Instructions

These instructions explain how to set up the tools required to build pokeemerald, which assembles the source files into a ROM.

These instructions come with notes which can be expanded by clicking the "Note..." text. In general, you should not need to open these unless if you get an error or if you need additional clarification.

If you run into trouble, ask for help on Discord or IRC (see README.md).

Windows

Windows has instructions for building with three possible terminals, providing 3 different options in case the user stumbles upon unexpected errors.

Windows 10/11 (WSL1) (Fastest, highly recommended, Windows 10 and 11 only)
Windows (msys2) (Second fastest)
Windows (Cygwin) (Slowest)

Unscientific benchmarks suggest msys2 is 2x slower than WSL1, and Cygwin is 5-6x slower than WSL1.

Note for advanced users: WSL2...

WSL2 is an option and is even faster than WSL1 if files are stored on the WSL2 file system, but some tools may have trouble interacting with the WSL2 file system over the network drive. For example, tools which use Qt versions before 5.15.2 such as porymap may have problems with parsing the \wsl$ network drive path.

All of the Windows instructions assume that the default drive is C:\. If this differs to your actual drive letter, then replace C with the correct drive letter when reading the instructions.

A note of caution: As Windows 7 and Windows 8 are officially unsupported by Microsoft, some maintainers are unwilling to maintain the Windows 7/8 instructions. Thus, these instructions may break in the future with fixes taking longer than fixes to the Windows 10/11 instructions.

Windows 10/11 (WSL1)

WSL1 is the preferred terminal to build pokeemerald. The following instructions will explain how to install WSL1 (referred to interchangeably as WSL).

If WSL (Debian or Ubuntu) is not installed, then go to Installing WSL1.
Otherwise, if WSL is installed, but it hasn't previously been set up for another decompilation project, then go to Setting up WSL1.
Otherwise, open WSL and go to Choosing where to store pokeemerald (WSL1).

Installing WSL1

Open Windows Powershell as Administrator, and run the following commands (Right Click or Shift+Insert is paste in the Powershell).
```
wsl --install -d Ubuntu --enable-wsl1
```
Once the process finishes, restart your machine.
Open Windows Powershell as Administrator again (after restarting), and run the following command to configure Ubuntu to use WSL1.
```
wsl --set-version Ubuntu 1
```
Note...

WSL may open automatically after restarting, but you can ignore it for now.

Setting up WSL1

Some tips before proceeding:

In WSL, Copy and Paste is either done via
- right-click (selection + right click to Copy, right click with no selection to Paste)
- Ctrl+Shift+C/Ctrl+Shift+V (enabled by right-clicking the title bar, going to Properties, then checking the checkbox next to "Use Ctrl+Shift+C/V as Copy/Paste").
Some of the commands that you'll run will ask for your WSL password and/or confirmation to perform the stated action. This is to be expected, just enter your WSL password and/or the yes action when necessary.

Open Ubuntu (e.g. using Search).
WSL/Ubuntu will set up its own installation when it runs for the first time. Once WSL/Ubuntu finishes installing, it will ask for a username and password (to be input in).

Note...

When typing in the password, there will be no visible response, but the terminal will still read in input.
Update WSL/Ubuntu before continuing. Do this by running the following command. These commands will likely take a long time to finish:
```
sudo apt update && sudo apt upgrade
```

Note: If the repository you plan to build has an older revision of the INSTALL.md, then follow the legacy WSL1 instructions from here.

Certain packages are required to build pokeemerald. Install these packages by running the following command:
```
sudo apt install build-essential binutils-arm-none-eabi git libpng-dev
```
Note...

If the above command does not work, try the above command but replacing apt with apt-get.

Choosing where to store pokeemerald (WSL1)

WSL has its own file system that's not natively accessible from Windows, but Windows files are accessible from WSL. So you're going to want to store pokeemerald within Windows.

For example, say you want to store pokeemerald (and agbcc) in C:\Users\<user>\Desktop\decomps. First, ensure that the folder already exists. Then, enter this command to change directory to said folder, where <user> is your Windows username:

cd /mnt/c/Users/<user>/Desktop/decomps

Notes...

Note 1: The Windows C:\ drive is called /mnt/c/ in WSL. Note 2: If the path has spaces, then the path must be wrapped with quotations, e.g. cd "/mnt/c/users/<user>/Desktop/decomp folder". Note 3: Windows path names are case-insensitive so adhering to capitalization isn't needed

If this works, then proceed to Installation.

