Difference between revisions of "Compiling ScummVM/RPI"

It will get cloned to a directory called ''tools'' at your current location.

Add it to the ''PATH'' environment variable so that we have the cross-compiler binaries available from our scummvm building directory. For example, if my Raspberry Pi ''tools'' repository ended cloned in ''tools'' under my ''home'' directory, I would do:

After adding the cross-compiler executables directory to ''PATH'', we should be able to run ''arm-linux-gnueabihf-gcc'', ''arm-linux-gnueabihf-g++'', etc... just try. They should yield an error because you pass them no input files, but that's expected. It's just a test so we know we have the cross-compiler installed and accessible.

We need to copy over the '''/usr''', '''/lib''' and '''/opt''' directories from your Raspbian SD Card to your '''host PC''' (the computer where you will do the cross-compilation) for the needed headers and libraries to be available.

Of course, first you'll have to install any additional libraries from Raspbian running on the Pi before expecting them to be available so, if you want compile ScummVM with FLAC support, you should have installed the libflac development libraries on the Pi beforehand.

On the '''host PC''' we first export the path where we will copy these into, and then we manually copy them. I choose to copy the Raspberry Pi headers and libraries to ''/opt/rpi_root'', but any other path with the right permissions for your user (within common sense) should be ok:

First, you should make sure have the latest version of the ScummVM code locally (using ''git clone'' or ''git pull'' appropriately).  

Then, navigate inside your local ''scummvm'' source code folder.

Now we can configure ScummVM buildsystem so it knows what backend we target and where our Raspberry Pi ''local sysroot'' is located, containing the Raspberry Pi headers and libraries the cross-compiler and linker will need. In this example configuration, we disable debug symbols since it's intended for final users.

Remember you should have exported the ''RPI_ROOT'' environment variable previously and updated the ''PATH'' environment variable to be preceded by the ''RPI_ROOT'' path and succeeded by the path to the Raspberry Pi toolchain bin folder (as shown in the previous steps).

Unfortunately, the official toolchain for cross-compiling for Pi is, as of yet, using an old ''gcc'' version (4.3.9) and hence, the configure script may fail to detect the ''FluidSynth'' library specifically. FluidSynth and MT-32 emulation are features that are very demanding on CPU processing power so it should be ok to skip them entirely. Alternatively, you could seek out a more up-to-date ''armhf'' toolchain for the cross-compilation, such as this [https://github.com/Pro/raspi-toolchain/releases Raspberry Pi toolchain by Stefan Profanter (Pro)] which, in its 1.0.1 version, uses ''gcc'' version 8.3.0 and reportedly "supports all new Raspberry PIs (ARMv7), and the older ones, including Zero, A, B, B+ (ARMv6) with newer GCCs."

'''Note 1:''' If you use the Raspberry Pi toolchain by Stefan Profanter (Pro), then make sure you read the instructions from the README file ([https://github.com/Pro/raspi-toolchain also available from the main page of the repository]). Specifically, this toolchain needs to be installed in ''/opt/cross-pi-gcc'' since it's not location independent.

'''Note 2:''' If you are building ScummVM directly on your Raspberry Pi itself, you might run out of memory during the final linking process of the build. If you use GNU ''ld'' for compiling, you could execute the following before running ''configure'':

This tells GNU ''ld'' to optimize for memory usage.

Run the following commands:

Simply copy over the resulting ''scummvm'' executable to your Raspberry Pi (Raspbian OS) SD Card. A good idea is to create a ''scummvm'' folder in your ''/home/pi'' directory on the Raspian OS SD Card, and put the executable there along with any games you want to use with it.

In order to have the text-to-speech feature available for ScummVM you should also install the speech-dispatcher package and a text-to-speech engine (as per the instructions in this pertinent [https://github.com/scummvm/scummvm/pull/1808 Pull Request])

For example you'd need to execute the following on your Raspbian OS on the Pi in order to use the espeak-ng text-to-speech engine: