#1574 HIGH BTest-4: sugar activities not working well when low power

Mitch Bradley wmb at firmworks.com
Wed May 30 15:26:45 EDT 2007

You can downgrade the operating system without downgrading the 
firmware.  Instructions:

a) Download the 385 NAND image file from


b) Copy that file onto a USB FLASH key, changing the name to 
"nand385.img".  Put it in the top-level (root) directory to save 
typing.  It is best to use an ordinary FAT-formatted key, but you can 
use a key with an ext2/3 filesystem if you are careful.

c) Insert the USB FLASH key into the OLPC and boot to the ok prompt (hit 
the Esc key during the countdown).

d) Type:
  ok  copy-nand u:\nand385.img

e) When that finishes, remove the USB FLASH key and power-cycle.

f) The system will boot almost normally, but X and sugar will not start 
properly.  The reason is because the system configuration script  is 
confused by the firmware name that starts with "q2c" instead of "q2b".  
That is easy to work around, though.

g) You will see a login screen that will flash every few seconds.  Wait 
for it to flash, then when it comes back to the login prompt, quickly 
type "root<enter>".  You should get a shell prompt.

h) Wait for it to flash again, and quickly type "killall 
prefdm<enter>".  That should stop the flashing.

i) Do this:
    cd /usr/sbin
    mv  olpc-bios-sig  olpc-bios-sig-
    ln -s  /bin/true  olpc-bios-sig

The system will work thereafter.

John Watlington wrote:
> Carla,
>     While this is theoretically very easy to do (a single command
> from open firmware), I believe you have encountered a problem with
> our release process.
> If you downgrade to build 385, it won't recognize the q2c11 firmware
> that was installed with build 406.  If you downgrade the firmware to
> one which will be recognized by that build, you loose the manufacturing
> data on the laptop.   The only way to go is forward.
> Perhaps this has changed.  Hopefully somebody else on devel can help.
> Thanks for the great job you've been doing,
> John
> On May 27, 2007, at 5:15 AM, Zarro Boogs per Child wrote:
>> #1574: sugar activities not working well when low power
>> --------------------- 
>> +------------------------------------------------------
>>   Reporter:  Carla   |       Owner:  dcbw
>>       Type:  defect  |      Status:  new
>>   Priority:  high    |   Milestone:  BTest-4
>>  Component:  sugar   |     Version:  Build 406
>> Resolution:          |    Keywords:
>>   Verified:  0       |
>> --------------------- 
>> +------------------------------------------------------
>> Comment (by Carla):
>>  More cases & different diagnostic:
>>  Two of them don't boot Sugar and one camera is behaving really  
>> strange,
>>  not displaying the camera input, and not saving at all (We already  
>> have
>>  some other camera cases, though in this case the battery was fully
>>  charged, and we also tried using the charger.) All these happened  
>> right
>>  after we re-imaged the XOs with the recent 406 image. We have  
>> B2s...is
>>  there a way to down-grade them?
>> -- 
>> Ticket URL: <http://dev.laptop.org/ticket/1574#comment:3>
>> One Laptop Per Child <http://laptop.org/>
> _______________________________________________
> Devel mailing list
> Devel at lists.laptop.org
> http://lists.laptop.org/listinfo/devel

More information about the Devel mailing list