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Re: position independent code


Scott Howard wrote:

> Gnu CC does support position independant code with the -fpic and -fPIC
> options.  It is only supported when the compiler & assembler use the ELF
> object file format, it does not work when using COFF (as you have
> already discovered, judging from the listing you enclosed).  ELF for the
> m68k will be supported in a forthcoming release of EGCS.
>
> There is an additional complication: the gnu implementation is designed
> with shared libraries in mind; it creates an address translation table
> which must be 'fixed up' at run time to point to the absolute address of
> functions and variables.  This is not really useful for an embedded
> (diskless, OS-less) system.  This is a more complicated issue, and it
> would take some work to implement for a low-end system (essentially you
> would need a run-time loader of some sort).
>

I is VERY useful for embedded systems, especially if your embedded system
needs a run-time loader, and is networked.   The loader is then trivial.

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