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[2001:8b0:1d0::2]) by smtp.gmail.com with ESMTPSA id k2-20020a05600c1c8200b0040fafd84095sm214735wms.41.2024.02.02.07.36.42 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Feb 2024 07:36:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1706888202; x=1707493002; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=Y9n/AEkxgug8LnVgrJ59ksyGPxf9vBmtyi9ED3ze10g=; b=KtFlnEfD0ebWGaD1JzH11fi3nzN0vd1hVmOnHbNaI4gCXo5KKK9Z+1MhLWW1BD15Zq q4Q0xyy04horfOohhW0qEASezMBKzFZtfk7VqLwjsVhb3+gJgRNZsrWs97igWjmd2QMM 5xuLxD1RrJpmguPRF5J9fE57WNTCMm44RAuTQbGLzR/HZQvRE+83DDRiPTjZBN/7mIV2 UIFPYGCKPO50gQY/IYRixZNIV8bAzi3JlyA1hbbyDZpSuENAWmfN1kUKYCxn560ZPfmL h1TQfhAmsSqAsHTuTAom+kDob1YOSPnXHPeD8jORTDmzDPUBVEGfoONHK8GcXth1si8d og/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706888202; x=1707493002; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Y9n/AEkxgug8LnVgrJ59ksyGPxf9vBmtyi9ED3ze10g=; b=MoZzDo8VHZKHeh87mVkKZWJFwHdV7iNERouqOMvnd6KWCnM456rTpV5pHpf0OS++A5 E/QOG4iLUBx29UNH45cSKfHjAHrHTsEwN37BsbyyJ4c4tjJd62nCMtPuyn5qEtsc5KjI kj3AumEaB2C43Dp/NKKXu3bu+317aIGsuzw/HLoQY+z/qyGz52Dw1jeWi7ZbE7C8vZdB weez693gSCFSNtHpjQc6n0KVX4epzBYJRPZMJB8biOE9AB4LGTQt+5oupcfAoIAG7QYh DRHFwSrnb7x06gmELNqiw8UvwM4daJM+ph/RXJNMc4RtBU7ksgS6fX8OQq4uQnSLGI0Q nuOQ== X-Gm-Message-State: AOJu0YyRNnBJdA9Yjs+mEjAey1gTMJ5kKIV8BZDeMN3zd3geWWfiL6Lc YCcn+C4cUMO40HQLYATTlr05k+HcKipMn44TrfI10KdHhedU5a5TJnuQzryTkyJ1XawKlhUPEst k X-Google-Smtp-Source: AGHT+IEbre5vRsT8iOCWBqioeE41PYliJhhdBjr6PNNkM+ZEkY3/+QZVnyDdRZMUFAUK/JDY96orbA== X-Received: by 2002:a05:600c:314a:b0:40e:7232:bdf9 with SMTP id h10-20020a05600c314a00b0040e7232bdf9mr4624655wmo.16.1706888202722; Fri, 02 Feb 2024 07:36:42 -0800 (PST) From: Peter Maydell To: qemu-devel@nongnu.org Subject: [PULL 08/36] qemu-options.hx: Improve -serial option documentation Date: Fri, 2 Feb 2024 15:36:09 +0000 Message-Id: <20240202153637.3710444-9-peter.maydell@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240202153637.3710444-1-peter.maydell@linaro.org> References: <20240202153637.3710444-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::32e; envelope-from=peter.maydell@linaro.org; helo=mail-wm1-x32e.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1706888297886100001 The -serial option documentation is a bit brief about '-serial none' and '-serial null'. In particular it's not very clear about the difference between them, and it doesn't mention that it's up to the machine model whether '-serial none' means "don't create the serial port" or "don't wire the serial port up to anything". Expand on these points. Signed-off-by: Peter Maydell Reviewed-by: Daniel P. Berrang=C3=A9 Reviewed-by: Philippe Mathieu-Daud=C3=A9 Message-id: 20240122163607.459769-3-peter.maydell@linaro.org --- qemu-options.hx | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/qemu-options.hx b/qemu-options.hx index 484cc21c1fd..40e938c4877 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4129,7 +4129,8 @@ SRST This option can be used several times to simulate up to 4 serial ports. =20 - Use ``-serial none`` to disable all serial ports. + You can use ``-serial none`` to suppress the creation of default + serial devices. =20 Available character devices are: =20 @@ -4151,10 +4152,17 @@ SRST [Linux only] Pseudo TTY (a new PTY is automatically allocated) =20 ``none`` - No device is allocated. + No device is allocated. Note that for machine types which + emulate systems where a serial device is always present in + real hardware, this may be equivalent to the ``null`` option, + in that the serial device is still present but all output + is discarded. For boards where the number of serial ports is + truly variable, this suppresses the creation of the device. =20 ``null`` - void device + A guest will see the UART or serial device as present in the + machine, but all output is discarded, and there is no input. + Conceptually equivalent to redirecting the output to ``/dev/null``. =20 ``chardev:id`` Use a named character device defined with the ``-chardev`` --=20 2.34.1