NOTES

Odroid related stuffs

I have an old Odroid U3+ that is out of production and support. The last distro was Ubuntu 18.04. But, I was able to upgrade to Ubuntu 20.04, 22.04, and finally 24.04 and kernel 6.17.9.

---

1. Odroid as scriptable keyboard, mouse, and screen

---

Compiling kernel

USB Gadget driver works only with 4.16.x kernels (4.16.0 to 4.16.18). And, you need to recompile the kernel with USB Gadget modules. The process is the same as compiling for BeagleBone Black.

Generating uIintrd

First, build initrd.img as usual. Then, convert to uInitrd used by U-Boot.

export KR=4.16.0-odroid

mkinitramfs -o initrd.img-$KR  $KR
mkimage -A arm -O linux -T ramdisk -C none -n "initrd.img-$KR" -d initrd.img-$KR uInitrd-$KR
cp uInitrd-$KR   /media/boot
cp vmlinuz-$KR   /media/boot
cp /boot/dtbs/$KR/exynos4412-odroidu3.dtb /media/boot

Generating boot.scr

boot.scr is just uInitrd generated from boot.ini.

boot.ini:

...
setenv KR "4.16.0-odroid"
setenv bootcmd "fatload mmc 0:1 0x40008000 vmlinuz-${KR}; fatload mmc 0:1 0x42000000 uInitrd-${KR}; fatload mmc 0:1 0x44000000 exynos4412-odroidu3.dtb-${KR}; bootz 0x40008000 0x42000000 0x44000000"
...

Note the 3 files:

• vmlinuz-${KR} — kernel
• uInitrd-${KR} — generated from initrd.img-$KR
• exynos4412-odroidu3.dtb-${KR} — copied from /boot/dtbs/$KR

Then, generate boot.scr just like uInitrd above.

sudo mkimage -A arm -O linux -T script -C none -n "boot.ini-$KR" -d boot.ini-$KR boot.scr-$KR
sudo cp boot.ini-$KR  /media/boot/
sudo cp boot.ini-$KR  /media/boot/boot.ini
sudo cp boot.scr-$KR  /media/boot/
sudo cp boot.scr-$KR  /media/boot/boot.scr