CONFIG_XILINX_VIRTEX_4_FX is not available for thedefaultarchitecture x86.
Result is shown for architecture ppc
CONFIG_XILINX_VIRTEX_4_FX (not configurable)
configname: CONFIG_XILINX_VIRTEX_4_FX
Linux Kernel Configuration
└─>IBM 4xx options
└─>XILINX_VIRTEX_4_FX