FreeBSD on Cubieboard 2, UDOO and Galaxy Note 10.1 (Exynos).

Tim Kientzle kientzle at freebsd.org
Fri Sep 27 02:43:49 UTC 2013


On Sep 26, 2013, at 3:31 PM, Bernd Walter <ticso at cicely7.cicely.de> wrote:

> I also noted that the Beaglebone Black seems to run at 550MHz only.
> I've found out from NetBSD mailinglist, that the PLL must be
> reprogrammed for higer frequency and the core voltage needs adjustment
> too.
> Of those 3 boards the BBB was the only board mention CPU frequency at all.

I've not looked into the code required, but I know some of the issues:

* For the older "white" Beaglebone, at least, the CPU frequency
   needs to be set properly depending on the power supply.  So
   "someone" needs to read the PMIC and determine whether
   power is coming from the 5V input or from USB.  In the latter
   case, I believe the lower frequency may be appropriate.

* For BB White, I believe the "someone" was U-Boot; the FreeBSD
  kernel just assumed the CPU was already properly initialized.
  I haven't looked to see if the U-Boot we're using now does power
  config for BBB.

* We should add a PMIC driver and do this setting in our kernel.

Tim



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