pmpp

Available for:
 
4.13.10 cubox (Cubox-i, Hummingboards)
4.13.10 mvebu64 (Espressobin)
4.9.58  odroidxu4 (Odroid XU3/XU4)
4.13.10 rockchip (Tinkerboard, MiQi)
4.13.10 sunxi (All Allwinner 32bit boards)
4.13.10 sunxi64 (All Allwinner 64bit boards)
 
https://dl.armbian.com/_misc/realtime-kernel

Requirements:

- Armbian OS. Ubuntu or Debian bases.
- root credentials

Download: *dtb and *image packages at a minimum and install them with dpkg -i *.deb ... If you want to stay on this kernel, freeze upgrades in armbian-config -> system -> freeze kernel upgrades.

Remember that those kernels are bleeding edge, made from upstream sources and may have troubles. Consider them as is/experimental, without end-user support. If you want to build them - patches are present but .disabled and might not apply cleanly with more recent sources without adjustements.
 
What is RT?

I've just managed to build Devuan/Aarch64 for the Odroid C2 using the traditional debootstrap (on an Ubuntu host) way, so I might be able to patch the armbian/build scripts in order to generate a Devuan image.

Here are the steps to get a legacy H5 kernel running with Mali r5p0:
* Linux kernel from: https://github.com/OrangePiLibra/OrangePi_H5SDK
* Here is my legacy kernel generation script: https://pastebin.com/w1b4exzW
* Mali kernel module: DX910-SW-99002-r5p0-01rel0 from here: https://developer.arm.com/products/software/mali-drivers/utgard-kernel
* Mali kernel patch:  https://pastebin.com/VnJgZWZJ (name: DX910-SW-99002-r5p0-01rel0.patch)
* Blob: mali450r5p001rel0linux1fbdevarm64v8a
* Good benchmark/test utility: glmark2-es2-fb. The blob is a aarch64 one, so we must use a aarch64 linux environment to compile and run glmark2-es2-fb.
 
#script template:
#orangepi_h5sdk_dir link to repository: https://github.com/OrangePiLibra/OrangePi_H5SDK
yourkernelorangepih5sdkfullpath="<>"
f="DX910-SW-99002-r5p0-01rel0";rm -Rf mali_r5p0/;tar xf $f.tgz;(cd $f/;cat $f.patch|patch -p1);mv "$f/" mali_r5p0/; #mali450r5p001rel0linux1fbdevarm64v8a
mkdir -p mali_r5p0/driver/src/devicedrv/mali/include/linux/aw/sun50i/;
cp orangepi_h5sdk_dir/kernel/modules/gpu/mali450/kernel_mode/driver/src/devicedrv/mali/linux/mali_platform.c mali_r5p0/driver/src/devicedrv/mali/linux/mali_platform.c
cp -dpR orangepi_h5sdk_dir/kernel/modules/gpu/mali450/kernel_mode/driver/src/devicedrv/mali/include/linux/aw/platform.h mali_r5p0/driver/src/devicedrv/mali/include/linux/aw/
cp -dpR orangepi_h5sdk_dir/kernel/modules/gpu/mali450/kernel_mode/driver/src/devicedrv/mali/include/linux/aw/config.h mali_r5p0/driver/src/devicedrv/mali/include/linux/aw/
cp -dpR orangepi_h5sdk_dir/kernel/modules/gpu/mali450/kernel_mode/driver/src/devicedrv/mali/include/linux/aw/sun50i/sun50iw2p1.h mali_r5p0/driver/src/devicedrv/mali/include/linux/aw/sun50i/
sed -r -i "s/^(int mali_fb_start = )0(;)$/\10x7f040000\2/; s/^(int mali_fb_size = )0(;)$/\17372800\2/" mali_r5p0/driver/src/devicedrv/mali/common/mali_kernel_core.c; #from: fbset -i
#(cd mali_r5p0/driver/src/devicedrv/ump;(make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnueabihf- -j 8 KDIR=${yourkernelorangepih5sdkfullpath} V=1 BUILD=release))
(cd mali_r5p0/driver/src/devicedrv/mali;make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnueabihf- -j 8 KDIR=${yourkernelorangepih5sdkfullpath} V=1 USING_UMP=0 USING_DT=1 BUILD=release)