Dvfs; Display - VIA Technologies VAB-950 Quick Start Manual

VIA VAB-950 Yocto 2.6 EVK Quick Start Guide

3.4 DVFS

To verify the DVFS (Dynamic Voltage Frequency Scaling) function and list all the supported features, use the
following commands:
root@aiv8385-linux:~# ls –al /sys/devices/system/cpu/cpu0/cpufreq/
total 0
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 affected_cpus
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 cpuinfo_cur_freq
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 cpuinfo_max_freq
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 cpuinfo_min_freq
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 cpuinfo_transition_latency
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 related_cpus
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_available_frequencies
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_available_governors
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_cur_freq
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_driver
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_governor
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_max_freq
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_min_freq
-rwxr-xr-x 1 root root 4096 Dec 31 10:21 scaling_setspeed
drwxr-xr-x 2 root root 0 Dec 31 10:21 stats
To check the supported and current CPU frequency, use the following commands:
:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
1989000 1924000 1846000 1781000 1716000 1677000 1625000 1586000 1508000 1417000 1326000
1248000 1131000 1014000 910000 793000
:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
793000

3.5 Display

The VIA VAB-950 supports a choice of HDMI and LCD Panel display devices. To set the display device, first
connect the Windows 10 host machine and the VIA VAB-950 through the Micro USB 2.0 port using the Micro
USB cable.
Then set the two OS image jumpers (J7 and J5) to the download mode.
Press and hold the SW3 button. Then plug in the AC-to-DC power adapter to power on the VIA VAB-950.
Make sure there is a "fastboot: processing commands" message in the debug console. Then release the SW3
button.
Next, run the cmd.exe on your Windows10 host machine.
Use the fastboot.exe from the \Firmware\ folder to set the display device by using the following commands:
C:\>fastboot.exe oem display dsi
C:\>fastboot.exe oem display hdmi
Use the following command to check the current display device. In this example below, the current display
device is LCD panel output.
C:\>fastboot.exe getvar all
(bootloader) display: dsi
(bootloader) max-download-size: 0x4000000
(bootloader) version: 0.5
all: Done!!
Finished. Total time: 0.002s
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