Easily compile and simulate VHDL entities using GHDL and GTKWave. See instructions in the top comment.

makefile_vhdl

# By Etienne Collin
# https://gist.github.com/etiennecollin/198f7520c4c58d545368a196e08f83ed
# Dependencies (on macOS, install via Homebrew (https://brew.sh/)):
#   ghdl:
#     Source: https://github.com/ghdl/ghdl/
#   gtkwave:
#     Source: https://gtkwave.sourceforge.net/

#### INPUT REQUIRED ####
ENTITIES = entityName1 entityName2
VHDL_EXTENSION = vhd
VHDL_MAIN_PATH = .
VHDL_DEPENDENCIES_PATH = .
VHDL_ARGS = -fexplicit -fsynopsys --std=08
########################

OUT_DIR = out
VHDL_MAIN := $(VHDL_MAIN_PATH)/*.$(VHDL_EXTENSION)
VHDL_DEPENDENCIES := $(VHDL_DEPENDENCIES_PATH)/*.$(VHDL_EXTENSION)
CF := $(OUT_DIR)/*.cf
GHW := $(OUT_DIR)/*.ghw
ENTITY = $(OUT_DIR)/$${entity}.ghw

VHDL_MOD_TIME = $(OUT_DIR)/vhdl_last_modification_time.txt
CF_MOD_TIME = $(OUT_DIR)/cf_last_modification_time.txt

.PHONY: all simulate clear purge

all: $(GHW)

# Make this the dependency of $(CF) if the files are always compiled even when not modified
# $(VHDL_MOD_TIME): $(VHDL_DEPENDENCIES) $(VHDL_MAIN)
# 	@$(MAKE) checkstructure
# 	@[ -f "$(VHDL_MOD_TIME)" ] || touch $(VHDL_MOD_TIME)
# 	@find $(VHDL_DEPENDENCIES) $(VHDL_MAIN) -type f -exec stat -f "%m %N" {} \; | sort -nr | head -1 > $(VHDL_MOD_TIME)

$(CF): $(VHDL_DEPENDENCIES) $(VHDL_MAIN)
	@$(MAKE) checkstructure
	@echo "Analyzing $(VHDL_EXTENSION) files..."
	@ghdl -a $(VHDL_ARGS) --workdir=$(OUT_DIR) $(VHDL_DEPENDENCIES)
	@ghdl -a $(VHDL_ARGS) --workdir=$(OUT_DIR) $(VHDL_MAIN)
	@for entity in $(ENTITIES); do \
		echo "Compiling entity $${entity}..."; \
		ghdl -e $(VHDL_ARGS) --workdir=$(OUT_DIR) $${entity}; \
	done

# Make this the dependency of $(GHW) if the files are always compiled even when not modified
# $(CF_MOD_TIME): $(CF)
# 	@[ -f "$(CF_MOD_TIME)" ] || touch $(CF_MOD_TIME)
# 	@find $(CF) -type f -exec stat -f "%m %N" {} \; | sort -nr | head -1 > $(CF_MOD_TIME)

$(GHW): $(CF)
	@for entity in $(ENTITIES); do \
		echo "Generating $${entity}.ghw file..."; \
		ghdl -r $(VHDL_ARGS) --workdir=$(OUT_DIR) $${entity} --wave=$(ENTITY); \
	done


simulate: $(GHW)
	@for entity in $(ENTITIES); do \
		echo "Opening $${entity}.ghw in gtkwave..."; \
		open -a gtkwave $(ENTITY); \
	done

checkstructure:
	@[ -d $(OUT_DIR) ] || ( echo "Creating output directory..."; mkdir -p $(OUT_DIR) )

clear:
	@echo "Cleaning auto-generated files from output directory..."
	@rm -rf $(OUT_DIR)/*

purge:
	@echo "Purging auto-generated file structure..."
	@rm -rf $(OUT_DIR)

Makefile VHDL

This makefile supports:

• Compiling/simulating multiple VHDL entities at once.
• Dependency VHDL files that are placed in a directory different than your main directory.
• Incremental builds.

Installation

1. Download makefile_vhdl.
2. Rename makefile_vhdl to makefile.
3. Place the makefile in your project directory.

Dependencies

• GHDL
• GTKWave

On macOS, install the dependencies via Homebrew with the following command:

brew update && brew install ghdl gtkwave && brew cleanup

Setup

Set the required variables in the makefile (these variables are at the top of the makefile and marked by #### INPUT REQUIRED ####):

• ENTITIES: The name of the entities to simulate, separated by spaces.
• VHDL_EXTENSION: The extension you are using for your VHDL files (usually vhd or vhdl).
  • Do not put the . before the extension (such as .vhd or .vhdl); it is added automatically.
• VHDL_MAIN_PATH: The relative path to the directory containing your main VHDL files.
• VHDL_DEPENDENCIES_PATH: The relative path to the directory containing your VHDL dependencies (for example, components that are used in the main entity).
  • If you do not need a second directory, simply use the same path as the VHDL_MAIN_PATH.
• VHDL_ARGS: The arguments to pass to the GHDL compiler.

Run the makefile:

1. Open a new terminal in the project directory.
2. Type one of the available commands:
   • make: Compile the files and run the tests.
   • make simulate: Compile the files, run the tests and open in GTKWave.
   • make clear: Delete auto-generated compilation files.
   • make purge: Delete auto-generated compilation files and directory.