koreader/doc/Building_targets.md

Building targets

KOReader is available for multiple platforms. Here are instructions to build installable packages for all these platforms.

These instructions are intended for a Linux OS. MacOS and Windows users are suggested to develop in a Linux VM.

Prerequisites

This instructions asume that you have a development environment ready to run KOReader. If not then please install common prerequisites first.

A toolchain for your target.

Each target has its own architecture and you'll need to setup a proper cross-compile toolchain. Your GCC should be at least version 4.9.

for Android

If you want to use your own NDK / SDK installs, the build system honor the standard environment variables:

• NDK location: ANDROID_NDK_HOME or ANDROID_NDK_ROOT
• SDK location: ANDROID_HOME or ANDROID_SDK_ROOT

Otherwise, compatible versions of the Android NDK and SDK will be downloaded and setup automatically (under base/toolchain) as part of the build.

NOTE: If you want to use your own installed tools, please make sure to use the following supported versions: NDKr23c and the SDK for Android 9 (API level 28).

for embedded Linux devices

Cross compile toolchains are available for Ubuntu users through these commands:

e-Ink devices (e.g., Kindle, Kobo, Cervantes, reMarkable, PocketBook)

NOTE: While, for some targets (specifically, Cervantes, Kindle & Kobo), we make some effort to support Linaro/Ubuntu TCs, they do not exactly target the proper devices. While your build may go fine, this will probably lead to runtime failure.
As time goes by, and/or the more bleeding-edge your distro is, the greater the risk for mismatch gets.

Which means, that, unless you are very sure you know what you're doing, you'll want to use the exact same TCs we do, ones that target their respective platforms properly.
We have a distribution-agnostic solution to make that mostly painless: koxtoolchain!
This will allow you to build the exact same TCs used to build the nightlies, thanks to the magic of crosstool-ng. These are also included precompiled in the Docker images for the respective targets.

Additional packages

Some platforms will require additional packages:

for Android

Building for Android requires openjdk-17-jdk-headless and p7zip-full.

For both Ubuntu and Debian, install the packages:

sudo apt-get install openjdk-17-jdk-headless p7zip-full

for Debian

Building a debian package requires the dpkg-deb tool. It should be already installed if you're on a Debian/Ubuntu based distribution.

Building

You can check out our nightlybuild script to see how to build a package from scratch.

Android

./kodev release ANDROID_TARGET

Where ANDROID_TARGET is one of the supported targets:

• android-arm
• android-arm64
• android-x86
• android-x86_64

Desktop Linux

Emulator

See Building.

AppImage (x86_64)

./kodev release appimage

Debian (x86_64)

./kodev release debian

Debian (armel)

./kodev release debian-armel

Debian (armhf)

./kodev release debian-armhf

Desktop macOS

./kodev release macos

e-Ink devices

Cervantes

./kodev release cervantes

Kindle

./kodev release kindle

Kobo

./kodev release kobo

Pocketbook

./kodev release pocketbook

reMarkable

./kodev release remarkable

Porting to a new target.

See Porting.md