We need to check if the device still has the required kernel modules compiled in like mentioned in the bug #587.
Because of that, and because the vendor u-boot doesn't support the display, installing Parabola probably requires you to use the Serial console.
It's also pretty well supported by Linux (with some things lacking like 3D acceleration) but at the time of writing it's not supported by upstream u-boot (yet).
2 Using the stock vendor bootloader
The GTA04 typically has its bootloader in NAND. So there is no need to install a bootloader, however we might need to adjust the boot parameters/cmdline given to the kernel and the uboot environment to fit your partioning scheme. It is strongly advised to have a serial console working to do that as otherwise you won't be able to see why the device is not booting. Its uboot also expects an uImage in /boot/uImage. It can be created like that:
# pacman -S --needed uboot-tools # cat /boot/vmlinuz-linux-libre /boot/dtbs/linux-libre/omap3-gta04a3.dtb > /tmp/zImage.dtb # mkimage -A arm -O linux -T kernel -C none -a 0x82000000 -e 0x82000000 -d /tmp/zImage.dtb /boot/uImage