XO-1.5 users: need your SD card data

Peter Robinson pbrobinson at gmail.com
Thu Apr 14 12:36:15 EDT 2011

On Thu, Apr 14, 2011 at 5:26 PM, Daniel Drake <dsd at laptop.org> wrote:
> Hi,
> I may have found a way to make fs-update run on steroids. But I need
> to know if all/most SD cards are like mine.
> Please open your XO-1.5 and run:
> cat /sys/devices/pci0000:00/0000:00:0c.0/mmc_host/mmc2/mmc2:*/scr
> And post the output here.
> Please state clearly if this is a SD card that you installed yourself,
> or if its the one that was shipped in the laptop by default from OLPC.
> The optimization I'm looking at is that fs-update first erases the
> disk (which only takes a split second) and then spends most of its
> time writing zeroes, but for some SD cards (hopefully most of them),
> erasing the disk zeroes out the whole thing anyway. So no need to
> spend loads of time writing zeroes.

Do you want that sort of data just for the SD cards used specifically
in the XO. I have around 20 cards used for various linux hosts and I
can give you the info for them all if its useful.

Also generally writing zeros to any flash memory that implements its
own wear levelling algorithms I would have though wouldn't be of much


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