Add make extract

INSTALL.md

@@ -19,5 +19,15 @@ python tools/setup.py
 
 ## Build the ROM
 
-To build the ROM, simply run `make` in the root directory.
+This repository does not include any of the game's assets. You will need an original decrypted ROM for the version(s) you want
+to build.
+Put the original ROM in the root directory of this repository. Please verify that your dumped ROM matches one of the versions
+below:
 
+| Version | File name         | SHA1                                       | 
+| ------- | ----------------- | ------------------------------------------ |
+| EUR     | `baserom_eur.nds` | `02be55db55cf254bd064d2b3eb368b92a5b4156d` |
+
+Run `make extract` to extract from the base ROM. You only need to do this once.
+
+Once you have extracted the base ROM, simply run `make` to rebuild it.

Makefile

@@ -23,7 +23,8 @@ CXX_OBJS = $(CXX_FILES:%.cpp=$(TARGET_DIR)/%.o)
 OV_BINS := $(wildcard $(TARGET_DIR)/overlays/*.bin)
 OV_LZS = $(OV_BINS:%.bin=%.lz)
 
-NDS_FILE = ph_$(REGION_NAME).nds
+NDS_FILE := ph_$(REGION_NAME).nds
+BASE_ROM := baserom_$(REGION_NAME).nds
 
 MW_VER     := 2.0/sp1p5
 MW_ASM     := $(TOOLS_DIR)/mwccarm/$(MW_VER)/mwasmarm
@@ -49,6 +50,10 @@ tools:
 rom: arm9
 	$(TOOLS_DIR)/rom/buildrom -a $(BASE_DIR) -b $(TARGET_DIR) -r $(REGION_SUFFIX) -o $(NDS_FILE)
 
+.PHONY: extract
+extract:
+	$(TOOLS_DIR)/rom/extractrom -o $(BASE_DIR) -i $(BASE_ROM)
+
 .PHONY: arm9
 arm9: link
 	$(MAKE) compress

README.md

@@ -4,7 +4,7 @@
 assembly code by hand. **The repository only contains code.** To build the ROM, you must own an existing copy of the game to
 extract assets from.
 
-**Note:** The project can not build a ROM yet. Furthermore, it only targets the European version, and other versions will
+**Note:** The project can not build a ROM yet. Furthermore, it only targets the European version, and other versions might
 be supported later.
 
 ## How to install