# Prerequisites

| Linux | macOS | Windows 10
| - | - | -
| none | [Xcode Command Line Tools Package][xcode] | [Windows Terminal][terminal] and [Windows Subsystem for Linux (WSL)][wsl]

[xcode]: https://developer.apple.com/library/archive/technotes/tn2339/_index.html
[terminal]: https://docs.microsoft.com/windows/terminal/get-started
[wsl]: https://docs.microsoft.com/windows/wsl/install-win10

Make sure that the `gcc`, `g++`, `make`, `git`, and `libpng` packages or their equivalents are installed. The package names and installation methods vary with each OS.

Install the devkitARM toolchain of devkitPro as per [the instructions on their wiki](https://devkitpro.org/wiki/devkitPro_pacman). On Windows, WSL is the development environment, thus any steps about the Windows installer do not apply.

The following tools are necessary depending on your needs:

* [porymap](https://github.com/huderlem/porymap) for viewing and editing maps
* [poryscript](https://github.com/huderlem/poryscript) for scripting ([VS Code extension](https://marketplace.visualstudio.com/items?itemName=karathan.poryscript))
* [Tilemap Studio](https://github.com/Rangi42/tilemap-studio) for viewing and editing tilemaps

**Windows 10 users:** WSL 2 is included starting in the 2004 release (build 19041) and will eventually become [the default for new installations](https://devblogs.microsoft.com/commandline/the-windows-subsystem-for-linux-build-2020-summary/#wsl2-default), therefore existing WSL 1 and [prerelease WSL](https://docs.microsoft.com/windows/wsl/install-legacy) users are recommended to update. Right-click the Start button and choose System to determine the Windows version.

**Windows 7 and 8.1 users:** pret is no longer focusing on support in pokeemerald for [old versions of Windows](https://support.microsoft.com/help/13853) so consider upgrading to a current release of Windows 10 or try a third-party guide like [this one](https://www.pokecommunity.com/showthread.php?t=425246) instead.


# Installation

To set up the repository:

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

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

	cd ../pokeemerald

To build **pokeemerald.gba** for the first time and confirm it matches the official ROM image:

	make compare

If an OK is returned, then the installation went smoothly.


# Start

To build **pokeemerald.gba** with your changes:

	make

**macOS users:** If the base tools are not found in new Terminal sessions after the first successful build, run `echo "if [ -f ~/.bashrc ]; then . ~/.bashrc; fi" >> ~/.bash_profile` once to prevent the issue from occurring again. Verify that the `devkitarm-rules` package is installed as well; if not, install it by running `sudo dkp-pacman -S devkitarm-rules`.


# Building guidance


## Parallel builds

See [the GNU docs](https://www.gnu.org/software/make/manual/html_node/Parallel.html) and [this Stack Exchange thread](https://unix.stackexchange.com/questions/208568) for more information.

To speed up building, run:

	make -j$(nproc)

`nproc` is not available on macOS. The alternative is `sysctl -n hw.ncpu` ([relevant Stack Overflow thread](https://stackoverflow.com/questions/1715580)).


## Debug info

To build **pokeemerald.elf** with enhanced debug info:

	make DINFO=1


## devkitARM's C compiler

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

	make modern


## 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.