Utilite: Android: Operating instructions
From Utilite Wiki
Most Utilite supported features are operated using normal Android controls.
This page contains information about features and services, which are less straight-forward to operate, or are less widely known.
By default Utilite is configured to use HDMI display with 1080p resolution.
This setting can be overridden by providing alternate boot arguments to the Android/Linux kernel.
- Connect to the serial console as explained in the Development section.
- Press ENTER to stop the countdown.
setenv videomode video=mxcfb0:dev=hdmi,if=RGB24,1920x1080M@60 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off # default video mode (HDMI) setenv videomode video=mxcfb0:dev=dvi,if=RGB24,1920x1080M@60 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off # DVI display with 1080p resolution setenv videomode video=mxcfb0:dev=dvi,if=RGB24,1280x1024M@60 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off # DVI display with 1280x1024 resolution
- Type in boot to proceed to kernel boot overriding default video mode.
Handling memory shortage
Devices with small amount of physical memory (~512MB) might experience memory shortage expressed by system processes being killed and restarted repeatedly, resulting in performance lag.
In this case, freeing up some memory reserved for graphics sub-system might turn out useful, e.g. by degrading screen resolution to 720p and lowering GPU-reserved memory below default 192MB, by appropriately setting videomode bootloader variable:
setenv videomode video=mxcfb0:dev=hdmi,if=RGB24,1280x720M@60 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off gpumem=64M
Accessing Bootloader Variables from Android
Utilite Android is packed with fw_printenv and fw_setenv u-boot tools, that allow viewing and setting U-Boot environment variables from Android, as opposed to U-Boot console.
For instance, display configuration settings could be overridden from Android:
- Connect ADB to Utilite
- On PC workstation, issue
$ adb root
|In case ADB is connected via USB, detach / re-attach USB cable.|
- Display videomode setting
$ adb shell fw_printenv videomode
- Set videomode to DVI
$ adb shell fw_setenv videomode video=mxcfb0:dev=dvi,if=RGB24,1920x1080M@60 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off
- Reboot Utilite
Automatic suspend when inactive
By default, Utilite is configured to stay awake while connected to the power.
In order to change this behavior, proceed to Settings->Developer options, uncheck Stay awake ... while charging to enable the device going to suspended state.
|If Developer options item is hidden, re-introduce it proceeding to Settings->About tablet and clicking on Build number 7 times consequently.|
Utilite Android package permits full root access.
The su utility will switch a user to root not requiring any credentials or password.
In order to harden system security one might replace su implementation or remove it altogether.
/system/etc/install-recovery.sh script is run upon system boot by Android init process.
As system partition is mounted 'read-only', one should remount system 'rw', prior to attempting to edit the script.
Normal Android behavior is to prioritize network interfaces (in descend order):
- 3G [not supported]
Whenever higher-priority network interface is available, the lower-priority interfaces will be torn down.
Audio sink selection
Utilite may use either one of the following audio devices:
- HDMI - default when HDMI video is selected, and totally inaccessible otherwise
- analog - default when DVI video is selected
Audio sink selection should be done with a designated application, e.g. SoundAbout, available via Google Play Store.
|audio device||sink name|
|HDMI||Aux Digital (HDMI)|
|If after making the selection with SoundAbout nothing happens, restart the application.|