Get the compiler , gcc-arm-none-eabi-4_7-2013q3-20130916-win32.exe or download it from my google drive ,install it , when it asks environment variable , just skip it .

https://drive.google.com/open?id=1-0Cy-zFqS9TJBSg7oknKmI__W69GrhNu

C:\Program Files (x86)\GNU Tools ARM Embedded\4.7 2013q3\bin\gccvar.bat run this , may be you can make a shortcut to desktop

move to the folder ,my project files are copied in D drive folder

d: 'enter' CD 'path' 'enter' Type 'make'

Linux/Mac users install suitable compiler & enter 'make'

FreeRTOS demo creates 2 Tasks , one controls LED & other prints text.

Connect to USB-UART to see task status

attached working kernel.img image & bootloader files for hands on

Works only on Raspberry Pi3 or BCM2837 ....