From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from qs51p00im-qukt01072702.me.com (qs51p00im-qukt01072702.me.com [17.57.155.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 480241E048D for ; Sun, 19 Jan 2025 17:32:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=17.57.155.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737307942; cv=none; b=rCL9B1xk/kzQEtealzGyTcSNyprkjywSMWYVHJJsJXMzKjg9gY+eaLzButTRSNB9/SY73VMVN7gT2S9moa2VRfu2Ph0dFayRXcy13CbnIFa2dfZ9MweNT/qdpFQg7oAYaouyNtRshAJdrqQ8nTrQV9DkOA7GIYdzfmr13TKJy2k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737307942; c=relaxed/simple; bh=TLhs/gILxa2wbWGiD482sqCxASPDicFHnLv53sk/2hM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=J615PTWJwybjezscKKiIvGdlYp7r6IhOcGkH4lfHzR828g5+yng630O63tUnLJu6CM9bLeiWoKhDKC8vUpGyxheqQ1ZHscyQOprZlko2MK1786Re+fH7H4JLfSP4hjGTY5ujp38ozSY0c6x6UYiZrjE2B0MtY+ShDp3389i+x88= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=t4c.dev; spf=pass smtp.mailfrom=t4c.dev; dkim=pass (2048-bit key) header.d=t4c.dev header.i=@t4c.dev header.b=Lmbcn3g6; arc=none smtp.client-ip=17.57.155.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=t4c.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=t4c.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=t4c.dev header.i=@t4c.dev header.b="Lmbcn3g6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=t4c.dev; s=sig1; bh=n3cYYSROnnOT51wYvYcK0RHdr2LVCZwk/pVs/4rATok=; h=From:To:Subject:Date:Message-ID:MIME-Version:x-icloud-hme; b=Lmbcn3g6jw3QMkVx1H2tlRmSE1nVUKojhbT9QlNp/FQhBhkWScoHfedJ2TJQXBHkK RRTq8vFtIvFzF5zVUhCyjxJ33fc9kiguf5rxtRvh4+HdEEgZovu0N7YtYGlGFdqEgE 5KVK7ZNugSaQA8sMPqBe5BSGez82417D2zPKAFdpbqWPfsNQ9i1IlzLVHxG07SzUh0 9KYfzegxkJsoqTuht8EqdCNp7IgkqEmVaGztXMCBUC+kTY7CxSwm6IkZbJr48iifh9 /rLvunCvXbUw2GS8LwzR+QEb5YTERKEPUOzagYQD/LwAJTinGeGgFEpyn8bISdYhEw 494g/XZ5HYf9g== Received: from localhost.localdomain (qs51p00im-dlb-asmtp-mailmevip.me.com [17.57.155.28]) by qs51p00im-qukt01072702.me.com (Postfix) with ESMTPSA id 95A9916803D7; Sun, 19 Jan 2025 17:32:16 +0000 (UTC) From: Hendrik 'T4cC0re' Meyer To: ardb@kernel.org Cc: linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux@t4c.dev Subject: [PATCH] efistub: add efi=quiet parameter to selectively silence efistub alone Date: Sun, 19 Jan 2025 18:32:05 +0100 Message-ID: <20250119173205.2965649-1-linux@t4c.dev> X-Mailer: git-send-email 2.47.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-GUID: iGeDECdHh-dtEZ--NT_PvUDMMUU90k8f X-Proofpoint-ORIG-GUID: iGeDECdHh-dtEZ--NT_PvUDMMUU90k8f X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-01-19_03,2025-01-16_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 suspectscore=0 malwarescore=0 spamscore=0 adultscore=0 clxscore=1030 mlxlogscore=999 mlxscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2501190138 Hello! > Could you explain the use case please? Your concern is that removing 'quiet' from the command line is producing a few additional lines of output from the EFI stub at boot? Sure :) I boot a UKI (with Secure Boot and TPM measurements) with an embedded splash image, and the cmdline 'memtest=2 earlyprintk=serial,ttyS0,115200 console=ttyS0,115200n8' The stub by default (without 'quiet') will print messages regarding the UKI and it being measured into the TPM on the efifb (I assume) rendering on top of the displayed splash image. "EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path" and "EFI stub: Measured initrd data into PCR 9" to be specific. > How is that a problem compared to the fact that you get the entire kernel log printed to the console? Very relevant question. Because of the 'memtest=2' flag, there is a delay during boot, which should be logged (with memtest progress) to the serial console. 'quiet' will silence these logs. > Is every single line printed there relevant to you, and only the ones emitted by the EFI stub are not? Basically, yes. I want the kernel's printk's, but not have the output of the efistub dipsplayed on top of the splash screen of the UKI. I did not find a way to redirect this output, and adding a 'efi=quiet' option seemed like a low hanging fruit. Hendrik