From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by mx.groups.io with SMTP id smtpd.web09.19986.1628761432072010876 for ; Thu, 12 Aug 2021 02:43:52 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: bootlin.com, ip: 217.70.183.198, mailfrom: alexandre.belloni@bootlin.com) Received: (Authenticated sender: alexandre.belloni@bootlin.com) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 1BDE2C0002; Thu, 12 Aug 2021 09:43:49 +0000 (UTC) Date: Thu, 12 Aug 2021 11:43:49 +0200 From: "Alexandre Belloni" To: "Robert P. J. Day" Cc: OE Core mailing list Subject: Re: [OE-core] issues with wic creating "multi-partition" images? Message-ID: References: <9dafcfda-fa85-8a7d-cd7e-6a584ac87c4d@crashcourse.ca> MIME-Version: 1.0 In-Reply-To: <9dafcfda-fa85-8a7d-cd7e-6a584ac87c4d@crashcourse.ca> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello, On 12/08/2021 05:26:47-0400, Robert P. J. Day wrote: > > asking from a position of massive ignorance since i just started > digging into wic, but i've been reliably assured that i am going to > encounter issues with trying to get wic to create what i choose to > call "multi-partition" images, and i just want to know if this is an > actual issue. > > current wic setup is to create an image which supports what i'll > call the "preserve" partition -- distinct partition to hold > non-upgradeable content; factory default firmware, non-volatile S/W > config settings, that sort of thing, that is meant to be preserved > across software upgrades. nothing unusual about this, strikes me as > pretty standard. > > now, any recipe in the current build is allowed to contribute its > own preserve data by adding it to a top-level "/preserve" directory. > that directory is added to the content of the base package: > > FILES_${PN} += "/preserve" > > and in the end, the wic image is responsible for taking everything > under /preserve in the final rootfs and installing it in the preserve > partition, wholly separate from however it installs the remainder of > the rootfs. > > does wic have a problem with doing this? it seems so straightforward > that i'm having trouble believing wic can't do it. thoughts? or > perhaps a link to some reference board or vendor that has a .wks file > that does exactly that? In your wks.in, you can simply do something like that: part / --source rootfs --fstype=ext4 --label root --exclude-path=preserve/ part /preserve --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/preserve --fstype=ext4 --label preserve -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com