Answer

How to generate GCC Makefile for project

The GCC Makefile for the projects can be generated using Simplicity Studio project generator option “GCC Makefile”. Once generated the project can be built outside of the Simplicity Studio using make tools

Steps to generate

• Open *.slcp file in Simplicity Studio 
• Change to Overview tab 
• Select Edit in Project Generators

• Check GCC MAKEFILE option 
• Push Save button 

Once the Makefiles were generated, they can be updated outside of the Simplicity Studio as needed:

• “GCC Makefile” option generates two files (*.Makefile and *.mak)
• The path to the location of the project and makefiles are at Resource Location property. To open please right click on the project -> Properties

Summary

The project can be built with “make -f *.Makefile …” command from  “Command Prompt” or using Cigwin on windows. Other platforms: iOS, Linux support “make” command natively.  
The “make” utility generates: *.hex, and *.bin files which are firmware executables. They can be loaded to the internal flash using SWD interface, bootloader UART interface or other methods.
Please note that bootloader UART interface accepting firmware image in [GBL] format and generated by Make utility files should be converted before using this method.