Re: 16-bit relocations in 32-bit code

[Andrew Zabolotny <zap at homelink dot ru>]

From Mon, 15 Mar 2010 12:44:26 -0700
Richard Henderson <rth@redhat.com> wrote:

> There is no solution that is generally portable.
I understand, but I can live with platform-specific macros.

> However, given the existance of R_386_PC16, you should be able to
> represent ".short SYM-." for any SYM on both i386 and x86_64.
I don't quite get the idea. ".short SYM-." won't generate any
relocation at all, how this can help me? But I tried a simple example
like this:

        .reloc  .,R_386_PC16,PLUS
        .short  0

and this at least does not generate the linker warning about overflow.
Can I turn my initial statement:

	.short	PLUS-0x610000

into a PC16 relocation somehow?

Some platforms support the modificator lo16(addr). This is the ideal
solution for my problem; unfortunately, i386 does not support it.

> For portability to other machines, you might consider writing
> your own trivial assembler and linker for the forth.  You
> can then include the linked forth program into the native 
> binary via .incbin or the like.
That's what I'm trying to avoid by using binutils as the swiss army
knife :)

-- 
Andrew

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