Add new image for ODROID-XU4/HC1/HC2

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Change-Id: I9beb3311ddf2be52614621ade037bfd17a2be5e8

install/odroidxu4/image.md

@@ -0,0 +1,14 @@
+# ODROID-XU4/HC1/HC2
+
+>:warning: The default account is 'odroid' and its password is 'odroid', please do change the password at the first boot.
+
+## Ubuntu 20.04
+* [20210111](http://ppa.linuxfactory.or.kr/images/raw/armhf/ubuntu-20.04-server-odroidxu4-20210111.img.xz) - Linux kernel v5.10
+
+### Please do this before flashing the image to eMMC
+* You need to replace the bootloader in the eMMC since the image can not boot from the Hardkernel stock U-boot, so please follow up the instructions.
+1. Download and flash the [update image](http://ppa.linuxfactory.or.kr/images/raw/armhf/update_uboot-odroidxu4-20210111.img.xz) to SD card.
+1. Attach your eMMC and SD card flash with the update image to your ODROID-XU4
+1. Place the boot select switch to SD card
+1. Power on, then update will start and turn off once the update is finished
+1. Done

install/prebuilt_image.md

@@ -7,6 +7,7 @@ For this method, only server image is provided at the momenty while Hardkernel p
 * [ODROID-N2/N2Plus](odroidn2/image.md)
 * [ODROID-C4](odroidc4/image.md)
 * [ODROID-HC4](odroidhc4/image.md)
+* [ODROID-XU4/HC1/HC2](odroidxu4/image.md)
 
 ## See also
 * [Balena Etcher](https://www.balena.io/etcher/)