From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B4C5C433F5 for ; Wed, 22 Sep 2021 16:08:16 +0000 (UTC) Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B9D1161090 for ; Wed, 22 Sep 2021 16:08:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B9D1161090 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kroah.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernelnewbies.org Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.94.2) (envelope-from ) id 1mT4mt-0004LK-Dw; Wed, 22 Sep 2021 12:07:59 -0400 Received: from wout3-smtp.messagingengine.com ([64.147.123.19]) by shelob.surriel.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mT4mq-0004L6-DC for kernelnewbies@kernelnewbies.org; Wed, 22 Sep 2021 12:07:56 -0400 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.west.internal (Postfix) with ESMTP id 17DB73201805; Wed, 22 Sep 2021 12:07:53 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute5.internal (MEProxy); Wed, 22 Sep 2021 12:07:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm1; bh=mF4rAbNvweVmTsAJWABYz2pX85G uhSpg73kqK/o0B1A=; b=zvdKe7GWpcAOjISVLLBt/LLxOsmUhP7sv9S8f4PuMYu TpUtTmZVzNTwcxXcFw2qVND8ikiAFA2ggpIPQALbnYC6WTyAow0tAHfUp+x6plLE yhGRMRItXyYqYo7Ed56Lsex4lZ0ILyTQ3rQ6feLyTJUirKCtklMjrxzp5Ew39lyZ 1KX77yZaUTK8muPawan7jL0TZgcL4FTOO0UBDypj1fJnlVmX57wfiXFj21fRLMpe 6eXKS4cmlTQ0OkNAaBZ1wUed0fCy4fB0TCzKt4Hu3SuNSgFrsQ0gz/5fLhFKHzow 9d502dfjEwJYrnxJOuFZh0JDua3eiOit8bc52/us6pg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=mF4rAb NvweVmTsAJWABYz2pX85GuhSpg73kqK/o0B1A=; b=wPBvojfptj1byot2ml0rDy J4LxuEDleNb6WRYg1DD43Jg7ki0Vf9x/aMH3ym71pDScFHPjy/ZSXjG6IeeGFzmb 3dCanbtxaDZl8uECM0PnW1w7e+0K3YxrZ2dhGC+rCo7BXABZ97TntjPnKI2zt/aL fnuAtqxPc/cgLSmpYzTCHqoh9WYhajoYaEns4OwwHg6yt0LIUQ6kOqVrGGPMaBCR iomXKp2y+Vc65uJJt3ekr6B0pU/xwdB0NBkvhkS7n25x0hH/+pMZVD6WbLYGsy9Q KDHCpaC4p7VK9W1Pape9OkCPHjq/8RtDDLPMNq2N32lxlCmcSvQceQSU/t4GLbcg == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrudeijedgleeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefirhgvghcu mffjuceoghhrvghgsehkrhhorghhrdgtohhmqeenucggtffrrghtthgvrhhnpeevueehje fgfffgiedvudekvdektdelleelgefhleejieeugeegveeuuddukedvteenucevlhhushht vghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhh drtghomh X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 22 Sep 2021 12:07:51 -0400 (EDT) Date: Wed, 22 Sep 2021 18:07:49 +0200 From: Greg KH To: Ruben Safir Subject: Re: efivars Message-ID: References: <20210922062222.GA6060@www2.mrbrklyn.com> <20210922154742.GA12004@www2.mrbrklyn.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210922154742.GA12004@www2.mrbrklyn.com> Cc: kernelnewbies@kernelnewbies.org X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kernelnewbies-bounces@kernelnewbies.org On Wed, Sep 22, 2021 at 11:47:42AM -0400, Ruben Safir wrote: > On Wed, Sep 22, 2021 at 08:35:15AM +0200, Greg KH wrote: > > On Wed, Sep 22, 2021 at 02:22:22AM -0400, Ruben Safir wrote: > > > What is this for? > > > > > > efivarfs on /sys/firmware/efi/efivars type efivarfs > > > > > > why would the OS need to know anything about the UEFI > > > boot loader once it is up and running? > > > > Because there are lots of needed system information that the OS, and > > userspace, needs to get from UEFI after the system has booted. > > Such as what? It is not needed when booting with LILO? Do you really still use LILO? > Once the OS is up and running, what possible reason does the OS need > anything about the booting enviroonment? It needs to get up and running. And even then, while running, it still needs to get some information from UEFI. Fun things like device information, system information, and other things. Look at what `dmidecode` gives you, that's one example. > > Why do you think it does not need to be present? What problems is > > having it there causing? > > > > Aside from the obvious security issues? It is a huge problem for > installation from BIOS environments and it is an unneeded lock in. What "lock in"? Your system relies on the bootloader to interact with the system both to boot, and for some system interactions while running. That's just how ACPI/UEFI works. If you don't like this, wonderful, use a system based on a different type of bootloader. But in the end, they end up all having to do the same thing somehow :) > All I want the boot loader to do is fine the kernel and run it. Your bootloader also has to do a lot more things (initialize hardware, provide information to the OS as to what hardware is present, do system-level things like suspend/resume, etc.) > I can't think of anything that a bootload does that should be needed for > a running OS whatsoever. What are EFI variables that are being stored > and manipulated? Look at them and see, it's all there for you to read. The whole UEFI spec is also public as well as a working implementation of the code that is used for your system. thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies