Using GCCSDK

= Using GCCSDK and Autobuilder to cross-compile for RISC OS =

Building the cross-compiler
''The previous version of these instructions referred to the use of the GCC 3.4.6 cross compiler. Due to ongoing development, using GCC 3.4.6 may no longer work with all Autobuilder packages. The focus is now on the GCC 4.7.x (stable) or GCC 4.1.2 (deprecated) cross compiler with the Autobuilder.''

Cross-compiling for RISC OS is done by using GCCSDK on a Unix-alike host system, such as GNU/Linux, FreeBSD, Solaris, MacOS X or even Windows (under Cygwin). To get started, ensure you have a Subversion client installed for your system, and fetch the GCCSDK source and Autobuilder infrastructure to the current directory:

In case you want to use the stable cross-compiler (based on gcc 4.7.x):

$ mkdir gccsdk $ cd gccsdk $ svn co svn://svn.riscos.info/gccsdk/trunk/autobuilder/ autobuilder $ svn co svn://svn.riscos.info/gccsdk/trunk/gcc4/ gcc4

In case you want to use old (deprecated) cross-compiler (based on gcc 4.1.2):

$ mkdir gccsdk $ cd gccsdk $ svn co svn://svn.riscos.info/gccsdk/trunk/autobuilder/ autobuilder $ svn co svn://svn.riscos.info/gccsdk/branches/release_4_1_2/ gcc4

Build the cross compiler and follow the prompts:

$ cd gcc4 $ ./build-world

When build-world is run for the first time, it will ask you to confirm the settings in the created file gccsdk-params. Note that its default settings are installing the cross-compiler at gccsdk/gcc4/cross (known as the parent directory of GCCSDK_INSTALL_CROSSBIN) and all with the cross-compiler built RISC OS libraries, binaries and included files in gccsdk/gcc4/env (known as GCCSDK_INSTALL_ENV). More detailed help can be found in the README file in the gcc4 directory.

It may ask you to install additional tools. The full list is as follows (the first 6 entries are likely not installed with standard distributions):


 * autogen v5.5.4 (or later)
 * m4 v1.4.16 (or later)
 * makeinfo : version 4.8 (Debian package is 'texinfo')
 * gcc and g++ : v3.4.x or v4.x.y
 * bison: version 2.3 (other versions might work too)
 * flex : version 2.5.4 (other versions might work too)
 * svn (subversion) : version 1.2 or later
 * bash
 * gperf : version 2.7.2
 * sed : version 2.05
 * GNU make : version 3.81 (other versions might work too)
 * libtool : version 1.5.22 (other versions might work too)
 * patch	: version 2.5.9 (other versions might work too)
 * wget
 * help2man

For Ubuntu 14.04, install these packages (for GCC and autobuilder):

libtool patch wget help2man autogen m4 gcc g++ bison flex subversion gperf sed make build-essential autoconf2.13 automake automake1.9 automake1.11 cvs doxygen dpkg-dev gettext intltool libglib2.0-dev liborbit2-dev libpopt-dev pkg-config policykit-1 realpath rman subversion unzip wget xsltproc texinfo git libx11-dev tcl

Other non-essential packages that are needed for specific autobuilder packages:

fontforge dos2unix texi2html libfreetype6-dev libfont-ttf-perl

You will also need CVS installed, in order to fetch the binutils source - build-world does not check for this dependency, so your build will fail later if it is missing. http://sourceware.org/ml/binutils/2011-08/msg00198.html

Then run build-world again:

$ ./build-world

Depending on your hardware, this may take a long time to complete. If this all went ok, then the cross compiler has been built successfully, and you can proceed to use the Autobuilder. If anything went wrong, or you want to build the RISC OS port of GCC, consult the README file for more detailed instructions.

Using the cross-compiler
The autobuilder is a way to fetch and cross-compile software from other platforms automatically. If you want to use the tools to develop new software, or to port a new program to RISC OS (which you might later put in the autobuilder), first see the Cross-compiling Guide.

Autobuilder requirements
The Autobuilder will have already been checked out in the above instructions and lives in the directory gccsdk/autobuilder. You should not try to build from within that directory. Under the gccsdk directory, create an additional directory build.

$ cd ../ $ mkdir build

You will then have these directories in the gccsdk directory:


 * autobuilder (Autobuilder files)
 * build (Build work directory)
 * gcc4 (Cross compiler source)

The Autobuilder contains a number of programs with quite complex build systems, and has some additional requirements itself which need to be present on the build system. They are the following:


 * autoconf2.13
 * automake
 * automake1.7
 * cvs
 * doxygen
 * dpkg-source (Debian 6, dpkg-dev)
 * gettext (for xgettext)
 * git
 * intltool (for intltoolize)
 * libglib1.2-dev (not in Debian 6, try libglib2.0-dev)
 * liborbit-dev (Debian 6, liborbit2-dev)
 * libpopt-dev
 * libx11-dev
 * pkg-config
 * policykit (for polkit-policy-file-validate)
 * realpath
 * rman
 * svn
 * unzip
 * wget
 * xsltproc

These are the names of Debian's packages for them, other distributions may vary (for example, see the Cygwin page). We strongly recommend that these packages are installed before using Autobuilder, as their absence can lead to wasted time trying to identify the potential resulting problems.