Otherwise, ask for help on Discord or IRC (see README.md), or continue reading below for Windows instructions using msys2.

Windows (msys2)

If devkitARM is not installed, then go to Installing devkitARM.
If devkitARM is installed, but msys2 hasn't previously been set up for another decompilation project, then go to Setting up msys2.
Otherwise, open msys2 and go to Choosing where to store pokeemerald (msys2).

Installing devkitARM

Download the devkitPro installer here.
Run the devkitPro installer. In the "Choose Components" screen, uncheck everything except GBA Development unless if you plan to install other devkitPro components for other purposes. Keep the install location as C:\devkitPro and leave the Start Menu option unchanged.

Setting up msys2

Note that in msys2, Copy is Ctrl+Insert and Paste is Shift+Insert.

Open msys2 at C:\devkitPro\msys2\msys2_shell.bat.
Certain packages are required to build pokeemerald. Install these by running the following two commands:
```
pacman -Sy msys2-keyring
pacman -S make gcc zlib-devel git
```
Note...

The commands will ask for confirmation, just enter the yes action when prompted.
Download libpng.
Change directory to where libpng was downloaded. By default, msys2 will start in the current user's profile folder, located at C:\Users\⁠<user>, where <user> is your Windows username. In most cases, libpng should be saved within a subfolder of the profile folder. For example, if libpng was saved to C:\Users\<user>\Downloads (the Downloads location for most users), enter this command:
```
cd Downloads
```
Notes...

Note 1: While not shown, msys uses forward slashes / instead of backwards slashes \ as the directory separator. Note 2: If the path has spaces, then the path must be wrapped with quotations, e.g. cd "Downloads/My Downloads". Note 3: Windows path names are case-insensitive so adhering to capitalization isn’t needed. Note 4: If libpng was saved elsewhere, you will need to specify the full path to where libpng was downloaded, e.g. cd c:/devkitpro/msys2 if it was saved there.

Run the following commands to uncompress and install libpng.

tar xf libpng-1.6.37.tar.xz
cd libpng-1.6.37
./configure --prefix=/usr
make check
make install

Then finally, run the following command to change back to the user profile folder.
```
cd
```

Choosing where to store pokeemerald (msys2)

At this point, you can choose a folder to store pokeemerald into. If you're okay with storing pokeemerald in the user profile folder, then proceed to Installation. Otherwise, you'll need to account for where pokeemerald is stored when changing directory to the pokeemerald folder.

For example, if you want to store pokeemerald (and agbcc) in C:\Users\<user>\Desktop\decomps (where <user> is your Windows username), enter this command:

cd Desktop/decomps

If this works, then proceed to Installation.

Otherwise, ask for help on Discord or IRC (see README.md), or continue reading below for Windows instructions using Cygwin.

Windows (Cygwin)

If devkitARM is not installed, then follow the instructions used to install devkitARM for the msys2 setup before continuing. Remember to not continue following the msys2 instructions by mistake!
- If Cygwin is not installed, or does not have all of the required packages installed, then go to Installing Cygwin.
- If Cygwin is installed, but is not configured to work with devkitARM, then go to Configuring devkitARM for Cygwin.
- Otherwise, open Cygwin and go to Choosing where to store pokeemerald (Cygwin)

Installing Cygwin

Download Cygwin: setup-x86_64.exe for 64-bit Windows, setup-x86.exe for 32-bit.
Run the Cygwin setup. Within the Cygwin setup, leave the default settings until the "Choose A Download Site" screen.
At "Choose a Download Site", select any mirror within the Available Download Sites.
At "Select Packages", set the view to "Full" (top left) and search for the following packages:
- make
- git
- gcc-core
- gcc-g++
- libpng-devel
To quickly find these, use the search bar and type the name of each package. Ensure that the selected package name is the exact same as the one you're trying to download, e.g. cmake is NOT the same as make.
For each package, double click on the text that says "Skip" next to each package to select the most recent version to install. If the text says anything other than "Skip", (e.g. Keep or a version number), then the package is or will be installed and you don't need to do anything.
Once all required packages have been selected, finish the installation.

Configuring devkitARM for Cygwin

Note that in Cygwin, Copy is Ctrl+Insert and Paste is Shift+Insert.

Open Cygwin.

Run the following commands to configure devkitPro to work with Cygwin.

export DEVKITPRO=/cygdrive/c/devkitpro
echo export DEVKITPRO=$DEVKITPRO >> ~/.bashrc
export DEVKITARM=$DEVKITPRO/devkitARM
echo export DEVKITARM=$DEVKITARM >> ~/.bashrc

Note...

