Re: [hatari-devel] IDE IO register range access commit

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 24/09/2020 à 21:02, Eero Tamminen a écrit :
> Hi,
>
> Nicolas, I think IDE would work correctly if
> memory.c would just check for:
> Config_IsMachineFalcon() || ConfigureParams.Ide[0].bUseDevice
>
> And all ide.c changes were reverted, as they break the other 
> expectations that code has.
>
> (Or you could add separate check function to ide.c
> instead of mangling the existing internal one.)

Hi

I'm not sure it would work if I do in memory.c :
Config_IsMachineFalcon() || ConfigureParams.Ide[0].bUseDevice

instead of calling Ide_MmioIsAvailable() which does the same, because 
then this code in ide.c looks wrong to me :

        if (addr >= 0xf00040 || !Ide_MmioIsAvailable())
		{
			M68000_BusError();
		}

As thomas noted in another mail, this means that if you're in falcon 
mode and access 0xf00005 for example and there's no disk in ide[0], then 
you trigger a bus error ; this is wrong, original HW doesn't do that. So 
IMO Ide_MmioIsAvailable() should also check machine==falcon.

I think that what is missing and I tried to fix is that there should be 
an init of IDE for falcon or when IDE is forced (malloc memory for 
ide[0] and ide[1], even if this memory is empty for now) ; this init 
should be done once for all on each boot or when machine type is changed 
if it implies that IDE registers get enabled/disabled.

And then there should be another function that only deals with 
"inserting" and ide image into ide[0] or ide[1], which is more or less 
what ide_init2() is doing if I understand it correctly.

Just reverting to previous ide.c code will leave some pending issues 
with falcon that will trigger a bug sooner or later ; better try to fix 
it now.

Nicolas