Architectures/ARM/Fedora15 HardFP Bootstrap Virtual FAD 20110610

[ARM] Fedora15 HardFP Bootstrap Virtual FAD - 2011/06/10
We wish to accelerate the bringup of Fedora 15 on ARMv7 systems running with hardware floating point (hardfp). To that end, it is proposed to have semi-regular bootstrap days, during which we will meet in a virtual capacity (on IRC, and over the phone) to build up through cross-compilation (and other means) the core packages required for Fedora 15 to become self-hosting on ARMv7 with hardware floating point.

When and Where
14:00 UTC, Friday June 10th 2011

IRC: #fedora-arm on irc.freenode.net

Phone: We used a temporary bridge

Etherpad: http://www.tinyurl.com/fedora-arm (including full list of international dialin numbers)

Event owners

 * Jon Masters
 * Chris Tyler

Attendees

 * Jon Masters
 * Chris Tyler
 * DJ
 * Anthony Boccia
 * Salman Zafar
 * Jon Chiappetta
 * Paul Whalen
 * Dennis Gilmore
 * Brendan Conoboy
 * Russ Herrold
 * Peter Robinson

Summary
NOTE: Procedure for joining in with this post-activity day is documented on Architectures/ARM/Fedora15 HardFP Bootstrap


 * We kicked off with a discussion around build flags and confirmed the current plans
 * Building with a Cortex-A8 optimized, hardfp target (aapcs, vfpv3-d16), no NEON, no Thumb2
 * We may rebuild with different core optimizations in the future, may enable Thumb2
 * Probably will not worry about NEON initially
 * We reviewed various build dependencies we had available
 * Determined that tools for graphing and obtaining this stuff need improving
 * DJ provided an updated depsolving tool later in the day that was helpful
 * An initial attempt at a list of dependencies for RPM is in Etherpad
 * Determined we want to bring up rpm (rpm-build) at this stage
 * We determined a workflow based around a rootfs image in git
 * http://git.fedorahosted.org/git/arm.git (ssh://git.fedorahosted.org/git/arm.git) - see the "armv7hl" branch on that repo
 * Based on DJ's git://fedorapeople.org/~djdelorie/bootstrap.git (output from a run of stage1/stage used as seed)
 * Individual people/groups to create branches named armv7hl-NAME and request merge on list (Jon Masters maintaining)
 * Each person/group picks a package at a time to bootstrap (edit the Etherpad to add your package status before/during/after - including changing the list of remaining packages/done packages)
 * Collaboratively edit stage2/stage2 (copy of version in bootstrap, to be synced back later)
 * Explode out new package rpmbuild bits into stage2/rpmbuild before/after adding rule to stage2/stage2
 * Packages build in stage2/builds and are installed to the git repo rootfs under a chroot
 * Mount this rootfs git repo and chroot on target, run /stage2/stage2 TARGET (where TARGET is e.g. "db4", "readline", etc.)
 * Ensure general rules are present in stage2 script in the "go" sections to call targets in order
 * Later will verify the bootstrap scripts still run, but use this rootfs git approach to speed up bootstrap
 * Contribution will continue to this repo - post pull requests/push to armv7hl-NAME branch
 * We added more than a dozen bootstrap packages but more importantly worked out a workflow/model going forward
 * Continue this effort and repeat the activity day.
 * PROPOSAL: Next activity day on Wednesday June 22.

Program

 * Summarize requirements/sync up on build flags
 * Build for Cortex A-8, with AAPCS, and hard float (vfpv3-d16, not -d32)
 * Do not enable NEON (can add later)
 * Do not enable Thumb2 (confirmed can non-disruptively enable per-package later)
 * Current status of works in progress (DJ/Dennis/Seneca(?)?)
 * Plan will be to use DJ's bootstrap.git as a starting point
 * Extend stage2 script to on-target build up dependencies for rpm-build
 * Stash archives of populated build directories/bits on scotland.proximity.on.ca/fedora-arm/f15hardfp/bootstrap/
 * Minimal dependency discussion for F15
 * Plan to build dependencies required from the dependency graph
 * F15 x86_64 rpm-build dependency graph generated from Koji build dependencies
 * Plan for building/co-ordinating builds
 * Follow instructions for setting up DJ's bootstrap script and minimal rootfs (target chroot)
 * Grab a few package dependencies and work on them (add support to stage2 script)
 * Tar up the resulting build tree and make them available to others
 * Others install build tree ("make install") on their rootfs
 * Once sufficient deps are done for rpm, rebuild things as RPMs
 * host bits on scotland.proximity.on.ca/fedora-arm/f15hardfp/bootstrap/
 * Stage a Koji F15 instance with the working RPMs
 * Status before end of day
 * Plan for followup

Requirements

 * Internet connection to log into IRC, and phone if possible (phone not essential)
 * A supported ARMv7 target board
 * Lots of coffee

Setup

 * A pre-requisite is a working ARMv7-compatible supported target board, such as a BeagleBoard or a PandaBoard.
 * You can find out more from the main Fedora ARM pages about obtaining a pre-built rootfs (no installer yet)
 * We now have some Fedora ARM kernel packages for OMAP-based boards


 * Bootstrap will involve using a partially completed rootfs image that will be used inside a chroot
 * Since the new "arch" (armv7hl) is supported by ARMv7 kernels we can use a chroot trick
 * A complete from-scratch new arch port would need an also bootable rootfs (but it's not quite that)
 * Your normal target rootfs will be the stock F-13 rootfs in this case (so boot target as normal, then use chroot)
 * Fetch DJ's bootstrap.git repository
 * You will be making changes to the stage2 script (a copy of it in your rootfs)
 * Post patches and pull requests during the day for new packages
 * Fetch the partially bootstrapped rootfs (progress to date, built using bootstrap scripts)
 * Extract the root filesystem into a new directory and copy over to your board
 * Or mount over NFS from a server system (e.g. export /data/work/arm/bootstrap/f15/20110610/rootfs from a server to your board)
 * Optionally bind mount a directory within the rootfs (e.g. on an NFS server mount -o bind /data/work /data/work/arm/bootstrap/f15/20110610/rootfs/data/work) to allow you to get at data outside the chroot if you want to stash builds somewhere
 * Chroot into the new target rootfs
 * chroot /data/work/arm/bootstrap/f15/20110610/rootfs (or wherever you extracted it)
 * Take a look at the /stage2/stage2 script
 * Run it with a "module" name to build a particular package
 * /stage2/stage2 nspr
 * Modify the stage2 script to support building additional packages in the target rootfs
 * Post patches and git pull requests to the Fedora ARM mailing list ([mailto:arm@lists.fedoraproject.org arm@lists.fedoraproject.org]) (the stage2 script is kept in the bootstrap.git and a copy is in the rootfs)
 * Once sufficient packages are bootstrapped to support rpm, rebuild packages using RPM
 * Further dialog on package build deps and next steps