Easiest way to compile 3.17/3.19 kernel

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You are trying to do this with mainline kernel? 3.19.x and up?

Those functions are not operational yet.

Yes, 3.19.7.  Thanks for the feedback on this.

You mentioned a few days ago about the onboard audio driver work going on.  Is there a forum I can follow that on?

Check here, it's quite updated.


Also, take a look on this thread.

OK, there are a couple of issues to reply to:

1) @tkaiser:
I would search the forum for "/sys/devices/system/cpu/cpu0/cpufreq", "/sys/devices/platform/sunxi-i2c.0/i2c-0/0-0034/temp1_input" or even "bpi-monitor.tgz" to get a clue how to readout the actual CPU frequency as well as the PMU's and SoC's temperature.

Reading out the temperature doesn't work this way in the mainline kernel. But there is a way of reading out one of the two temperature sensors in mainline (the one embedded in the touchscreen controller in the SOC), at least starting from kernel 4.0:
  1. cat /sys/devices/virtual/thermal/thermal_zone0/temp
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Btw.: This is also the temperature that the cpufreq driver (introduced in kernel 4.0) uses for thermal throttling.

For the second temperature sensor (in the PMU) there is a patch by Correntin Labbe, available on his site:
http://sunxi.montjoie.ovh/ (scroll to the bottom)

2) @tkaiser:
Adjusting CPU frequency works in steps of 48MHz and will always be rounded down...

Be aware, that is only true for kernels older than 4.0. With the cpufreq driver, you are limited to a set of operating points defined in the device tree (as of version 4.0, these operating points are 960, 912, 864, 720, 528, 312 and 144MHz). So, while for example 600MHz would work on older kernels, with kernel 4.0 cpufreq will fall back to 528MHz if you try to set 600MHz.

3) @igorpecovnik:
  1. at my system:
  2. current policy: frequency should be within 480 MHz and 960 MHz.
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Is your 3.19.x image patched in any way? Because the mainline 3.19 kernel doesn't support cpufreq. This was added in kernel 4.0.

4) markwinger:
If you want to set the cpu frequency yourself and read out the temperature, you should go with kernel 4.0.



Is your 3.19.x image patched in any way? Because the mainline 3.19 kernel doesn't support cpufreq. This was added in kernel 4.0.

No, it was misunderstanding. I was talking for kernel 3.4.

Hey Igor,

I asked this before but you haven't answered yet.  Have you considered building a kernel for the odroid-c1?  I could use the faster/extra cores.  I'm willing to try but I don't know how to get the hardware specifics needed.


Edited by igorpec at Tue May 12, 2015 21:06

No, I am now working with Odroid and not planning to. Out of resources

I understatnd.  Thanks.

Edited by silentcreek at Tue May 12, 2015 21:45

If you are looking for a board with more cores and power, take a look at orange pi plus with an Allwinner H3 chip. Work to support it in mainline is already being done - so it's very likely that support for that chip will land in the official kernel before Hardkernel manages something similar for their Odroid C-1. And who knows... maybe if H3 goes upstream, Igor will have an image for that, too ;)

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