Organize folders and build system to prepare for small revamp

Goals include:
* To recover emulator code into a working state (using SDL2 as I cannot
  use the Windows library)
* To allow memory management in emulator to not mirror the intricacies
  of the calculator version (eg. aSystemStack, aVRAMBuffer, etc)
* To recover actual printf-style error messages on the calculator
* To use the standard library and avoid random reimplementations of
  functions
* And other code cleanups that are only possible with CGDoom-specific
  header files, instead of the mix in platform.h and os.h

.gitignore

@@ -1,5 +1,2 @@
-*.o
-CG_Doom.bin
-CG_Doom.elf
-CG_Doom.map
-doom.wad
+build-cg/
+build-sdl2/

CGDOOM-minisdk/CGDOOM/Makefile

@@ -1,40 +0,0 @@
-CC=sh-elf-gcc
-CPP=sh-elf-g++
-OBJCOPY=sh-elf-objcopy
-MKG3A=mkg3a
-RM=rm
-CFLAGS=-m4a-nofpu -mb -fgcse-sm -fgcse-las -fgcse-after-reload -Isrc -O3 -fmerge-all-constants -mhitachi -fuse-linker-plugin -fstrict-volatile-bitfields -Wall -Wextra -Wno-sign-compare -Wno-unused-but-set-variable -Wno-unused-but-set-parameter -I../../../../include -lgcc -L../../../../lib -I./ -I../../cgdoom -D_FXCG_MINICOMPAT
-LDFLAGS=$(CFLAGS) -nostartfiles -T../../../../toolchain/prizm.x -Wl,-static -lfxcg -lgcc -Wl,-Map=$(PROJ_NAME).map
-CSOURCES=$(wildcard ../../cgdoom/*.c)
-ASMSOURCES=$(wildcard ../../cgdoom/*.s)
-OBJECTS=$(CSOURCES:.c=.o) $(ASMSOURCES:.s=.o)
-PROJ_NAME=CG_Doom
-BIN=$(PROJ_NAME).bin
-ELF=$(PROJ_NAME).elf
-ADDIN=$(PROJ_NAME).g3a
- 
-all: $(ADDIN)
- 
- 
-$(ADDIN): $(BIN)
-	$(MKG3A) -n : -i uns:CGDOOM_UNSELECTED.png -i sel:CGDOOM_SELECTED.png $< $@
- 
-.s.o:
-	$(CC) -c $(CFLAGS) $< -o $@
- 
-.c.o:
-	$(CC) -c $(CFLAGS) $< -o $@
-	
-.cpp.o:
-	$(CC) -c $(CFLAGS) $< -o $@
-	
-.cc.o:
-	$(CC) -c $(CFLAGS) $< -o $@
-
-$(ELF): $(OBJECTS)
-	$(CC) $(OBJECTS) $(LDFLAGS) -o $@
-$(BIN): $(ELF)
-	$(OBJCOPY) -O binary $(PROJ_NAME).elf $(BIN)
-
-clean:
-	rm -f $(OBJECTS) $(PROJ_NAME).bin $(PROJ_NAME).elf $(ADDIN)

Makefile

@@ -0,0 +1,101 @@
+# Makefile for the fx-CG 50 / Graph 90+E version of CGDoom.
+# Two target platforms: fx-CG and native (SDL2).
+
+### Project structure.
+
+NAME := CGDoom
+SRC := $(wildcard cgdoom/*.c cgdoom/*.s)
+
+CFLAGS := -I cgdoom
+# Extra optimization passes just in case
+CFLAGS += -O3 -fgcse-sm -fgcse-las -fgcse-after-reload -fmerge-all-constants
+# We remove some warnings that come up a lot in Doom
+CFLAGS += -Wall -Wextra -Wno-sign-compare -Wno-unused-but-set-variable -Wno-unused-but-set-parameter
+
+LDFLAGS :=
+
+### fx-CG 50 build.
+
+CG_CC      := sh-elf-gcc
+CG_OBJCOPY := sh-elf-objcopy
+
+# The libfxcg install folder (adjust to your needs)
+LIBFXCG_ROOT := ../..
+
+# Platform selection
+CG_CFLAGS := $(CFLAGS) -I src-cg -m4a-nofpu -mb -mhitachi
+# Enforce strict access size in volatile bitfields, needed for PRAM mainly
+CG_CFLAGS += -fstrict-volatile-bitfields
+# We use libfxcg and libc within the libfxcg repository
+CG_CFLAGS += -I $(LIBFXCG_ROOT)/include -D_FXCG_MINICOMPAT
+
+# Libraries specific to libfxcg and the cross-compiler
+CG_LDFLAGS := $(LDFLAGS) -L $(LIBFXCG_ROOT)/lib -lfxcg -lgcc
+# The build is mostly free-standing, with the libfxcg linker script
+CG_LDFLAGS += -nostartfiles -T $(LIBFXCG_ROOT)/toolchain/prizm.x
+# Generate a map of every function and global variable for debugging
+CG_LDFLAGS += -Wl,-Map=build-cg/$(NAME).map
+
+CG_SRC := $(SRC) $(wildcard src-fxcg/*.c src-fxcg/*.s)
+CG_OBJ := $(CG_SRC:cgdoom/%=build-cg/%.o)
+
+### Native SDL2 build.
+
+CC ?= gcc
+
+SDL2_CFLAGS := $(CFLAGS) -I src-sdl2 -DCG_EMULATOR $(pkg-config sdl2 --cflags)
+SDL2_LDFLAGS := $(LDFLAGS) $(pkg-config sdl2 --libs)
+
+SDL2_SRC := $(SRC) $(wildcard src-sdl2/*.c)
+SDL2_OBJ := $(SDL2_SRC:cgdoom/%=build-sdl2/%.o)
+
+### Build rules.
+
+all: all-cg50
+
+#~
+
+all-cg50: $(NAME).g3a
+
+$(NAME).g3a: build-cg/$(NAME).bin
+	mkg3a -n : -i uns:CGDOOM_UNSELECTED.png -i sel:CGDOOM_SELECTED.png $< $@
+
+build-cg/%.s.o: cgdoom/%.s | build-cg/
+	$(CG_CC) $(CG_CFLAGS) -c $< -o $@
+
+build-cg/%.c.o: cgdoom/%.c | build-cg/
+	$(CG_CC) $(CG_CFLAGS) -c $< -o $@
+
+build-cg/%.c.o: src-cg/%.c | build-cg/
+	$(CG_CC) $(CG_CFLAGS) -c $< -o $@
+
+build-cg/$(NAME).elf: $(CG_OBJ)
+	$(CG_CC) $(CG_CFLAGS) $(CG_LDFLAGS) $^ -o $@
+
+build-cg/$(NAME).bin: build-cg/$(NAME).elf
+	$(CG_OBJCOPY) -O binary $< $@
+
+#~
+
+all-sdl2: $(NAME)
+
+$(NAME): $(SDL2_OBJ)
+	$(CC) $(SDL2_CFLAGS) $(SDL2_LDFLAGS) $^ -o $@
+
+build-sdl2/%.c.o: cgdoom/%.c | build-sdl2/
+	$(CC) $(SDL2_CFLAGS) -c $< -o $@
+
+build-sdl2/%.c.o: src-sdl2/%.c | build-sdl2/
+	$(CC) $(SDL2_CFLAGS) -c $< -o $@
+
+#~
+
+clean:
+	rm -rf build-cg/ build-sdl2/
+
+%/:
+	@ mkdir -p $@
+
+.PRECIOUS: %/ build-cg/%.d build-sdl2/%.d
+
+include $(wildcard build-cg/*.d build-sdl2/*.d)

src-cg/platform.h

@@ -97,11 +97,6 @@ enum {
 #define WIDTH 384
 #define HEIGHT 216
 
-#define KEY_PRGM_OPTN 68
-#define KEY_PRGM_MENU 48
-#define KEY_PRGM_POWER 57
-#define KEY_PRGM_EXE 31
-
 #define EmulHack_Sleep(x)
 #define ASSERT(x)
 #define InitFlashSimu(filename)