Compile own Kernel for FriendlyCore

[tt_citron]

Hi there,
for my NanoPi-M4 i am using latest friendlycore image on SDCARD (rk3399-sd-friendlycore-bionic-4.4-arm64-20180921). I develop application with Qt5 and it works so far. But now I get in trouble when using my FTDI232H based device.
Since the ftdi_sio driver is compiled directly into the kernel and not as a module, i have no chance to use my device with the FTD2xx library.
I know from other embedded boards that I have to compile my own kernel in this case. But to do so I need 2 things:
1) Kernel sources
2) Kernel configuration
On Github I only found kernel source tree for "FriendlyARM NanoPi (s3c2451)" and not for "NanoPi-M4 (RK3399)".

Any hint in which direction to go is very welcome.

Cheers
Thomas

[ericvh]

I followed the Lubuntu build your own kernel instructions but applied it to the FriendlyCore image and things seem fine.

git clone https://github.com/friendlyarm/kernel-rockchip --depth 1 -b nanopi4-linux-v4.4.y
cd kernel-rockchip
make ARCH=arm64 nanopi4_linux_defconfig
make ARCH=arm64 nanopi4-images

Update Lubuntu Kernel
To update the kernel you need to use the Linux_Upgrade_Tool_1.27.rar utility. Refer to the aforementioned sections on how to use this utility.