Replace the drive letter c with the actual drive letter if it is not c.

Choosing where to store pokeemerald (Cygwin)

Cygwin has its own file system that's within Windows, at C:\cygwin64\home\<user>. If you don't want to store pokeemerald there, you'll need to account for where pokeemerald is stored when changing directory to the pokeemerald folder.

For example, if you want to store pokeemerald (and agbcc) in C:\Users\<user>\Desktop\decomps, enter this command, where <user> is your Windows username:

cd c:/Users/<user>/Desktop/decomps

Note that the directory must exist in Windows. If you want to store pokeemerald in a dedicated folder that doesn't exist (e.g. the example provided above), then create the folder (e.g. using Windows Explorer) before executing the cd command.

Notes...

Note 1: If the path has spaces, then the path must be wrapped with quotations, e.g. cd "c:/users/<user>/Desktop/decomp folder". Note 2: Windows path names are case-insensitive so adhering to capitalization isn't needed

If this works, then proceed to Installation. Otherwise, ask for help on Discord or IRC (see README.md).

macOS

If the Xcode Command Line Tools are not installed, download the tools here, open your Terminal, and run the following command:
```
xcode-select --install
```
- If libpng is not installed, then go to Installing libpng (macOS).
- If devkitARM is not installed, then go to Installing devkitARM (macOS).
- Otherwise, open the Terminal and go to Choosing where to store pokeemerald (macOS)

Installing libpng (macOS)

Note for advanced users...

This guide installs libpng via Homebrew as it is the easiest method, however advanced users can install libpng through other means if they so desire.

Open the Terminal.
If Homebrew is not installed, then install Homebrew by following the instructions on the website.
Run the following command to install libpng.
```
brew install libpng
```
libpng is now installed.

Continue to Installing devkitARM (macOS) if devkitARM is not installed, otherwise, go to Choosing where to store pokeemerald (macOS).

Installing devkitARM (macOS)

Download the devkitpro-pacman-installer.pkg package from here.
Open the package to install devkitPro pacman.
In the Terminal, run the following commands to install devkitARM:
```
sudo dkp-pacman -Sy
sudo dkp-pacman -S gba-dev
sudo dkp-pacman -S devkitarm-rules
```
The command with gba-dev will ask for the selection of packages to install. Just press Enter to install all of them, followed by entering Y to proceed with the installation.

After the tools are installed, devkitARM must now be made accessible from anywhere by the system. To do so, run the following commands:

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

Choosing where to store pokeemerald (macOS)

At this point, you can choose a folder to store pokeemerald into. If you're okay with storing pokeemerald in the user folder, then proceed to Installation. Otherwise, you'll need to account for where pokeemerald is stored when changing directory to the pokeemerald folder.

For example, if you want to store pokeemerald (and agbcc) in ~/Desktop/decomps, enter this command to change directory to the desired folder:

cd Desktop/decomps

Note that the directory must exist in the folder system. If you want to store pokeemerald in a dedicated folder that doesn't exist (e.g. the example provided above), then create the folder (e.g. using Finder) before executing the cd command.

Note...

Note: If the path has spaces, then the path must be wrapped with quotations, e.g. cd "Desktop/decomp folder"

If this works, then proceed to Installation. Otherwise, ask for help on Discord or IRC (see README.md).

Linux

Open Terminal and enter the following commands, depending on which distro you're using.

Debian/Ubuntu-based distributions

Run the following command to install the necessary packages:

sudo apt install build-essential binutils-arm-none-eabi git libpng-dev

Then proceed to Choosing where to store pokeemerald (Linux).

Note for legacy repos...

If the repository you plan to build has an older revision of the INSTALL.md, then you will have to install devkitARM. Install all the above packages except binutils-arm-none-eabi, and follow the instructions to install devkitARM on Debian/Ubuntu-based distributions.

Arch Linux

Run this command as root to install the necessary packages:

pacman -S base-devel arm-none-eabi-binutils git libpng

Then proceed to Choosing where to store pokeemerald (Linux).

Note for legacy repos...

If the repository you plan to build has an older revision of the INSTALL.md, then you will have to install devkitARM. Install all the above packages except binutils-arm-none-eabi, and follow the instructions to install devkitARM on Arch Linux.

