build-FreeFileSync-on-raspberry-pi

FreeFileSync is a great open source file synchronization tool. Building from source on linux is straightfoward if all the necessary dependencies are installed. These instruction capture the necessary steps for installing the necessary dependencies and compiling FreeFileSync on 32-bit Raspberry Pi OS (formerly referred to as Raspbian)

This version of instruction apply to the following:

Item	Release/Version
Raspberry Pi OS (Raspbian)	`Release 4.2 Mar 2022`
FreeFileSync	`v11.21`

1. Download and extract the FreeFilesSync source code

As of this writing, the latest version of FreeFileSync is 11.21 and it can be downloaded from:

https://freefilesync.org/download/FreeFileSync_11.21_Source.zip

For some reason, wget DID NOT successfuly download the file on the first try (instead it downloads a portion and silently exits). Simply try the wget command a second time or you can manually download it through a browser.

Move the .zip file to the desired directory and uncompress unzip FreeFileSync_11.21_Source.zip

2. Install available dependencies via apt-get

These instructions reflect building FreeFileSync using libgtk-3. This may lead to a non-optimal user experience- see: https://freefilesync.org/forum/viewtopic.php?t=7660#p26057

The following dependencies need to be installed to make the code compile.

libgtk-3-dev
libxtst-dev
libssh2-1-dev

sudo apt-get update
sudo apt-get install libgtk-3-dev 
sudo apt-get install libxtst-dev
sudo apt-get install libssh2-1-dev

3. Compile dependencies not available via apt-get

The following dependencies could not be installed via apt-get and need to be compiled from their source code.

3.1 gcc w/ good C++20 support

FreeFileSync requires good support of the C++20 standard and often takes advantage of the latest refinements once available across the major compilers (see https://freefilesync.org/vision.php for some background). As such, if you want to compile FreeFileSync on Raspberry Pi OS, you'll need a fresh version of gcc (the default version of gcc with RaspberyPi OS will not have all the necessary support).

For FFS v11.21, you'll need at least gcc 12.1.0

Follow the instruction at: https://www.raspberrypi.org/forums/viewtopic.php?t=239609 to build and install the gcc 12.1.0 with minor modifications. See build_gcc.sh for the script with only C/C++ languages enabled. Before running, be sure to review and update the config in build_gcc.sh according to your device (default is Raspberry Pi 4).

Note the build needs about 8 GB of free disk space and takes about 4 hours on the Raspberry Pi 4 (4 GB), over 6 hours on the Raspberry Pi 3B+ and over 50 hours on the Raspberry Pi Zero.

sudo chmod +x build_gcc.sh
sudo bash build_gcc.sh

If you follow the steps correctly, you should see the new version:

g++ --version

Expected result:

g++ (GCC) 12.1.0

To ensure FreeFileSync can find the necessary libraries during runtime, copy the newly created libstdc++ lib to a standard Raspberry Pi OS location

sudo cp /usr/local/lib/libstdc++.so.6.0.30 /lib/arm-linux-gnueabihf/
sudo ldconfig

3.2 openssl

Starting with FreeFileSync 11.14, use of openssl 3.0 is supported so build OpenSSL 3.0 and make it available to use.

wget https://www.openssl.org/source/openssl-3.0.0.tar.gz
tar xvf openssl-3.0.0.tar.gz
cd openssl-3.0.0
mkdir build
cd build
../config
make
sudo make install
sudo ldconfig

3.3 libcurl

Installed the version of curl (curl v7.83.0) as suggested in the Bugs.txt file

wget https://curl.se/download/curl-7.83.0.tar.gz
tar xvf curl-7.83.0.tar.gz
cd curl-7.83.0/
mkdir build
cd build/
../configure --with-openssl --with-libssh2 --enable-versioned-symbols
make
sudo make install

3.4 wxWidgets

Starting with FreeFileSync v11.20, the minimum version for WxWidgets is 3.1.6. Build instructions are:

wget https://github.com/wxWidgets/wxWidgets/releases/download/v3.1.6/wxWidgets-3.1.6.tar.bz2
tar xvf wxWidgets-3.1.6.tar.bz2
cd wxWidgets-3.1.6/
mkdir gtk-build
cd gtk-build/
../configure --disable-shared --enable-unicode
make
sudo make install

4. Tweak FreeFileSync code

Even with the needed dependencies, some code tweaks are needed (see BUGS.txt in the top-level directory for a complete reference)

4.1 FreeFileSync/Source/afs/sftp.cpp

Add these constant definitions starting at line 25

#define MAX_SFTP_OUTGOING_SIZE 30000
#define MAX_SFTP_READ_SIZE 30000

4.2 Update FreeFileSync/Source/Makefile to use GTK3 instead of GTK2

Although as mentioned previously, use of GTK3 can result in poor UI experience (see thread at: https://freefilesync.org/forum/viewtopic.php?t=7660) the various dependencies for GTK2 building became too arduous for Raspbery Pi OS and so, picking my poison, I switched to GTK3.

