From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gardel.0pointer.net (gardel.0pointer.net [85.214.157.71]) (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 D969E13FF1 for ; Sat, 16 Dec 2023 14:41:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=poettering.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=poettering.net Received: from gardel-login.0pointer.net (gardel-mail [IPv6:2a01:238:43ed:c300:10c3:bcf3:3266:da74]) by gardel.0pointer.net (Postfix) with ESMTP id 3C32DE80406; Sat, 16 Dec 2023 15:34:03 +0100 (CET) Received: by gardel-login.0pointer.net (Postfix, from userid 1000) id EA87516036B; Sat, 16 Dec 2023 15:34:02 +0100 (CET) Date: Sat, 16 Dec 2023 15:34:02 +0100 From: Lennart Poettering To: Nils Kattenbeck Cc: Eric Curtin , initramfs@vger.kernel.org, systemd-devel@lists.freedesktop.org, Stephen Smoogen , Yariv Rachmani , Douglas Landgraf Subject: Re: [RFC] initoverlayfs - a scalable initial filesystem Message-ID: References: Precedence: bulk X-Mailing-List: initramfs@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: On Do, 14.12.23 02:17, Nils Kattenbeck (nilskemail@gmail.com) wrote: > On Wed, Dec 13, 2023 at 10:03 AM Lennart Poettering > wrote: > > > > On Di, 12.12.23 23:01, Nils Kattenbeck (nilskemail@gmail.com) wrote: > > > > > > sysexts are erofs or squashfs file systems with verity backing. Only > > > > the sectors you access are decompressed. > > > > > > Okay I forgot that they were erofs based and mentioned cpio archives > > > so I assumed they would be one. > > > Do they need to be fully read from disk to generate the cpio archive? > > > > erofs is a file system, cpio is a serialized archive. Two different > > things. The discussion here is whether to pass the initrd to the > > kernel as one or the other. But noone is suggesting to convert one to > > the other at boot time. > > I was referring to the following line from sd-stub's man page: "The > following resources are passed as initrd cpio archives to the booted > kernel: [...] /.extra/sysext/*.raw [...]". I assume the initrd > containing the sysexts has to be created at some point? These cpios are created on-the-fly and placed into memory and passed to the invoked kernel. And yes, for that the data they contian needs to be read off disk first. Lennart -- Lennart Poettering, Berlin