NixOS

Run the following command to start an interactive shell with the necessary packages:

nix-shell -p pkgsCross.arm-embedded.stdenv.cc git pkg-config libpng

Then proceed to Choosing where to store pokeemerald (Linux).

Other distributions

(Specific instructions for other distributions would be greatly appreciated!)

Try to find the required software in its repositories:
- gcc
- g++
- make
- git
- libpng-dev
Follow the instructions here to install devkitPro pacman. As a reminder, the goal is to configure an existing pacman installation to recognize devkitPro's repositories.
Once devkitPro pacman is configured, run the following commands:
```
sudo pacman -Sy
sudo pacman -S gba-dev
```
The last command will ask for the selection of packages to install. Just press Enter to install all of them, followed by entering Y to proceed with the installation.

Choosing where to store pokeemerald (Linux)

At this point, you can choose a folder to store pokeemerald (and agbcc) into. If so, you'll have to account for the modified folder path when changing directory to the pokeemerald folder.

If this works, then proceed to Installation. Otherwise, ask for help on Discord or IRC (see README.md).

Installation

Note for Windows users...

Consider adding an exception for the pokeemerald and/or decomps folder in Windows Security using these instructions. This prevents Microsoft Defender from scanning them which might improve performance while building.

If pokeemerald is not already downloaded (some users may prefer to download pokeemerald via a git client like GitHub Desktop), run:
```
git clone https://github.com/pret/pokeemerald
```
Note for WSL1...
If you get an error stating fatal: could not set 'core.filemode' to 'false', then run the following commands:
```
cd
sudo umount /mnt/c
sudo mount -t drvfs C: /mnt/c -o metadata,noatime
cd <folder where pokeemerald is to be stored>
```
Where <folder where pokeemerald is to be stored> is the path of the folder where you chose to store pokeemerald. Then run the git clone command again.
Install agbcc into pokeemerald. The commands to run depend on certain conditions. You should only follow one of the listed instructions:

If agbcc has not been built before in the folder where you chose to store pokeemerald, run the following commands to build and install it into pokeemerald:
```
git clone https://github.com/pret/agbcc
cd agbcc
./build.sh
./install.sh ../pokeemerald
```
Otherwise, if agbcc has been built before (e.g. if the git clone above fails), but was last built on a different terminal than the one currently used (only relevant to Windows, e.g. switching from msys2 to WSL1), then run the following commands to build and install it into pokeemerald:
```
cd agbcc
git clean -fX
./build.sh
./install.sh ../pokeemerald
```

Otherwise, if agbcc has been built before on the same terminal, run the following commands to install agbcc into pokeemerald:

cd agbcc
./install.sh ../pokeemerald

Note...

  > If building agbcc or pokeemerald results in an error, try deleting the agbcc folder and re-installing agbcc as if it has not been built before.

Once agbcc is installed, change directory back to the base directory where pokeemerald and agbcc are stored:
```
cd ..
```

Now you're ready to build pokeemerald

Build pokeemerald

If you aren't in the pokeemerald directory already, then change directory to the pokeemerald folder:

cd pokeemerald

To build pokeemerald.gba (Note: to speed up builds, see Parallel builds):

make

If it has built successfully you will have the output file pokeemerald.gba in your project folder.

Note for Windows...

> If you switched terminals since the last build (e.g. from msys2 to WSL1), you must run `make clean-tools` once before any subsequent `make` commands.

Building guidance

Parallel builds

See the GNU docs and this Stack Exchange thread for more information.

To speed up building, first get the value of nproc by running the following command:

nproc

Builds can then be sped up by running the following command:

make -j<output of nproc>

Replace <output of nproc> with the number that the nproc command returned.

nproc is not available on macOS. The alternative is sysctl -n hw.ncpu (relevant Stack Overflow thread).

Compare ROM to the original

For contributing, or if you'd simply like to verify that your ROM is identical to the original game, run:

make compare

If it matches, you will see the following at the end of the output:

pokeemerald.gba: OK

If there are any changes from the original game, you will instead see:

pokeemerald.gba: FAILED
shasum: WARNING: 1 computed checksum did NOT match

devkitARM's C compiler

This project supports the arm-none-eabi-gcc compiler included with devkitARM. If devkitARM (a.k.a. gba-dev) has already been installed as part of the platform-specific instructions, simply run:

make modern

Otherwise, follow the instructions below to install devkitARM.

