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Revision as of 00:01, 9 January 2015 by Quozl (talk | contribs) (Created page with 'OLPC has begun enabling the second processor core in the XO-4 laptops. == Problem == The released operating systems 13.2.1 and 13.2.2 run only one core. The XO-4 under…')
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OLPC has begun enabling the second processor core in the XO-4 laptops.

Problem

The released operating systems 13.2.1 and 13.2.2 run only one core. The XO-4 underperforms compared to some other devices.

Solution

XO-4 only:

Upgrade to 14.1.0 once it is released

Workaround

On unsecure laptops running 13.2.0, 13.2.1 and 13.2.2, upgrade the kernel and the firmware at the same time. The exact steps are:

sudo rpm -U kernel-3.5.7_xo4-20150108.2115.olpc.b2c8f99.armv7hl.rpm
  • shutdown,
sudo poweroff
  • upgrade the firmware,
ok flash u:\q7c02.rom
  • allow the laptop to boot.

Reverting

sudo poweroff
  • downgrade the firmware,
ok flash u:\q7b43.rom
  • allow the laptop to boot.

Using a single core kernel on 14.1.0

Certain tasks may benefit from the higher memory bandwidth of the single core kernel.

  • download the 3.5.7_xo4-20141118.2329.olpc.cd558cf kernel package,
  • download the q7b43.rom old firmware,
  • copy both to a USB drive,
  • note: remove the /bootpart/boot/bootfw.zip file, to prevent automatic firmware upgrade,
  • downgrade the kernel,
  • shutdown,
sudo poweroff
  • downgrade the firmware,
ok flash u:\q7b43.rom
  • allow the laptop to boot.

See Also