I have not been able to get readline 5.1 to compile with the ELDK - it places the value of CROSS_COMPILE in the gcc command line and thus fails with "No such file or directory". I emailed the readline maintainer and got this response:
"The bash Makefiles expect CROSS_COMPILE to expand to a preprocessor option, and will fail otherwise." I can make it work with a hack, but I thought this might be interesting info. Any comments? Lee