From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 98A8A1C84D0; Mon, 15 Jun 2026 20:33:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781555602; cv=none; b=n443sX1xPIpoZVt6SPAh37PyCCuFL/0F12zCj/eit4wkE2YvpjsSxPpFCuB/cNGxcL/QEuAlChpaTgHfwSHfK40HlIfz5QQAZ0+PUjW7FdNhiIoJ7vlQTnicnFYNCDmQrENJjIHdAVi/olelZtjS4FhKPoKtSM/F88Oy4jleP9s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781555602; c=relaxed/simple; bh=9Z4Q+BvDBzDR3RYOg8ewj62G0BIToP4WyuMbIhRXeBc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CjWc7Y5Kb9piihbqZB8q2IAmM9lNEbMw3NW/0uLTMKmRjYLda/Vd701CRA7QkcJ4qNJsnMhI+0QKtgN7WM1c60T0wVsN+KkGWqEd1yrGM97wyCdc+ay5SncCL7EYlTWhcX5ICatTza1SCg/pdSTrZ+2wdj1QTIEXDiBzxhdCoNY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E86R2Mc0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="E86R2Mc0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D89131F000E9; Mon, 15 Jun 2026 20:33:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781555601; bh=as7Ogfoc/AyskAy2+J9eXyhxUhgDui71XAx+CHT5Mew=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=E86R2Mc0QLlmn6hDEj5MnafzRYyOh8VthGPhggOCVEqZ9xx+sywlJb7QXeIaMbEFA rvREbsI3Zv0iMBuDfYoDef4TgGcmk0gnzth2mBKPpYT5zfQfxZKaETEbxVznMvRfoH piXE10ylpTWfk/t+pECRYcy/iMGYN/iwRMhVbs6e5bPwfcEmSrgpliHOIWdD3C35KZ 3dd4XZnD7RANNMAcrkEHv2ZJgOVbQ7VfGmUoC1gB6jeJzKn1pSM0YTSpCEnNMVRUEO 3IE0flzeBTi4viwUUEYjyjwYKI+KhiEhnh6PLe1a+NU0sfU6WVODjevHGI2ZZiYcfX AyBnvEPDADOhQ== Message-ID: <131a450f-f9c6-464c-8e4e-a4c7a29fb5de@kernel.org> Date: Mon, 15 Jun 2026 22:33:11 +0200 Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 00/19] init: discoverable root partitions, a.k.a. an omittable "root=" cmdline option To: Al Viro 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 References: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org> <20260615170432.GW2636677@ZenIV> From: Vincent Mailhol Content-Language: en-US Autocrypt: addr=mailhol@kernel.org; keydata= xjMEZluomRYJKwYBBAHaRw8BAQdAf+/PnQvy9LCWNSJLbhc+AOUsR2cNVonvxhDk/KcW7FvN JFZpbmNlbnQgTWFpbGhvbCA8bWFpbGhvbEBrZXJuZWwub3JnPsKZBBMWCgBBFiEE7Y9wBXTm fyDldOjiq1/riG27mcIFAmdfB/kCGwMFCQp/CJcFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcC F4AACgkQq1/riG27mcKBHgEAygbvORJOfMHGlq5lQhZkDnaUXbpZhxirxkAHwTypHr4A/joI 2wLjgTCm5I2Z3zB8hqJu+OeFPXZFWGTuk0e2wT4JzjgEZx4y8xIKKwYBBAGXVQEFAQEHQJrb YZzu0JG5w8gxE6EtQe6LmxKMqP6EyR33sA+BR9pLAwEIB8J+BBgWCgAmFiEE7Y9wBXTmfyDl dOjiq1/riG27mcIFAmceMvMCGwwFCQPCZwAACgkQq1/riG27mcJU7QEA+LmpFhfQ1aij/L8V zsZwr/S44HCzcz5+jkxnVVQ5LZ4BANOCpYEY+CYrld5XZvM8h2EntNnzxHHuhjfDOQ3MAkEK In-Reply-To: <20260615170432.GW2636677@ZenIV> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 15/06/2026 at 19:04, Al Viro wrote: > 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 -- ยง16.2 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 I made CONFIG_DPS_ROOT_AUTO_DISCOVERY depend on CONFIG_EFI for this reason. > * 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]? Fair point. I just did: $ git grep "^config EFI$" arch/arm/Kconfig:config EFI arch/arm64/Kconfig:config EFI arch/loongarch/Kconfig:config EFI arch/riscv/Kconfig:config EFI arch/x86/Kconfig:config EFI Anything not in this list is dead code at the moment. > Or is that conditional upon "if anyone wants to design replacement firmware > for those, and if they agree to follow our wishlist"? No, it was just an oversight from my side. I will just keep arm, arm64, loongarch, riscv and x86 in my v2. Yours sincerely, Vincent Mailhol