How could I get a working RTEMS source?

[open_sky]

hi,

I have downloaded the sources needed to create the cross compiler for rtems-4.5.0-beta1b from www.oarcorp.com/rtems/beta/rtems-4.5.0-beta/src, and built it successfully. But I could only get the rtems-4.5.0-beta1c.tgz from that site, and it doesn't work!!!

I also downloaded all sources needed to build the cross compiler for rtems-4.5.0 and itself, but it also couldn't  be built successfully for all options, even if I built them successfully when I made some modification in a Makefile.in and  switched the posix ,TCP/IP and test options off.  

Could you help me in the following aspects:
----tell me a site to download rtems-4.5.0-beta1b.tgz 
or
----tell me a way and needed sources to build rtems-4.0.0


Sincerely,


James Zhang(zjw)
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