[Sugar-devel] USB stick advice

[Tomeu Vizoso]

On Tue, Apr 14, 2009 at 13:14, Caroline Meeks <solutiongrove at gmail.com> wrote:
>
>
> On Tue, Apr 14, 2009 at 4:16 AM, Tomeu Vizoso <tomeu at sugarlabs.org> wrote:
>>
>> [cc'ing fedora-olpc because we are using unmodified fedora tools]
>>
>> On Mon, Apr 13, 2009 at 23:33, Walter Bender <walter.bender at gmail.com>
>> wrote:
>> > Thanks. This is all helpful. I wonder what the Fedora USB Creator does
>> > when it runs under Windows?
>>
>> AFAIK, what Mitch says is what we currently do when using both
>> livecd-iso-to-disk.sh and the Fedora Live USB creator.
>>
>> For flashing a big number of sticks with a port replicator, we could
>> first use livecd-iso-to-disk.sh to copy the partition files to one
>> stick and set the bootable flag, then use dd to read into an image and
>> then dd again to write it to the rest of the sticks, provided they are
>> actually identical inside.
>
> I don't think they are actually identical inside. They show up as all
> different sizes.

Ouch, that's good to know.

Tomeu

> I used dd to make an image then zcat to write it to new sticks.
>
> zcat ./SoaS-Beta-4-9.img.Z > /dev/disk2
>
> I got a fairly high failure rate so I'm not saying this is a good method.
>
>>
>> Regards,
>>
>> Tomeu
>>
>> > -walter
>> >
>> > On Mon, Apr 13, 2009 at 3:53 PM, Mitch Bradley <wmb at laptop.org> wrote:
>> >> My first order recommendation is "don't use dd to blast an image over
>> >> the
>> >> existing partition map".
>> >>
>> >> The problem with doing so is that it wrecks the factory partition
>> >> layout.  I
>> >> strongly suspect that said factory layout is, on many sticks, optimized
>> >> for
>> >> the characteristics of the stick's internal firmware and the hardware
>> >> block
>> >> sizes of the NAND Flash chips.
>> >>
>> >> Unfortunately, the alternative is rather more complicated procedurally
>> >> than
>> >> "dd and pray".  But given the indifferent results from dd&pray, I think
>> >> it
>> >> may be worthwhile to go for a more elaborate procedure.
>> >>
>> >> Here is an outline of what I think really should be done:
>> >>
>> >> a) Ensure that your filesystem image is somewhat smaller than 1G (or 2G
>> >> or
>> >> whatever your base size) so it will fit on "all" 1G devices.
>> >>
>> >> b) The image is just the partition contents, excluding the partition
>> >> block
>> >> and master boot record.
>> >>
>> >> c) The installation procedure involves
>> >>
>> >> c1) Editing (not replacing) the existing partition map, setting the
>> >> first
>> >> partition's "boot flag" byte and changing its filesystem type to ext2
>> >> or
>> >> whatever.  (Ideally it would better not to change the filesystem type,
>> >> instead sticking with the factory FAT partition, but I understand what
>> >> a
>> >> hard nut that is to swallow for Linux enthusiasts.)
>> >>
>> >> c2) Copying the image into the partition
>> >>
>> >> c3) Installing your bootloader using an installation program instead of
>> >> dd,
>> >> thus replacing the first sector's Master Boot Record and doing whatever
>> >> else
>> >> is necessary to complete the bootloader's installation.  I have had the
>> >> best
>> >> results with syslinux.
>> >>
>> >> There is, of course, a chicken-and-egg problem of how do you run the
>> >> bootloader's installer.  On the other hand, you have the same problem
>> >> with
>> >> "dd" - in principle, on any machine that can run "dd", you can also run
>> >> syslinux.
>> >>
>> >> If you want to talk more about this issue, please feel free to keep the
>> >> conversation going.  It is a topic that has been much on mind recently.
>> >>
>> >> Mitch
>> >>
>> >>
>> >>
>> >> Walter Bender wrote:
>> >>>
>> >>> I was wondering if you have any words of wisdom to share with us re
>> >>> USB stick compatibility, given your experience with the XO. There
>> >>> seems to be a lot of variability in terms of which sticks boot which
>> >>> machines in our Sugar-on-a-Stick experiments, e.g., using the same
>> >>> machine (a Classmate running XP) to burn the same image (the Beta SoaS
>> >>> iso) onto USB storage media from three different vendors, I cannot
>> >>> predict which one(s) will be bootable on any particular piece of
>> >>> hardware. Is there any deterministic way to proceed, or is trail and
>> >>> error our only recourse?
>> >>>
>> >>> thanks.
>> >>>
>> >>> -walter
>> >>>
>> >>>
>> >>
>> >
>> >
>> >
>> > --
>> > Walter Bender
>> > Sugar Labs
>> > http://www.sugarlabs.org
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>> > Sugar-devel at lists.sugarlabs.org
>> > http://lists.sugarlabs.org/listinfo/sugar-devel
>> >
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>
>
>
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> Caroline Meeks
> Solution Grove
> Caroline at SolutionGrove.com
>
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