From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 D9D8118A93C for ; Mon, 31 Mar 2025 12:55:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743425742; cv=none; b=jnKe7EsFxljkpkoglfoqjFrEBQG28VYndobgPy52qmxEQzvEHeMPrtU3fZjDX5zxIYzO8ilzfY5wkQYPd6MIAvPjVk7fIe65HTAOwlpI0wUqtXghYlcX3LKORthiFMkzwSA9OKMZuSEsbAgPHewSuV+twynpOeMLj0twXnRB4dM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743425742; c=relaxed/simple; bh=Id97AnoxrUwH4BcAbsdLWu1m33yWfZwea34RKwUDQaA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nuur/amZiA2Wz4AgD/GK94EGZI2y3gmL+IefqJk0elTs5cmiEbbS2w5VnMdq4Ky0vJt3Lir6ScHE5sweByoQN02Zx7luJAFcAsrwwinzk+tAOPKQe5apd/6LGagBzVTi4k61mgMR1fochcoWXOPV+z1/IH5frZNE9J2N97fMj9I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=jGw3wIGT; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="jGw3wIGT" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=dp6/ZhxCBVGkVXKOH8cc/tdyF4DuQ/89efi02sHN7io=; b=jGw3wIGTchIihlce0544VoMdve 2QcylGK9Zh7Q/cMQeeS+r+XdkJZWbF2aRN3LqePd/gnDa/LSuuEub6Vs5mOtam8cSYAq+gI/qdPJH ijc1moomOwdi2D8Cu+uZONlzlDGsSVLXfK5bOMTd/dpiNdMz/wtmYbn6kbDMtcwJyIuLZiM1Eq0as Dxlmn47QbeYH9Fqu+TsMS2IycK3P5dptJbx2zOEI2Wk86vdvgxPpndB1NdOB+hoaeXuntbi6DcXLA DptihaCqogaRsQAAWvSQgTLhBLrdT/r7UnwrJU7RGZFfQXDSzpUK/PavpWrAS6/uGGgv4V4y0fTe3 wEpT3O3w==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:40534) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tzEfp-00040G-29; Mon, 31 Mar 2025 13:55:29 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.96) (envelope-from ) id 1tzEfj-0001gX-2Y; Mon, 31 Mar 2025 13:55:23 +0100 Date: Mon, 31 Mar 2025 13:55:23 +0100 From: "Russell King (Oracle)" To: =?utf-8?B?6LCi6Ie06YKmIChYSUUgWmhpYmFuZyk=?= Cc: ardb@kernel.org, bjorn.andersson@sonyericsson.com, dave@vasilevsky.ca, ebiggers@google.com, linus.walleij@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, liuyuntao12@huawei.com, lumag@kernel.org, masahiroy@kernel.org, nathan@kernel.org, nico@fluxnic.net, oskar.andero@sonyericsson.com, ruanjinjie@huawei.com, victor.boivie@sonyericsson.com Subject: Re: Re: [PATCH] ARM: Fix support for CMDLINE_EXTEND Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: Russell King (Oracle) On Mon, Mar 31, 2025 at 08:29:21AM +0000, 谢致邦 (XIE Zhibang) wrote: > > Later arguments override earlier arguments. Any compiled-in command line > > needs to be overridable by user supplied input from the boot loader. The > > current behaviour is correct. > > CMDLINE_EXTEND is for the built-in command line to "Extend bootloader kernel > arguments", not for the bootloader command line to extend/override built-in > command line. > > Don't forget that the default empty CMDLINE already gives the bootloader the > ability to override everything. Not to mention that even if CMDLINE is not > empty, the default CMDLINE_FROM_BOOTLOADER continues to give the bootloader the > ability to override all. The help text: + The command-line arguments provided by the boot loader will be + appended to the default kernel command string. so, you end up with default kernel command string _followed by_ the boot loader arguments. This allows the boot loader arguments to override anything that is in the default kernel command string. That's why it is a _default_ - it can be overrided. If the boot loader command string is extended by the default kernel command string, then that doesn't happen. CMDLINE_EXTEND is default _followed by_ boot loader. You're wanting it to be the other way around. That's broken. No. Sorry. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!