There are two solutions:
- Add -Wno-builtin-declaration-mismatch in the Other flags setting of the MCU GCC Compiler Miscellaneous tab
- Correct the eCos declarations to match the standard
The first solution is simple, but may mask real errors. The second is longer but safer; however you will have to correct eCos code after each eCos update (unless you are able to submit the correction to eCos...), something that would be simpler if you manage the eCos code under SVN or GIT as updates will retain your corrections.
Hope this helps,