In order to be built, XEOS needs a custom version of the LLVM compiler.
The reason for this is that the compilers available by default on standard systems may only compile executables of a specific format.
For instance, you won't be able to build ELF on Mac OS X, nor Mach-O executables on Linux, using the default compilers.
Additionally, the default compilers will usually automatically link with the standard C library that is available on the running system.
As XEOS is itself an operating system, it won't be able to use such a library.
So the first step, in order to compile XEOS, is to compile the compiler that will be able to compile it...
And of course, a compiler needs to be available on your system in order to compile a version of LLVM.
It may seems funny, but don't worry: everything has been prepared for you.
From a terminal window, you need to cd to XEOS trunk's directory.
Then, type the following command:
make toolchain
It will download the LLVM sources and build everything that's needed to compile XEOS.
Everything will be installed in the «/usr/local/xeos/» directory, so you can easily clean everything up when needed.
The build process may take some time. But once it's done, you are ready to compile and use XEOS.
Compiling XEOS is a very simple task.
From the trunk's directory, simple type the following command:
make
It will generate a FAT-12 floppy disk image containing the full OS, that you can run on any x86 or x86_64 machine or emulator.
XEOS can be run with emulators, like VirtualBox.