I wrote some documentation on how to build a gdc cross-compiler: http://gdcproject.org/wiki/Cross%20Compiler
For now there's only a tutorial describing how to use crosstool-NG with gdc, but crosstool-NG already supports many different configurations: http://gdcproject.org/wiki/Cross%20Compiler/crosstool-NG crosstool-NG allows to build cross compilers for these architectures: Alpha, ARM, AVR32, Blackfin, MIPS, OpenRISC/or32(+), PowerPC, s390, SPARC, SuperH, x86 Supported C libraries: uclibc, eglibc, glibc, mingw, newlib Supported OS: linux, windows, bare-metal Some configurations probably won't work with gdc right now, windows/mingw builds probably need additional patches to be usable. crosstool-NG also allows to build canadian-cross compilers, where the build machine != host machine != target machine. For example this allows to build a cross compiler on Linux/x86-64 which runs on Windows/x86 and compiles code for Linux/ARM.