Android kernel with UART and GPIO support question

[csd]

Hello,

I have already tried several guides how to compile my own kernel for Android, but I could not make it boot.

The device is OlinuXino A13 Wifi.

I followed the instructions described this guide and I could compile a zImage file: https://www.olimex.com/forum/index.php?topic=518.0
After that I replaced the zImage in the stock /dev/block/nandc block as described here: http://www.imajeenyus.com/computer/20130301_android_tablet/android/unpack_repack_recovery_image.html

Then: cat /data/nandc.img > /dev/block/nandc

I want to boot from NAND flash.

With this new nandc block the system tries to start (I monitor it from UART0 tty), but it hangs up when it starts the kernel. No error message, just hangs up.

What do I wrong?

I would be very happy if someone could provide me a working kernel with 2 UART port support (I don't need serial consol, but two working UARTs are needed) and the GPIO module (SUN4I_GPIO_UGLY = y).

I would also appreciate a working guide how to compile my own Android kernel.

Thanks in advance.