pokeemerald/INSTALL.md

Follow the OS-specific instructions below.

Linux

Install devkitARM.

Make sure that there is an environment variable called DEVKITARM with the path of the directory before the "bin" directory containing "arm-none-eabi-as", "arm-none-eabi-cpp", "arm-none-eabi-ld" and "arm-none-eabi-objcopy".

Then get the compiler from https://github.com/pret/agbcc and run the following commands.

./build.sh
./install.sh PATH_OF_POKEEMERALD_DIRECTORY

Finally, build the rom.

make

Windows

Install devkitARM.

Then get the compiled tools from https://github.com/pret/pokeruby-tools. Copy the tools/ folder over the tools/ folder in your pokeemerald directory.

You can then build pokeemerald using make in the MSYS environment provided with devkitARM.

Mac

Installing pokeemerald on a Mac requires macOS >= 10.12 (Sierra or higher).

Download a devkitPRO pacman

Run the following commands in Terminal:

xcode-select --install

sudo dkp-pacman -S devkitARM 

export DEVKITPRO=/opt/devkitpro
echo "export DEVKITPRO=$DEVKITPRO" >> ~/.bashrc
export DEVKITARM=$DEVKITPRO/devkitARM
echo "export DEVKITARM=$DEVKITARM" >> ~/.bashrc
echo "if [ -f ~/.bashrc ]; then . ~/.bashrc; fi" >> ~/.bash_profile

git clone https://github.com/pret/pokeemerald
git clone https://github.com/pret/agbcc

cd agbcc/
./build.sh
./install.sh ../pokeemerald 

cd ../pokeemerald
./build_tools.sh

And build the ROM with make.

If the step ./build.sh in the above list of commands fails with the error Makefile:1: /opt/devkitpro/devkitARM/base_tools: No such file or directory, then try installing the pacman package devkitarm-rules by executing the command

sudo dkp-pacman -S devkitarm-rules

Executing ./build.sh again should now succeed.

Faster builds

After the first build, subsequent builds are faster. You can further speed up the build:

Parallel build

This significantly speeds up the build on modern machines.

By default make only runs a single thread. You can tell make to run on multiple threads with make -j. See the manfile for usage (man make).

The optimal value for -j is the number of logical cores on your machine. You can run nproc to see the exact number.

$ nproc
8

If you have 8 cores, run: make -j8

-j on its own will spawn a new thread for each job. A clean build will have thousands of jobs, which will be slower than not using -j at all.

Disable the dependency scanning

If you've only changed .c or .s files, you can turn off the dependency scanning temporarily. Changes to any other files will be ignored, and the build will either fail or not reflect those changes.

make NODEP=1

Building with devkitARM's C compiler

This project supports the arm-none-eabi-gcc compiler which ships with devkitARM r52. To build this target, simply run:

make modern

Building with your own toolchain

To build Pokemon Emerald with a toolchain other than devkitARM, override the TOOLCHAIN environment variable with the path to your toolchain. Example:

make compare TOOLCHAIN=/usr/local/arm-none-eabi

The path you pass to the TOOLCHAIN variable must contain the subdirectory bin. If you compile the modern target with this toolchain, the subdirectories lib, include, and arm-none-eabi must also be present.

Building with debug info

To build the ELF file with enhanced debug info, use the DINFO variable:

make compare DINFO=1