Re: [cc65-devel] Binary loads of overlays on various targets

[Oliver S. <ol...@we...>]

Hi Groepaz,

First of all thanks for the quick answer :-)

>> 1. read() with "default DOS" (let's define this as performance of 1.0)
>> 2. cbm_load() with "default DOS".

> this doesnt make a huge difference. irrelevant in practise unless

That's what I sort of expected.

>> 3. read() with fast-loader.
>> 4. cbm_load() with fast-loader.

> LOAD goes over a vector, which most fastloaders hook into. so for example with
> an action replay, 4) would be accelerated by the fastloader - but 3) would
> still be as slow as without one. that is pretty much the one reason for why
> you should always use LOAD if possible. (same thing applies to SAVE too)

Okay, so if the overlaydemo and multidemo programs are supposed to be
more than a proof-of-concept then they should use cbm_load() on the
C64 - right? Especially as it's not only about some sample programs
but about the overlay linker configs which are part of the "official"
linker config set.

So
https://github.com/oliverschmidt/cc65/blob/master/cfg/c64-overlay.cfg
https://github.com/oliverschmidt/cc65/blob/master/cfg/c128-overlay.cfg
should define 2-byte headers for the overlay files. And as the overlay
load address is well known at link time the headers should contain the
correct load address so that cbm_load() can be called with NULL as
third parameter - correct?

Regards,
Oliver