build_system.md

The build system

The build system uses make to invoke the various tools required to build this project. The hardware simulation makes use of Icarus Verilog. The top-level design for the Colorlight board is synthesized and implemented by Yosys and nextpnr-ecp5. All of these tools are contained within the Yosys oss-cad-suite. The assembler for the toymcu is compiled using GCC.

Using the build system

The makefile found in the root of this repository contains several targets:

• toy_program

  • compiles the toyasm assembler and assembles the source files specified in the makefile into a memory file which can then be sent to the toymcu by the loader tool

• toy_bootrom

  • compiles the toyasm assembler and assembles the boot ROM.

• hw_sim

  • builds the toy_bootrom target, then runs the hardware simulation, using the included testbench and outputs the simulation result as a VCD file (tb_tov.vcd) in the root of the repo. The simulation result can be visualised using GTKWave (included in the oss-cad-suite)

• hw

  • builds the toy_bootrom target, then synthesizes and implements the toymcu top-level design for the Colorlight 5A-75B V8.2 board. The I/O constraints are specified in this file. The build result of this target is a bitstream file (colorlight_toy_top.bit).

• hw_prog

  • builds the hw target and uses ecpdap to program the bitstream into the FPGA.

• toy_load

  • builds the toy_program target, compiles the loader tool and then sends the assembled program over the serial port specified in the makefile.

• clean

  • removes all resulting build files