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[2001:8b0:1d0::2]) by smtp.gmail.com with ESMTPSA id e15-20020a5d530f000000b003391720fa51sm9188728wrv.60.2024.01.22.08.36.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jan 2024 08:36:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1705941370; x=1706546170; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=2Dl719vf+4e7ak89dH3QgvfFZRLc4oDS4GdFH0txpAw=; b=o1Bi6Yza62OnhVNOELHw0dAVYgrZLboieoBk17ZSOK/mU6eCCJe2LN07plf07C8L3x VNfId6IEz08aL65fdt/oDdBvyERAib2LijjXcHANjWTqEA6oSEqcDIjXO3VOfkNX1qwB zB83WaaXKxm4hRRV2qjxjxSWZroEtmsy/A6RkKHjFPbo8hsTkZRYpQjzGdJ+igUlhTRT NfpVJiVHFUkVV/+9D/Ep9F+yGGA+Sd75diaHSIM93i5FJ1hbFdCAdM91fmvd5+bsGEgT tXVKhCQmP98uyey555x+97hAu7OU59XpDl83X5hyPjZYr2vRjq0n+uJpPFfEe2k7fuxO /UVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705941370; x=1706546170; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2Dl719vf+4e7ak89dH3QgvfFZRLc4oDS4GdFH0txpAw=; b=XT6gQ87rcQGW6zBvSGfCrTm8N2jwujj5bohkVqorK7Ni9OPlMMrQAr3WrYr+YPYHIp DrrbYYI90stX0KuOxTQZ6h60BeU56ilzr8/Sh/LE2/CTBGnCUA31a80KfWxTvttiIMvv q/gBEcBK9u2v4Jx+9xxOAbQijnOEpRZrGKAbRps90gFD+MjumCrTkVReFv5l1iUkq2tZ sZ1ixbnSihpnCi8sf/JXfe40ZjBNGtq96bpJB91MuI5hqH/UoJgPC5hhqErwlHMjAaU7 ntIJD/taL92zcbirYherhRpzzMxpG13QRbsNGicS3oRFFdkIWgCDTrjSewLZaqshagSe mZbA== X-Gm-Message-State: AOJu0Yy2y4sWvEqpWYzdLw6+fKQ5miQzddeClcxG8XfmsrOVRb5WKKZH wwT8B7gJxstDtl58JJQ5rIU3hVEu6gLH+4VcSVgiM7/yBn18ZgeIjogooqpjeP9M+nAXSntkL66 H X-Google-Smtp-Source: AGHT+IHmDJnOxFc9GVz+rsAfolD/ZvBB9VEF5TMHiNk18EjNfUm9xZdXBVbtTPmipnshWZoO4Zw7Rw== X-Received: by 2002:a05:6000:dcf:b0:337:c5fb:c851 with SMTP id dw15-20020a0560000dcf00b00337c5fbc851mr2892718wrb.8.1705941370485; Mon, 22 Jan 2024 08:36:10 -0800 (PST) From: Peter Maydell To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Bohdan Kostiv , Markus Armbruster , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Subject: [PATCH 2/2] qemu-options.hx: Improve -serial option documentation Date: Mon, 22 Jan 2024 16:36:07 +0000 Message-Id: <20240122163607.459769-3-peter.maydell@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240122163607.459769-1-peter.maydell@linaro.org> References: <20240122163607.459769-1-peter.maydell@linaro.org> MIME-Version: 1.0 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::431; envelope-from=peter.maydell@linaro.org; helo=mail-wr1-x431.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=unavailable 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: 1705941457373100003 Content-Type: text/plain; charset="utf-8" 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 --- qemu-options.hx | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/qemu-options.hx b/qemu-options.hx index ced82848637..d8c3fe91de1 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