Weird behaviour

Kevin Gordon kgordon420 at
Sat Feb 18 16:33:12 EST 2012

On Tue, Feb 14, 2012 at 5:18 PM, James Cameron <quozl at> wrote:

> I agree, it seems likely to be a hardware problem with USB.
> You said file copy from USB to the filesystem was just as slow.  Is that
> using OpenFirmware or Linux?  I'm expecting you used Linux.


> We made some USB changes in OpenFirmware, but these ought not to have
> had this effect, and should have no effect at all on Linux.  Yet, I am
> interested to know what version of OpenFirmware is on the units.
> --
> For your interest, next time you need it, there's an OpenFirmware test
> feature for checking the fs-update transfer rates from USB.
> ok null-fsdisk fs-update u:\fs.zd
I did the following to try to establish a reference point on a perfectly
good XO 1.5 with functioning USB

I upgraded the firmware to Q3C01, which eliminated the write-block-start
and finish not unique messages.

However invoking the  command null-fsdisk fs-update u:\os883.zd4 (which is
the build we use on these machines and is teh file on the USB drive) gives
the following warnings on the good  (reference) XO 1.5:

Image size is larger than output device
file said highest block 29849 but wrote only as high as block 0
file did not write a zero block, but wrote only as low as block 29489

> What it does is read the data from USB and then discard it.  That way
> you can exclude the time otherwise spent writing to the internal microSD
> or eMMC.  The feature was recently fixed (10th Feb 2012) so use firmware
> after that date.  I didn't go back to find when it broke.
> --
> James Cameron
> _______________________________________________
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> Devel at
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