From owner-freebsd-arm@freebsd.org Thu Nov 2 01:10:53 2017 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4A0B2E6819B for ; Thu, 2 Nov 2017 01:10:53 +0000 (UTC) (envelope-from fbsd@www.zefox.net) Received: from www.zefox.net (www.zefox.net [69.239.235.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "www.zefox.org", Issuer "www.zefox.org" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 103F564A0B for ; Thu, 2 Nov 2017 01:10:52 +0000 (UTC) (envelope-from fbsd@www.zefox.net) Received: from www.zefox.net (localhost [127.0.0.1]) by www.zefox.net (8.15.2/8.15.2) with ESMTPS id vA21B1UX066368 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 1 Nov 2017 18:11:01 -0700 (PDT) (envelope-from fbsd@www.zefox.net) Received: (from fbsd@localhost) by www.zefox.net (8.15.2/8.15.2/Submit) id vA21B09G066367; Wed, 1 Nov 2017 18:11:00 -0700 (PDT) (envelope-from fbsd) Date: Wed, 1 Nov 2017 18:11:00 -0700 From: bob prohaska To: Mark Millard Cc: Carl Johnson , freebsd-arm@freebsd.org, bob prohaska Subject: Re: RPi2 snapshot for armv7 won't boot. Message-ID: <20171102011100.GB66048@www.zefox.net> References: <86fu9xmx3u.fsf@elm.localnet> <20171101231700.GA66048@www.zefox.net> <497A9769-0BEF-4B2A-B0C8-0CA399F4DA29@dsl-only.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <497A9769-0BEF-4B2A-B0C8-0CA399F4DA29@dsl-only.net> User-Agent: Mutt/1.5.24 (2015-08-30) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Nov 2017 01:10:53 -0000 On Wed, Nov 01, 2017 at 05:27:52PM -0700, Mark Millard wrote: > > [Sometime between -r324743 and -r325156 armv7 > has been broken such that /sbin/init fails, > apparently no matter how the build is done. > I'm ignoring that issue here.] > I've never come close to getting far enough for init to be an issue. Something has always stopped buildworld, or at least interfered enough to stop installworld. > > Crochet has one major configuration problem for > reliability when swapping is to be involved on > the target: Crochet creates a context using a > swapfile instead of using a swap partition. > At least on 11-stable the swap file was enough for buildworld/kernel, though I don't know how thin the margin is. That particular host doesn't get fiddled with much, so long as it works. > See bugzilla 206048 about the swapfile issue. > > An RPI2 self-hosted likely(?) swaps extensively at > times. ("Only" 1 GiByte of RAM but clang is built, > for example.) I expect that having swap space is a > requirement to have self-hosting work. I'm not > familiar with what a near-minimal size might be. > The box I'm trying to get from v6 to v7 uses a dedicated swap partition on a usb-flash drive. Highest swap usage I've noticed is a little under 1GB out of 2GB total. > I'm not claiming this explains what you might be > seeing. But the use of swapfiles is a known > problem, apparently known long before that bugzilla > submittal was made (2016-Jan-08). > The first problem encounted was fixed per you, simply hardcoding the result of uname -p (=armv7) in Makefile.inc1. Off and on, there were pmap faults (pt2map abort) which superficially resemble what you reported about a year ago. At first, they went away spontaneously, then returned (always late in buildworld). A single-user buildworld succeeded, but installworld reported a strip error in clang and clang was never updated. Seemingly most else was updated. At this point installworld is failing very quickly in /usr/src/rescue, so I'm trying again to do a clean kernel, world, install cycle. > My experience has lead me to always use swap > partitions --and never swap files. > Agreed entirely. > > Another issue is significant swapping activity is > likely not a good match to most sdcards. For this > class of devices, I normally configure causing the > root file system and swap space to be on a USB > drive, such as a USB SSD. So mostly it is the > kernel and earlier stages that come from the > sdcard and the sdcard is otherwise little used > in normal operation. > So far, I've gotten away with leaving / on the microSD card and (most) everything else on a USB flash drive. I'm rather curious to see if I can wear either one out. So far, no. I'd be very encouraged to know if anyone at all is trying to self host -current on RPI2, in any configuration. Thanks for reading! bob prohaska