A problem when cross compile?

I write a simple “hello world” c program,and in linux using the following command

code:# nios2-linux-uclibc-gcc -elf2flt -o hello hello.c# file hello

hello : data

why the format of \"hello\" isn\'t flat ? I download it to uclinux,and run ./hello ,it outputs \"permission dennied\",so what\'s my problem ? the excutable format on uclinux is flat,isn\'t it?