Implement make toolchain

.. this will download and build the 'cc65' and 'exomizer' prerequisites,
and then automatically pick them up on a subsequent 'make'.

.gitignore

@@ -1,3 +1,4 @@
 *.o
 *.prg
 *.bin
+bin

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "cc65"]
+	path = cc65
+	url = https://github.com/cc65/cc65
+[submodule "exomizer"]
+	path = exomizer
+	url = https://github.com/bitshifters/exomizer

Makefile

@@ -1,3 +1,5 @@
+export PATH:= $(abspath bin):$(PATH)
+
 .PHONY: all
 all: 80columns-compressed.prg 80c2-compressed.prg 80c3-compressed.prg 80c4-compressed.prg
 all: charset.prg charset2.prg charset3.prg charset4.prg
@@ -58,3 +60,30 @@ update-font-images: charset.bin charset2.bin charset3.bin charset4.bin mkfontimg
 .PHONY: clean
 clean:
 	rm -f *.prg *.bin *.o 80columns.d64
+
+.PHONY: toolchain
+toolchain: toolchain-cc65 toolchain-exomizer
+
+.PHONY: toolchain-cc65
+toolchain-cc65:
+	[ -d cc65/src ] || git submodule update --init cc65
+
+	$(MAKE) -C cc65 CC=cc bin
+
+	mkdir -p bin
+
+	cp cc65/bin/ca65 bin/
+	cp cc65/bin/ld65 bin/
+
+.PHONY: toolchain-exomizer
+toolchain-exomizer:
+	[ -d exomizer/exomizer2/src ] || git submodule update --init exomizer
+
+	$(MAKE) -C exomizer/exomizer2/src CFLAGS="-Wall -Wstrict-prototypes -pedantic -O3"
+
+	mkdir -p bin
+
+	cp exomizer/exomizer2/src/exomizer bin/
+
+	# have to do this, or git will report untracked files
+	(cd exomizer && git clean -dxf)

README.md

@@ -8,7 +8,10 @@ The code is based on 80COLUMNS.PRG by an unknown author. It has been reverse-eng
 
 ## Building
 
-Building requires a UNIX environment and [cc65](https://github.com/cc65/cc65) and [exomizer](https://github.com/bitshifters/exomizer). Running `make` will produce `80columns-compressed.prg`, which is about 2.2 KB in size and can be started using `LOAD`/`RUN`.
+Building requires a UNIX environment and [cc65](https://github.com/cc65/cc65) and [exomizer](https://github.com/bitshifters/exomizer).
+Running `make toolchain` will download and build cc65 and exomizer, assuming that you have a basic C development environment available.
+(If your system has packages of cc65 or exomizer, it is probably better to use those, e.g., with `brew install cc65 exomizer` on MacOS)
+Running `make` will produce `80columns-compressed.prg`, which is about 2.2 KB in size and can be started using `LOAD`/`RUN`.
 
 ## Features
 

cc65

@@ -0,0 +1 @@
+Subproject commit 6de78c536f78bc47129a7d4da4ad10f7e3a27b8f

exomizer

@@ -0,0 +1 @@
+Subproject commit 2426d97207c8dff23cd2a94cc768c8be87a7b5d0