It works fine for axi_test, but I'm not sure if the latest GCC ARM version may cause issues when compiling Main_MiSTer. (ElectronAsh).
sudo apt-get update
sudo apt-get install libc6-armel-cross libc6-dev-armel-cross binutils-arm-linux-gnueabi libncurses5-dev build-essential bison flex libssl-dev bc
sudo apt-get install gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf
wget -c https://releases.linaro.org/components/toolchain/binaries/6.5-2018.12/arm-linux-gnueabihf/gcc-linaro-6.5.0-2018.12-x86_64_arm-linux-gnueabihf.tar.xz
tar xf gcc-linaro-6.5.0-2018.12-x86_64_arm-linux-gnueabihf.tar.xz -C /opt
export CC='/opt/gcc-linaro-6.5.0-2018.12-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc'
export PATH=$PATH:/opt/gcc-linaro-6.5.0-2018.12-x86_64_arm-linux-gnueabihf/bin
export PATH=$PATH:/opt/gcc-linaro-6.5.0-2018.12-x86_64_arm-linux-gnueabihf/lib
arm-linux-gnueabihf-gcc axi_test.c -o axi_test
sshpass -p "1" scp axi_test root@192.168.0.76:/media/fat/
sshpass -p '1' ssh root@192.168.0.76
(replace with the IP address from your main MiSTer OSD menu.)
cd /media/fat
./axi_test
The core MUST have AXI bridge support enabled, else running axi_test will likely crash the HPS, and it will self-restart after 10-20 seconds.