Playing with my Orange Pi Mini board, (using a DVI/HDMI conector) the monitor was unable to display the original 1280×720 resolution, cutting the image. I couldn’t get the monitor’s maximum resolution (1680×1050) yet, but managed to configure the boot environment variables to set up a 1280×1024, which worked OK (at least it shows all the text).
In the boot partition (on bananian 15.01, it was /dev/mmcblk0p1), you must edit the uEnv.txt file. You should find something similar to:
...
bootargs=console=ttyS0,115200 console=tty0 sunxi_g2d_mem_reserve=0 sunxi_ve_mem_reserve=0 disp.screen0_output_mode=EDID:1280x720p50 hdmi.audio=EDID:0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
...
and modify the disp.screen0_output_mode variable to the following:
...
bootargs=console=ttyS0,115200 console=tty0 sunxi_g2d_mem_reserve=0 sunxi_ve_mem_reserve=0 disp.screen0_output_mode=EDID:1280x1024p60 hdmi.audio=EDID:0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
...
Update:
There are some distros (such as Lubuntu and Debian) for Orange Pi where the correct bootarg variable to be changed is disp.screen1_output_mode instead.
In the case of Lubuntu, the uEnv.txt file is placed in another partition (/dev/mmcblk0p1). You can just mount it somewhere:
# mount /dev/mmcblk0p1 /mnt
add the disp.screen1_output_mode definition to the bootargs:
# vi /mnt/uEnv.txt
# sync
# umount /mnt
and reboot to make the changes effective:
# reboot
For Debian, the bootargs definition is found in /boot/boot.cmd, and after modify it, you should recreate /boot/boot.scr file with the following:
# mkimage -C none -A arm -T script -d /boot/boot.cmd /boot/boot.scr
not too amused 