The availability of these programs is checked as needed by the Autobuilder, and they aren't all required for simple builds.

Source code
Fetching the source code of the open-source programs are done via different methods like apt-get, ftp, http, svn, cvs, etc. Historically, the Autobuilder relied upon running on Debian and using the local machine's apt list of sources. This can still be done, but the Autobuilder by default will fetch the source lists itself and download from its own copies. This means it can run on any Linux or Unix setup (including Cygwin).

Most sources are pulled from Debian testing, but the Autobuilder might fall back to stable for some packages. Other packages may use alternate download methods where the source does not exist in Debian, or we desire a specific version.

Simple Autobuilder example
Now use the Autobuilder to build a package:

$ cd build $ ../autobuilder/build -v wget

This will attempt to build the wget package in your build directory. For any package, the Autobuilder will first try to build the package's dependencies. In this case, there are a few. For instance, a special RISC OS specific version of 'zip' to run on the cross compiling system which understands RISC OS filetype conventions under Unix in order to usefully package the result. The wget package also relies upon the zlib library (zlib1g) and the OpenSSL library (libssl1.0.2), so these will be built too.

The work is done under a created wget subdirectory. If the build is successful this will be deleted and the results placed in ../autobuilder/autobuilder_packages. This is a zip file which can be copied to RISC OS to be unpacked and run (it's actually a RiscPkg package). If not successful, the wget directory in build will remain for you to inspect. The output from the build process is also saved in ../autobuilder/network/wget as either a file last-success or last-failure depending on what happened.

See the developing for Autobuilder page for complete details.

A more complex Autobuilder example
There are many more packages and libraries in the Autobuilder, too many to list here. Most of the programs in the Unix Porting Project are represented here. Many of these contain dependencies, which means they will instruct other packages to be built first before they can be built.

The method for building them is precisely the same. For example:

$ ../autobuilder/build -v firefox2 -D

This will build a version of Mozilla Firefox 2 for RISC OS (see its setvars file to know which version is selected). Note that this has many dependencies and could take some hours depending upon your hardware and network connection.

If you want to retain the source to a package (e.g. for debugging or development), simply use the  flag alongside the   flag as in the example here.

Using ChoX11 with the Autobuilder
Any program in the Autobuilder which has dependencies upon the X libraries will also require ChoX11 and DeskLib (which ChoX11 uses) to be built. The Autobuilder will instruct the linker to automatically replace library references to the X11 library with ChoX11 and DeskLib.

Troubleshooting
See also: GCCSDK build debugging tips

Most problems with using the Autobuilder come from one of three sources:
 * Missing packages on your build Unix system
 * Out of date installation of GCCSDK/Autobuilder
 * Upstream changes

If you have an error about missing files when trying to build something, it's most likely that there's something missing from your build Unix system. Try searching your distribution to find out which package these files are installed in: try the 'search within packages' for Debian if you use those, or a similar facility for your build OS.

If you think you've got all the files (ask the GCCSDK list if you aren't sure), it's worth a try to rename /home/riscos to something else and run through these instructions from scratch: this will ensure te latest latest compilers and libraries are used.

If neither of those have any luck, there have probably been upstream changes. Ideally it's best to fix the Autobuilder and/or libraries so the newer upstream will build, but otherwise you can look at the setvars file and tweak it so it fetches older sources (from a specific tarball, instead of CVS, for example). Look at a few setvars files to see how this syntax works.

If you still have trouble, ask on the GCCSDK mailing list. Also if you manage to get anything to build, or spot things which have broken, do inform the list or submit patches.

Help wanted
Ideally, all projects in the Autobuilder can be built with a single command. In practice at any one time there are a few packages which need attention. However, in this state, it is generally minimal effort to update a package to the latest version.

In order to achieve this, we need help in the follow areas:


 * Simply testing of builds. In most cases, the developers can fix issues quickly.
 * Complete packaging. Many packages are now uploaded in a RiscPkg format, but this work is still on going.
 * Bringing up to date abandoned RISC OS ports from other developers, and added them to the Autobuilder.
 * It would be great to have a port of Mesa and particular IyonixMesa in Autobuilder as it would all kind of OpenGL based programs to be ported.
 * Flash support: either Gnash (talk to John-Mark Bell as he already did some work), either Swfdec.
 * Gnumeric : well known open-source spreadsheet.
 * Pidgin : previously known as GAIM is a GTK+ instant messaging application. It supports multiple protocols, including AIM, ICQ, Yahoo!, MSN, Jabber, IRC, Napster, Gadu-Gadu, Zephyr, and SILC.

Discussions, questions, new ideas or just a statement you're want to help here can be done in GCCSDK mailing list.

Links

 * An excellent tutorial on GNU Autotools can help you understanding how most packages are configured using the GNU Autotools and built in Autobuilder.
 * Autotools Mythbuster : Handy set of notes for autoconf, automake, libtool.
 * The Goat Book (GNU Autoconf, Automake and Libtool)