The sunxi u-boot driver supports the following video-mode options:
-- monitor=[none|dvi|hdmi|lcd] - Select the video output to use
+- monitor=[none|dvi|hdmi|lcd|vga|composite-*] - Select the video output to use
none: Disable video output.
dvi/hdmi: Selects output over the hdmi connector with dvi resp. hdmi output
format, if edid is used the format is automatically selected.
lcd: Selects video output to a LCD screen.
- vga: Selects bideo output over the VGA connector.
+ vga: Selects video output over the VGA connector.
+ composite-pal/composite-ntsc/composite-pal-m/composite-pal-nc:
+ Selects composite video output, note the specified resolution is
+ ignored with composite video output.
Defaults to monitor=dvi.
- hpd=[0|1] - Enable use of the hdmi HotPlug Detect feature
overrides the xres, yres and refresh from the video-mode env. variable.
Defaults to edid=1.
+- overscan_x/overscan_y=<int> - Set x/y overscan value
+ This configures a black border on the left and right resp. top and bottom
+ to deal with overscanning displays. Defaults to overscan_x=32 and
+ overscan_y=20 for composite monitors, 0 for other monitors.
+
For example to always use the hdmi connector, even if no cable is inserted,
using edid info when available and otherwise initalizing it at 1024x768@60Hz,
use: "setenv video-mode sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=1".