newlib with stock mingw GCC wihtou cross compile?

[Chris Schanck <chris at schanck dot net>]

Sorry if this is an odd request....

What I would like to do is use newlib in place of glibc with an existing 
MinGW GCC install, preferably simply via command line switches. I would 
also like to do this on linux, with an existing gcc install .

So far I am able to compile newlib pretty easily, and compiling libgloss 
gives me libnosys as expected.

Here I find myself at a fork in the road. Is what I am trying to do 
possible without writing a signifigant chunk of code, or should I just 
go ahead and make a complete cross compiler? So far any attempts to 
'slide' newlib into the existing Gnu chain have not worked well at all.

The goal is to be able to modify newlib so I can catch any IO requests  
(open/read/write/close) and possibly (depending on the device) take 
alternative action for a testbench environment I am playing with.

Any thoughts would be appreciated.

Chris