Tegra TK1 board- setting frequency for the CPU core during boottime time


Currently I am working on an embedded project using Nvidia’s Tegra TK1 - jetson board.
The objective is to have the shortest boot time possible to run the weston video for linux application.

After startup I am checking the frequency of the cpu cores,
root@jetsontk1:~# cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq
root@jetsontk1:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
root@jetsontk1:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

root@jetsontk1:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_gov
ondemand performance
root@jetsontk1:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

204 MHz seems to be low. I understand that the frequency depends on the governor settings and on the run levels to optimize the power.
During startup, I wish to run the CPU having full performance to have fast boot time. May I know how and where can I set the frequency for the cpu cores, my basic understanding is that I need to add it to the device tree file. Can you please give your suggestions for the topic?

Mit freundlichen Grüßen / Thanks & Regards,
Vinothkumar Eswaran

The script which kicks in scaling during boot can be disabled. After that what you put in rc.local should stick:

sudo update-rc.d -f ondemand remove


Thanks for your reply, but I am looking for options that I can setup during boot time.

My objective is to have the shortest boot time possible. So during startup of kernel, driver and file system initialization I wish to have CPU running at its maximum speed.

The “ondemand” changes boot time scripts. With ondemand in place anything you do for performance will probably get countermanded by init. So…to do what you want, and if what you want includes improving performance mode without care for preserving power consumption, then you do want to disable ondemand. Then you can set performance mode in rc.local, or even modify init if you really need to. The other URL mentions commands to force performance mode. Plus:

Since this is essentially desktop Ubuntu you can tune and change packages (such as removing unneeded packages) as per any Ubuntu administrator’s type manual. One thing I would suggest is that if you do not need DHCP network setup, then you should use a static address assignment instead to avoid DHCP query time.