From patchwork Tue Jan 4 10:44:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Ivanov X-Patchwork-Id: 1575164 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=QR7y2tsF; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:e::133; helo=bombadil.infradead.org; envelope-from=linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4JSq5w1rnfz9sXM for ; Tue, 4 Jan 2022 21:45:56 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=04/hh+yaKF8GqHPZYdKPJ/YkPWZUEVDhwxZTdPyVCQM=; b=QR7y2tsFdVGn8P DTfdFsSiiJ7M9+W+Kxro5jhwq+uWU5iRwrj592MGQD4BV9ol2U+1yyil4ESlL0SpO+MUR8GwFriSW J01JcvguZiftoeo3GY+Oh4FHJL1L2Y8hO4JDgHSp7efQu4VvaR8kWecAY+3jen91r/jHiH44FbrLE L+MNEeIEKm8PcQSXOtvyXnhjfmSMj6C7GvPImiT+T9Vl2IK14RpePMPcavvIywU2OrstOGFvnvXUx V92oWLoCEKONqMXq5C6SbEMNctznHduwAB08iHRYH5og8nHH2caqly0ilWYHSOnKXRGsKVxts3mjQ P0myWGSSTBxpfsSmCGyA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4hK5-00BBmE-0c; Tue, 04 Jan 2022 10:45:45 +0000 Received: from ivanoab7.miniserver.com ([37.128.132.42] helo=www.kot-begemot.co.uk) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4hK2-00BBjJ-1K for linux-um@lists.infradead.org; Tue, 04 Jan 2022 10:45:43 +0000 Received: from [192.168.18.6] (helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n4hJo-00089g-BW; Tue, 04 Jan 2022 10:45:32 +0000 Received: from jain.kot-begemot.co.uk ([192.168.3.3]) by jain.kot-begemot.co.uk with esmtp (Exim 4.94.2) (envelope-from ) id 1n4hJi-001BhW-DX; Tue, 04 Jan 2022 10:45:24 +0000 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 Subject: [PATCH] um: Document dtb command line option Date: Tue, 4 Jan 2022 10:44:57 +0000 Message-Id: <20220104104457.282828-1-anton.ivanov@cambridgegreys.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <1118129237.194759.1640202076897.JavaMail.zimbra@nod.at> References: <1118129237.194759.1640202076897.JavaMail.zimbra@nod.at> MIME-Version: 1.0 X-Spam-Score: -1.0 X-Spam-Score: -1.0 X-Clacks-Overhead: GNU Terry Pratchett X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220104_024542_102925_0F349108 X-CRM114-Status: GOOD ( 11.25 ) X-Spam-Score: 0.4 (/) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: From: Anton Ivanov Add documentation for the dtb command line option and the ability to load/parse device trees. Signed-off-by: Anton Ivanov --- .../virt/uml/user_mode_linux_howto_v2.rst | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+) Content analysis details: (0.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.4 KHOP_HELO_FCRDNS Relay HELO differs from its IP's reverse DNS X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Anton Ivanov Add documentation for the dtb command line option and the ability to load/parse device trees. Signed-off-by: Anton Ivanov Reviewed-by: Vincent Whitchurch --- .../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 -----------------------