[OLPC-devel] LinuxBIOS sometimes hangs after "Jumping to LinuxBIOS" (trac 53)

[Jim Gettys]

On Sat, 2006-08-26 at 00:08 -0700, Mitch Bradley wrote:

> >   3) after following the directions to install an image to flash
> > (uneventfully), the board I used will no longer boot anything; Samat saw
> > this problem a couple weeks ago and again tonight, but no one else had
> > reproduced it until I did.
> Actually, I had that problem last week, but I misinterpreted it as being 
> related to USB devices, because
> last week's occurrence went away the next day after I fiddled with the 
> USB devices.  But it happened to me again
> this Thursday night.  I turned off the board and switched to a different 
> board.  The next day, I tried the
> "bad" board and it worked.

Yup.  Extended powering off clears the problem.  Unplugging both
machines at OLPC for 20-30 minutes cleared the problem on both.

> > The machine says "Jumping to LinuxBIOS" on
> > the serial port and then does nothing.  Samat has seen this problem on a
> > different board tonight as well; it started working again after being
> > unplugged for a while (20 minutes). This smells like an uninitialized
> > register in the NAND flash,
> I have never knowingly used the NAND flash, so I question whether it's 
> related to that.
> 
> I have added a trac ticket describing my experiences with this problem.  
> When other people see it,
> please update the ticket with detailed information concerning what you 
> were doing.  Perhaps enough
> such reports will give us a clue where to look.

Thanks.

Note that this machine also magically recovered after being unplugged
for an extended period.

> > or some such problem. Not a blocker to a
> > release, as we can tell people not to install onto NAND until we find
> > and fix it.
> >   4) the current sugar in build 79 looks to not scale itself properly to
> > the 1024x768 resolution screen I chose for the default since that is the
> > most likely to "just work on everyone's screen" size.
> >
> > On the good side:
> >   o We have installation directions, that are now pretty good.  Whether
> > they are good enough for non-native speakers of English to follow is not
> > yet known.
> >   
> Now that the USB key image is hundreds of megabytes instead of 5, the 
> save/overwrite/restore aspect
> of the installation procedure is no longer a good idea.

Good point.

We should remove those from the directions.  Please go ahead.
                                          - Jim


-- 
Jim Gettys
One Laptop Per Child