Hi there,

I'm hoping Oliver will see this message :) I've worked a bit on a
linker configuration allowing my program to live from $803 to $3FFF and
use the HGR2 page. The program worked well using HGR1, but its code
can't live entirely between $803 and $1FFF, so it's much bigger than
needed on disk, having 8kB of zeroes on HGR1.

I've managed to make this linker config:
https://github.com/colinleroy/a2tools/blob/master/config/apple2enh-hgr2.cfg

It seems to work good and safe. I checked that the linker errors out if
I put too much code and it crosses the $4000 boundary; I've also
checked that malloc() does the right thing, not touching HGR
page 2 (it starts allocating at $6000 + BSS size + stack size).

I'd love a second opinion though :)

Thanks!
--
Colin
https://www.colino.net/

Hi Colin,

>I'm hoping Oliver will see this message :)

Here I am...

>I've managed to make this linker config:
>https://github.com/colinleroy/a2tools/blob/master/config/apple2enh-hgr2.cfg

The config looks absolutely sane to me.

>It seems to work good and safe. I checked that the linker errors out if
>I put too much code and it crosses the $4000 boundary; I've also
>checked that malloc() does the right thing, not touching HGR
>page 2 (it starts allocating at $6000 + BSS size + stack size).

The heap starts at $6000 + BSS size. The stack starts at HIMEM and
grows downwards towards the heap.

>I'd love a second opinion though :)

I don't see a problem. However, I'm wondering why you don't go the
from my perspective simpler way to load your program at $4000 and use
$803 to $2000 as additional heap.

That alternative doesn't require an own custom linker config. Just use
the '--start-addr $4000' cmdline parameter and add the heap as
described in https://cc65.github.io/doc/apple2.html#ss5.2

The HGR sample programs coming with cc65 doit this very way:
https://github.com/cc65/cc65/blob/master/samples/Makefile#L108-L112

Regards,
Oliver

Hi,

>The heap starts at $6000 + BSS size. The stack starts at HIMEM and
>grows downwards towards the heap.

Uh, right :) Had a little brainfart there.

>>I'd love a second opinion though :)
>
>
>I don't see a problem. However, I'm wondering why you don't go the
>from my perspective simpler way to load your program at $4000 and use
>$803 to $2000 as additional heap.

That's mostly because I didn't think of it! Thanks for the input.

--
Colin
https://www.colino.net/

Hi,

>>I don't see a problem. However, I'm wondering why you don't go the
>>from my perspective simpler way to load your program at $4000 and use
>>$803 to $2000 as additional heap.
>
>That's mostly because I didn't think of it! Thanks for the input.

Not only is it simpler, it's also cooler because I can still use
VIDEOMODE_80COL and/or MIXSET.

Thanks!
--
Colin
https://www.colino.net/

Hi Colin,

> [...]
> Thanks!

You're welcome! Thanks for the kind feedback :-)

Regards,
Oliver