Re: [avr-gcc-list] forcing address

[Marlin Unruh]

Hi J"org,

Ten years ago I wrote some assembly language for the Motorola
MC68HC11 and we are still selling that product. But anyway, it must
have been an absolute assembler.  The code was passed thru a
linker. Using the org "origin" directive the code was placed where
you wanted it. I thought maybe the compiler had way to pass info to
the linker, and the linker would pack the code and place it at a given
location. But, I understand what you are saying.  It is as it is.

Where could I get a list of the directives for the GCC assembler?

Thank you for you reply.
Marlin

At 02:08 PM 8/19/2002 +0200, you wrote:
> Marlin Unruh <address@hidden> wrote:
>
> > I am writing an assembly file to include some time, and sequence
> > sensitive code. I have a lookup table that I defined in the .s
> > file. I cannot get the compiler to place the lookup table at a given
> > location.
>
> Sure.  This is a linker issue, and usually, in an environment that
> uses compilation that results in relocatable object files, you cannot
> arbitrarily place your code at predetermined locations.  This is only
> possible when using absolute assembly.  (Even in the old days of the
> Z80, it was common to use relocatable assembly, and have the linker
> put all the pieces into place.)
>
> Using linker directives, you can tell the linker at which address to
> place the beginning of your program.
>
> How else would you expect the whole thing to work?  Say, you want some
> particular piece of code at address 0x100, but the startup code starts
> at 0x0.  How should the compiler be told that there are some XXX bytes
> free between the startup code and your code at 0x100 (that could be
> filled by the compiler)?
>
> --
> J"org Wunsch                                           Unix support engineer
> address@hidden        http://www.interface-systems.de/~j/
> avr-gcc-list at http://avr1.org

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