Below is a sample ~/.jhbuildrc  file to cross compile build X.  Replace arm-none-linux-gnueabi with your toolchain.    It assumes that you have export'ed DISCIMAGE  to where you want to install to.

{{{#!python
#######################################################################################
# This is a checkout and build configuration for building Xorg
#
# This can be copied to ~/.jhbuildrc  and then run 'jhbuild build xserver'
#
#######################################################################################

moduleset = 'http://cgit.freedesktop.org/xorg/util/modular/plain/xorg.modules'
checkoutroot = '~/sources/xorg/git'
modules = [ 'xorg' ]
prefix = os.environ['DISCIMAGE'] +'/usr/local'

autogenargs = ' --disable-static'
autogenargs += ' --disable-dri2 --with-driver=dri'
autogenargs += ' --cache-file=' + checkoutroot + '/autoconf-cache'
# lots of people really like to always look in /var/log, but change if
# you want the log files out of place
autogenargs += ' --with-log-dir=/var/log'
autogenargs += ' --with-mesa-source=' + checkoutroot + '/mesa'
autogenargs += ' --enable-malloc0returnsnull'

os.environ['ACLOCAL'] = 'aclocal -I ' + prefix + '/share/aclocal/'
os.environ['INSTALL'] = os.path.expanduser('~/bin/install-check')

# Enabled debugging for xserver
os.environ['CFLAGS'] = '-g'
os.environ['CPPFLAGS'] = '-g'

# Setup environment for cross compiling

os.environ['BUILD'] = 'i686-pc-linux-gnuaout'
os.environ['HOST'] = 'arm-none-linux-gnueabi'
os.environ['TARGET'] = 'arm-none-linux-gnueabi'

cross_compile_prefix = os.environ['CROSS_COMPILE']
tools = {'ADDR2LINE': 'addr2line',
	'AS': 'as', 'CC': 'gcc', 'CPP': 'cpp',
	'CPPFILT': 'c++filt', 'CXX': 'g++',
	'GCOV': 'gcov', 'LD': 'ld', 'NM': 'nm',
	'OBJCOPY': 'objcopy', 'OBJDUMP': 'objdump',
	'READELF': 'readelf', 'SIZE': 'size',
	'STRINGS': 'strings', 'AR': 'ar', 
        'RANLIB': 'ranlib', 'STRIP': 'strip'}

tools_args = str()
for tool in tools.keys():
	fullpath_tool = cross_compile_prefix + tools[tool]
	os.environ[tool] = fullpath_tool

autogenargs += ' --build='+os.environ['BUILD']
autogenargs += ' --host='+os.environ['HOST']
autogenargs += ' --target='+os.environ['TARGET']

for tool in ('AR', 'RANLIB', 'STRIP', 'AS', 'OBJDUMP', 'NM'):
	autogenargs += ' '+tool+'="'+os.environ[tool]+'" '

module_autogenargs['libGL'] = autogenargs + ' --without-demos --with-dri-drivers="swrast" --disable-glw'
module_autogenargs['libXt'] = autogenargs + ' --disable-install-makestrs'
module_autogenargs['xserver'] = autogenargs + ' --enable-debug'
module_autogenargs['pixman'] = autogenargs + ' --disable-gtk'
module_autogenargs['hal'] = autogenargs + ' --disable-pci-ids'
module_autogenargs['libXfont'] = autogenargs + ' --disable-freetype'

# For expat and zlib
os.environ['CFLAGS'] += ' -I' + os.environ['DISCIMAGE'] + '/usr/local/include/'
os.environ['CPPFLAGS'] += ' -IHello -I' + os.environ['DISCIMAGE'] + '/usr/local/include/'
os.environ['LDFLAGS'] = ' -L' + os.environ['DISCIMAGE'] + '/usr/local/lib/'
os.environ['LDFLAGS'] += ' -Wl,--rpath -Wl,' + '/usr/local/lib/'  #rpath is relative to where it is run from - DISCIMAGE 

# Just in case zlib or expat were installed here
os.environ['CFLAGS'] += ' -I' + os.environ['DISCIMAGE'] + '/usr/include/'
os.environ['CPPFLAGS'] += ' -I' + os.environ['DISCIMAGE'] + '/usr/include/'
os.environ['LDFLAGS'] += ' -L' + os.environ['DISCIMAGE'] + '/usr/lib/'
os.environ['LDFLAGS'] += ' -Wl,--rpath -Wl,' + '/usr/lib/'
}}}