Build rtems-4.0.0 on windows NT with cygwin-b20

[guobing]

Hi,folks!I download rtems-4.0.0,gcc-2.8.1,binutils-2.9.1,newlib-1.8.0 and GNAT for windows.I want to build a rtems cross development system(use ADA,C and C++ language) on windwos NT 4.0 with cygwin-b20.When I run ./bit_ada i386,an error occurs.The error message is showned as follows:

Configuring for a i686-pc-cygwin32 host.
./../src/opcodes/../ltconfig: ../../src/opcodes/../ltconfig: No such file or directory
configure: error: libtool configure failed
Configure in /user/ada/build-i386-tools/opcodes failed, exiting.
make[1]: *** No rule to make target `../../src/libiberty/../include/libiberty.h', needed by `argv.o'.  Stop.
make: *** [all-libiberty] Error 2
ERROR: **** FAILED **** base build of C and C++ (step 1)

Anyone can help me?Another question.Where and how to download snapshot of rtems?Thanks.