opensource@seneca

Sugar on a Stick is a project which aims to create a live learning environment on a USB stick. This environment is a Fedora spin hosting the Sugar environment (the learning software original created as part of the OLPC project).

In previous versions of SoaS, the activities were not thoroughly screened before inclusion in the Spin, and so the SoaS Activity Criteria were introduced. I've been working with some other POSSE RIT participants to try and get three activities - Abacus, Maze, and Memorize - to the point of meeting the criteria. It's been a frustrating experience, but we've made some progress:

• Abacus
• Performed a package review (not passed, but close) of Peter Robinson's sugar-abacus package in Fedora
• Created a basic page for recording smoke test results
• Maze
• Filed a bug against the sugar-maze package in Fedora (apparently missing an essential .py file)
• Memorize
• This activity meets most of the criteria, but we weren't able to save to the journal (know issue) and could not confirm that collaboration works (might have been our Sugar configuration or networking)

It's apparent that the Sugar project needs more contributions, including wiki gardening, testing, and documentation -- all of which are areas in which new contributors can become quickly involved.

Mozilla uses CentOS for their Linux builders. They have up to this point also been running their unit tests on CentOS, but Armen has now switched the Linux unit tests over to 32- and 64-bit Fedora. This is a great win, because it means that Firefox will be tested against a more-current environment.

One interesting find I made while working with the Seneca students on Fedora ARM was that a loopback filesystem hosted on top of an NFS share can outperform the NFS share. Yes, it's counter-intuitive, because that would seem to introduce additional layers of processing, but I think it makes sense.

When using NFS, file metadata management is performed by NFS. When loopback-mounting a filesystem in a file hosted on NFS, the file metadata management takes place entirely on the local system -- NFS merely provides a data store. In this sense, it's not much different from iSCS, because the loopback filesystem can't be readily accessed by two separate hosts at once.

In fact, on a small ARM system such as an OpenRD-Client, loopback-ext3-on-NFS over GigE handily outperforms both Class 6 SD and a local USB-PATA drive.

Why not just use iSCSI? Well, for reasons I haven't yet determined, the Fedora iSCSI initiator doesn't work reliably on ARM-- under heavy load, it sends invalid opcodes to the target. This sounds like an alignment issue, but alignment fixups don't cure it. Investigation continues...

ARM processors power the digital mobile age. Billions are produced per year, ending up in the majority of cellphones as well as in e-book readers, plug computers, the OLPC XO 1.75, tablets, netbooks, intelligent RJ-45 network jacks, and even microSD cards.

The Fedora ARM Secondary Architecture project has done a great job of porting Fedora releases to ARM. To assist this initiative, this semester's Software Build and Release course at Seneca (SBR600) put together a new Koji build farm for the ARM architecture in preparation for using koji-shadow to follow the primary architectures. It's been a fascinating and challenging project -- working with cross-compilers, emulators, and hardware with much smaller configurations than standard PCs. A large amount of effort was spent benchmarking various configurations to determine optimal memory and storage arrangements and to compare emulated vs. hardware ARM performance to guide the configuration of the build farm.

So now we're at the end of the semester. Where do things stand?

• We have a working Koji build system, with two hardware builders plus emulated (VM) builders
• Since we're at the end of the semester, things will be quiet for the next week and a half, but then we've hired a graduate to work on this full-time (intros coming up shortly )

What's next? In May-June we expect to:

• set up FAS2 certs
• add 10+ hardware builders
• implement koji-shadow

The Fedora qemu-system-arm package provides pretty good ARM processor emulation, which can be used to run the Fedora ARM secondary architechture. This is an easy way to get started working with ARM -- for example, while waiting for your plugcomputer, beagleboard, or OLPC XO 1.75 to arrive

The previous wiki notes on using ARM with QEMU didn't cover using qemu-system-arm under libvirt management. This meant that you couldn't easily take advantage of libvirt benefits such as automatic network setup (with DHCP and NAT), the virt-manager GUI tool, guest autostart, or disconnection/reconnection to the console.

I've updated https://fedoraproject.org/wiki/Architectures/ARM/HowToQemu to include some basic notes on setting this up, and provided some files to simplify and speed up the process. Jump in and join Fedora-ARM, the water's nice!

mock is a Fedora package building tool. When invoked to build a specific package from a source RPM (which contains the package source plus a spec file), it creates a chroot environment, populates that environment with a very small set of base packages plus the build requirements specified in the spec file, and then attempts to build the package in that environment. This permits the build environment to be (somewhat) isolated from the host environment, so that a different set of build dependencies (tools, libraries, and headers) can be used for building. It's ideal for proving that the build requirements are correct, and it also permits you to build a large set of packages without installing a lot of build dependencies on the host system. It's also a highly automated and very convenient way to build

I've been experimenting with building for and on the ARM architecture. Fedora 12's mock package does not include a config file for ARM; here is a config file I've cobbled together as a starting point:

config_opts['root'] = 'fedora-12-arm'
config_opts['target_arch'] = 'armv5tel'

# The chroot_setup_cmd is usually 'groupinstall buildsys-build' but that hasn't been defined for ARM yet.
# Instead, the package list is specified here.
config_opts['chroot_setup_cmd'] = 'install bash bzip2 coreutils cpio diffutils fedora-release findutils gawk gcc gcc-c++ grep gzip info make patch redhat-rpm-config

rpm-build sed shadow-utils tar unzip util-linux-ng which bash curl cvs fedora-release gnupg make redhat-rpm-config rpm-build shadow-utils'
config_opts['dist'] = 'fc12'  # only useful for --resultdir variable subst

config_opts['yum.conf'] = """
[main]
cachedir=/var/cache/yum
debuglevel=1
reposdir=/dev/null
logfile=/var/log/yum.log
retries=20
obsoletes=1
gpgcheck=0
assumeyes=1

# repos

[fedora]
name=fedora
mirrorlist=http://mirrorlist.fedora-arm.wantstofly.org/?repo=fedora-12&arch=arm
failovermethod=priority

[updates-released]
name=updates
mirrorlist=http://mirrorlist.fedora-arm.wantstofly.org/?repo=updates-released-f12&arch=arm
failovermethod=priority
"""

This uses the existing fedora-arm repositories along with an explicit list of base packages for the mock environment. Ultimately, the buildsys-build package group will be specified in a special-purpose repository, but the explicit package list given here provides a good starting point.

Update: here's a link to this mock config file: http://cdot.senecac.on.ca/arm/fedora-12-arm.cfg