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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B7A32CD98C5 for ; Mon, 15 Jun 2026 17:05:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id: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-Owner; bh=be/KypQX5Q9fujajARM6Q7r9w26ilWIZmzbrtGfAKys=; b=JQGmVRndm/RFL5Nk9vQP4jcsxo DTc8T90Qdy4vRAPHyfpcNGq7fOXUXt4wLfo+5gZFqj5XR+9zkQoSlu3cFWzL4EGIltVXgADd3wbHB fgRaEIkNqgQkCxy3v3d/b3PH/3EC/tp3yXeB3sugxHkZ+u9NF+pns4Fskf4DnOT/8WgTythFDZxOV J0U7j5wGTV4B1zUEvau9v88hIi/AozJ2wqsgAtfRefXh4KdgAjOy5DmpikB2aUo9Bt0SdUAeiV4yj VEEYs+q28F44ywZ2CC4s9QHJwz3t9UQ1mNgm3tSVepxqhYhA3Vhg1zHFhTJwCVpHFVcDFCztuSuQ7 oKDA5sRA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wZAjz-0000000EceN-25l3; Mon, 15 Jun 2026 17:04:51 +0000 Received: from zeniv.linux.org.uk ([2a03:a000:7:0:5054:ff:fe1c:15ff]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wZAjw-0000000EccV-1LFM; Mon, 15 Jun 2026 17:04:50 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; 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; bh=be/KypQX5Q9fujajARM6Q7r9w26ilWIZmzbrtGfAKys=; b=SLabnQnxi8RKG6kB4YLIrRrIte +jYEaBgX5DOoDOdPOU6k6ypOK6lDxxOMXQzKEUszFj5yTLPDASBaagrmnsOk8tUGdmzHw2XGk68HM 2J1tv7+pE0CjbBOIjeYCz0TsyHOIrqFb8Mb1LadfEs+3t0bUVsavfv//KIZ2S3hmTXIBIqEbnE3qn zsd3Hxu29/Ylu8C3lRKI+WwMxWxUWcLIz0u0fTGyYSKAR/XPPXo0Rkv03xUIJElu5cOtap9hCSZj1 74eb7LaTsGudBKuTsb4/IH254uFPRDECMTh8XzLqKRh9ykQzpGUZV9OECxDmxcCHO22vobRU+rK1T RNRNGWLQ==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.99.2 #2 (Red Hat Linux)) id 1wZAjg-00000000Vxn-0xg6; Mon, 15 Jun 2026 17:04:32 +0000 Date: Mon, 15 Jun 2026 18:04:32 +0100 From: Al Viro To: Vincent Mailhol Cc: Jens Axboe , Davidlohr Bueso , Christian Brauner , Jan Kara , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-efi@vger.kernel.org, linux-fsdevel@vger.kernel.org, Richard Henderson , Matt Turner , Magnus Lindholm , linux-alpha@vger.kernel.org, Vineet Gupta , linux-snps-arc@lists.infradead.org, Russell King , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , loongarch@lists.linux.dev, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org, Heiko Carstens , Vasily Gorbik , Alexander Gordeev , linux-s390@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Jonathan Corbet , Shuah Khan , linux-doc@vger.kernel.org Subject: Re: [PATCH 00/19] init: discoverable root partitions, a.k.a. an omittable "root=" cmdline option Message-ID: <20260615170432.GW2636677@ZenIV> References: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260615_100448_361505_AF6F34A6 X-CRM114-Status: GOOD ( 12.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jun 15, 2026 at 06:08:56PM +0200, Vincent Mailhol wrote: > Tested with GRUB, which implements the LoaderDevicePartUUID EFI variable > in its bli module [3]. With this, I was able to boot a kernel with a > completely empty cmdline and no initrd. > > [1] The Discoverable Partitions Specification (DPS) > Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/ > > [2] systemd-gpt-auto-generator > Link: https://www.freedesktop.org/software/systemd/man/latest/systemd-gpt-auto-generator.html > > [3] GRUB -- §16.2 bli > Link: https://www.gnu.org/software/grub/manual/grub/html_node/bli_005fmodule.html So what does that thing, tied to EFI as it is, have to do with architectures where * firmware is rather unlike EFI * firmware wouldn't know what to do with GPT * GRUB is *not* ported to, let alone used such as, say it, the very first one mentioned at your [1]? Or is that conditional upon "if anyone wants to design replacement firmware for those, and if they agree to follow our wishlist"?