrapper around ``close()``
which ensures that the userspace function close does not clash
with similarly named function(s) in the kernel part.
+Using UML as a Test Platform
+============================
+
+UML is an excellent test platform for device driver development. As
+with most things UML, "some user assembly may be required". It is
+up to the user to build their emulation environment. UML at present
+provides only the kernel infrastructure.
+
+Part of this infrastructure is the ability to load and parse fdt
+device tree blobs as used in Arm or Open Firmware platforms. These
+are supplied as an optional extra argument to the kernel command
+line::
+
+ dtb=filename
+
+The device tree is loaded and parsed at boottime and is accessible by
+drivers which query it. At this moment in time this facility is
+intended solely for development purposes. UML's own devices do not
+query the device tree.
+
Security Considerations
-----------------------
--
2.30.2
next prev parent reply other threads:[~2022-01-04 10:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-21 9:04 [PATCH] um: virtio_uml: allow probing from devicetree Vincent Whitchurch
2021-12-21 20:48 ` Johannes Berg
2021-12-22 10:34 ` Vincent Whitchurch
2021-12-22 11:11 ` Anton Ivanov
2021-12-22 19:41 ` Richard Weinberger
2022-01-04 10:44 ` anton.ivanov [this message]
2022-01-13 15:09 ` [PATCH] um: Document dtb command line option Vincent Whitchurch
2022-01-04 14:13 ` [PATCH] um: virtio_uml: allow probing from devicetree Anton Ivanov
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