On line 19:

change: cxxFlags  += `pkg-config --cflags gtk+-2.0`
to:     cxxFlags  += `pkg-config --cflags gtk+-3.0`

On line 21:

change: cxxFlags  += -isystem/usr/include/gtk-2.0
to:     cxxFlags  += -isystem/usr/include/gtk-3.0

4.2.1 Update FreeFileSync/Source/Application.cpp to update old filepath parsing

It looks like the code that supports finding and loading the gtk3 css file didn't get updated when some of the underlying path handling functions got revised in v11.21

On line 96:

change:  (getResourceDirPf() + fileName).c_str(), //const gchar* path,
to:      (appendPath(getResourceDirPath(),fileName)).c_str(), //const gchar* path,

4.3 [Optional] FreeFileSync/Source/Makefile

To make the exectuable easier to run, add after line 28:

LINKFLAGS += -Wl,-rpath -Wl,\$$ORIGIN

4.4 [Optional] Populate Google client_id and client_key in Freefilesync/Source/afs/gdrive.cpp

Information about Google Drive support on self-compiled instances was mentioned at https://freefilesync.org/forum/viewtopic.php?t=8171

If you set up your own Google project with its own Client ID and Client Secret (free for personal testing/use), add that information in between the " " on lines 89 and 90:

std::string getGdriveClientId    () { return ""; } // => replace with live credentials
std::string getGdriveClientSecret() { return ""; } //

5. Compile

Run make in folder FreeFileSync_11.21/FreeFileSync/Source.

Assuming the command completed without fatal errors, the binary should be waiting for you in FreeFileSync_11.21/FreeFileSync/Build/Bin.

6. Run FreeFileSync

Go to the FreeFileSync_11.21/FreeFileSync/Build/Bin directory and enter:

./FreeFileSync_armv7l

Running FreeFileSync on another Raspberry Pi {UNTESTED/UNVERIFIED for v11.20}

You don't need to build anything again on the other Raspberry Pi hosts but you will need to copy over the various libraries and other dependencies so the executable can run. Compilation made and tested on Raspberry Pi 4 w/4GB RAM using clean updated Raspberry Pi OS on 22.11.2020

1. Create zip file with executable and all dependencies

Once the executable binary has been created and verified working, copy all dependency libraries to the same folder as the binary, then copy the Build/Resources folder, then zip them all up in a file.

The shared libraries that need to be copied are:

libssl.so.3
libstdc++.so.6
libcurl.so.4
libgcc_s.so.1
libcrypto.so.3
libssh2.so.1

Then end zip file should look like this:

Archive:  FreeFileSync_11.4_armv7l.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  2020-04-27 22:38   Bin/
  9074216  2020-04-27 22:35   Bin/FreeFileSync_armv7l
   560412  2020-04-17 13:40   Bin/libssl.so.3
 17574572  2020-04-10 15:12   Bin/libstdc++.so.6
   492832  2020-04-17 14:14   Bin/libcurl.so.4
  7543332  2020-04-10 15:10   Bin/libgcc_s.so.1
  3476740  2020-04-17 13:40   Bin/libcrypto.so.3
   961484  2020-04-17 14:07   Bin/libssh2.so.1
      349  2020-03-18 21:57   FreeFileSync.desktop
        0  2020-03-18 21:57   Resources/
      234  2020-03-18 21:57   Resources/Gtk3Styles.css
    12402  2020-03-18 21:57   Resources/RealTimeSync.png
   182060  2020-03-18 21:57   Resources/harp.wav
    87678  2020-03-18 21:57   Resources/bell2.wav
    13232  2020-03-18 21:57   Resources/FreeFileSync.png
   223687  2020-03-18 21:57   Resources/cacert.pem
      440  2020-03-18 21:57   Resources/Gtk2Styles.rc
    67340  2020-03-18 21:57   Resources/ding.wav
   143370  2020-03-18 21:57   Resources/bell.wav
   230274  2020-03-18 21:57   Resources/gong.wav
   388959  2020-03-18 21:57   Resources/Icons.zip
   522150  2020-03-18 21:57   Resources/Languages.zip
    55006  2020-03-18 21:57   Resources/notify.wav

Now the zip file should contain all the dependencies and the binary Bin/FreeFileSync_armv7l is able to run on a new raspberry pi assuming the target is running a current verions of Raspbian.

2. On target host, copy and extract the zip archive you created

extract to:

/home/pi/Desktop/FFS_11.4_ARM/

3. Copy all lib* files to /usr/lib

sudo cp /home/pi/Desktop/FFS_11.4_ARM/Bin/lib* /usr/lib
sudo ldconfig

4. Run FreeFileSync

Go to /home/pi/Desktop/FFS_11.4_ARM/Bin/

./FreeFileSync_armv7l

Troubleshooting & Known Issues

Error due to missing shared libraries

./FreeFileSync_armv7l: error while loading shared libraries: libssl.so.3: cannot open shared object file: No such file or directory

sudo cp /home/pi/Desktop/FFS_11.3_ARM/Bin/lib* /usr/lib
sudo ldconfig

Other issues could exist

Other issues could certainly exist as overall usage of FreeFileSync on Raspberry Pi is presumably small. It seems likely there could be issues with the more demanding or complex use-cases.

JensKapitza/build-FreeFileSync-on-raspberry-pi