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Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download)

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"Michael J. Mahon" <mjmahon@aol.com> wrote:
>In Merlin, you can semi-automate this kind of code splitting by 
>occasionally calling a macro that checks proximity to a reserved region

Aztec C also refer to the hole as a region. So going forward with my 
documentation of porting Aztec C65 to cc65 which will become a book when I 
am finished, I will use the phraseology of a "reserved region" and "program 
hole" and attempt to refrain from "BuckSpeak" which only works for MS-DOS 
programmers. This matter of program segments in cc65 is a little too 
complicated already to talk about casually without confusing the reader.

That should do it.

>This works reasonably well if used just before a procedure. Since the macro 
>can't know how long the procedure will be, it can default to a reasonable 
>size, or an argument can be passed with the programmer's estimate of the 
>size.

LN65 has additional switches when reserved segment start addresses for code, 
data, and initialized data are used explicitly.

>Another version of this, suitable for use inside a procedure, would check 
>for being within 3 bytes of the region, and generate a JMP around it, but 
>that messes up any relative branches across the region.

I don't think any scheme is much different in theory, but the LN65 Hole 
switch seems to be a little more friendly because it is much less work for 
the programmer.

When I first got the Aztec C65 compiler, this took no explanation, unlike 
this cc65 linker config. So in the longer term, perhaps in the final chapter 
of the book, I'll change the cc65 linker and add reserved regions to its 
command line.

Bill 

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Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) "Bill Buckels" <bbuckels@mts.net> - 2014-05-23 21:45 -0500
  Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) Michael J. Mahon <mjmahon@aol.com> - 2014-05-23 22:20 -0500
    Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) "Bill Buckels" <bbuckels@mts.net> - 2014-05-23 23:03 -0500
      Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) David Schmidt <schmidtd@my-deja.com> - 2014-05-24 00:18 -0400
        Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) "Bill Buckels" <bbuckels@mts.net> - 2014-05-24 08:49 -0500
      Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) "Bill Buckels" <bbuckels@mts.net> - 2014-05-24 10:58 -0500
      Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) Michael J. Mahon <mjmahon@aol.com> - 2014-05-24 11:04 -0500
        Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) "Bill Buckels" <bbuckels@mts.net> - 2014-05-24 14:28 -0500
          Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) ol.sc@web.de (Oliver Schmidt) - 2014-05-30 21:20 +0000
            Re: Linker Configs and Screen Holes (Was: Re: Double Hi-Res Demo in cc65 available for Download) "Bill Buckels" <bbuckels@mts.net> - 2014-05-30 18:35 -0500

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