Installing devkitARM on WSL1

gdebi-core must be installed beforehand in order to install devkitPro pacman (which facilitates the installation of devkitARM). Install this with the following command:
```
sudo apt install gdebi-core
```
Note...

If the above command does not work, try the above command but replacing apt with apt-get.
Once gdebi-core is done installing, download the devkitPro pacman package here. The file to download is devkitpro-pacman.amd64.deb.
Change directory to where the package was downloaded. For example, if the package file was saved to C:\Users\<user>\Downloads (the Downloads location for most users), enter this command, where *<user> is your Windows username:
```
cd /mnt/c/Users/<user>/Downloads
```
Once the directory has been changed to the folder containing the devkitPro pacman package, run the following commands to install devkitARM.
```
sudo gdebi devkitpro-pacman.amd64.deb
sudo dkp-pacman -Sy
sudo dkp-pacman -S gba-dev
```
The last command will ask for the selection of packages to install. Just press Enter to install all of them, followed by entering Y to proceed with the installation.

Note...

Note: devkitpro-pacman.amd64.deb is the expected filename of the devkitPro package downloaded (for the first command). If the downloaded package filename differs, then use that filename instead.
Run the following command to set devkitPro related environment variables (alternatively, close and re-open WSL):
```
source /etc/profile.d/devkit-env.sh
```

devkitARM is now installed.

Installing devkitARM on Debian/Ubuntu-based distributions

If gdebi-core is not installed, run the following command:
```
sudo apt install gdebi-core
```
Download the devkitPro pacman package here. The file to download is devkitpro-pacman.amd64.deb.
Change directory to where the package was downloaded. Then, run the following commands to install devkitARM:
```
sudo gdebi devkitpro-pacman.amd64.deb
sudo dkp-pacman -Sy
sudo dkp-pacman -S gba-dev
```
The last command will ask for the selection of packages to install. Just press Enter to install all of them, followed by entering Y to proceed with the installation.

Note: devkitpro-pacman.amd64.deb is the expected filename of the devkitPro package downloaded (for the first command). If the downloaded package filename differs, then use that filename instead.
Run the following command to set devkitPro related environment variables (alternatively, close and re-open the Terminal):
```
source /etc/profile.d/devkit-env.sh
```

devkitARM is now installed.

Installing devkitARM on Arch Linux

Follow devkitPro's instructions to configure pacman to download devkitPro packages.
Install gba-dev: run the following command as root.
```
pacman -S gba-dev
```
This will ask for the selection of packages to install. Just press Enter to install all of them, followed by entering Y to proceed with the installation.
Run the following command to set devkitPro related environment variables (alternatively, close and re-open the Terminal):
```
source /etc/profile.d/devkit-env.sh
```

devkitARM is now installed.

Other toolchains

To build using a toolchain other than devkitARM, override the TOOLCHAIN environment variable with the path to your toolchain, which must contain the subdirectory bin.

make TOOLCHAIN="/path/to/toolchain/here"

The following is an example:

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

To compile the modern target with this toolchain, the subdirectories lib, include, and arm-none-eabi must also be present.

Building with debug info under a modern toolchain

To build pokeemerald.elf with debug symbols under a modern toolchain:

make modern DINFO=1

Note that this is not necessary for a non-modern build since those are built with debug symbols by default.

Useful additional tools

porymap for viewing and editing maps
poryscript for scripting (VS Code extension)
Tilemap Studio for viewing and editing tilemaps

Files

INSTALL.md

Latest commit

History

INSTALL.md

File metadata and controls

Instructions

Windows

Windows 10/11 (WSL1)

Installing WSL1

Setting up WSL1

Choosing where to store pokeemerald (WSL1)

Windows (msys2)

Installing devkitARM

Setting up msys2

Choosing where to store pokeemerald (msys2)

Windows (Cygwin)

Installing Cygwin

Configuring devkitARM for Cygwin

Choosing where to store pokeemerald (Cygwin)

macOS

Installing libpng (macOS)

Installing devkitARM (macOS)

Choosing where to store pokeemerald (macOS)

Linux

Debian/Ubuntu-based distributions

Arch Linux

NixOS

Other distributions

Choosing where to store pokeemerald (Linux)

Installation

Build pokeemerald

Building guidance

Parallel builds

Compare ROM to the original

devkitARM's C compiler

Installing devkitARM on WSL1

Installing devkitARM on Debian/Ubuntu-based distributions

Installing devkitARM on Arch Linux

Other toolchains

Building with debug info under a modern toolchain

Useful additional tools