Next, we need to create subdirectories for each of the three groups of cross-development tools. When using the Cygwin bash shell, the “/” refers to the root Cygwin installation directory, which in our case is D:\cygwin. To create the necessary directories, enter the following command:
$ mkdir –p /src/binutils /src/gcc /src/gdb
Verify that these directories are created correctly under the D:\cygwin root directory.