Modifying the std C libraries

Modifying the std C libraries

[Rick Mann]

We've got an xscale-elf cross compiler built using binutils, gcc 4,  
and newlib. It all seems to work reasonably well. Now we've reached a  
point where we must strip out all uncalled source code from newlib,  
and rebuild that.

I tried the experiment of building a new newlib with the xscale-elf  
tools, which worked fine, and then making a simple test program that  
linked against printf(), then removing printf() and rebuilding newlib  
and relinking. I would expect it to fail, but it doesn't.

I wonder if GCC is implicitly linking against the newlib that was  
built with it, rather than my new newlib (even though i specify -I and  
-L and -lc).

How can I get GCC to ignore the stuff it would normally implicitly  
link against and instead link against a very specific version of the  
runtime libs?

TIA,
-- 
Rick

Re: Modifying the std C libraries

[Brian Dessent]

Rick Mann wrote:

> How can I get GCC to ignore the stuff it would normally implicitly
> link against and instead link against a very specific version of the
> runtime libs?

Use '-nodefaultlibs' if you don't want the standard libs,
'-nostartfiles' if you don't want the standard startup files, and
'-nostdlib' if you don't want either.   Note the blurb in the manual
about -lgcc if you use these.

Brian