[hatari-devel] IDE in ST/STE mode?

Thomas Huth huth at users.berlios.de
Fri Apr 3 17:46:13 CEST 2009


On Wed, 1 Apr 2009 23:31:56 +0300
Eero Tamminen <eerot at users.berlios.de> wrote:

> > For the ACSI code, there's some magic in hdc.c which parses the
> > partition table on the HD image (see HDC_GetInfo), so the GEMDOS
> > drive letter can be mapped after the ACSI partitions.
> 
> I took a look at that, but it's lacking a lot of things:
> - Doesn't support extended (XGM) partitions
> - Doesn't support ICD partition table format
>   (8 additional partition entries on root sector)
> - Doesn't support MSDOS partition table
>   (supported by several HD drivers)
> 
> > But this code  does not exist for the IDE layer yet,
> 
> I think the partition counting code could be shared between the two
> (mbr.c?).

Well, maybe, but then the code would also have to take care of
endianess issues (IDE images are byte-swapped).

> The hard thing is knowing what's supported on the TOS side though:
> - EmuTOS supporting only DOS MBR, or (also)
> - HD driver supporting only old AHDI MBR / GEM partitions, or
> - HD driver supporting also new AHDI MBR (BGM & XGM partitions), or
> - HD driver supporting (also) ICD partition table format
> - No EmuTOS or HD driver
> 
> Because if that's guessed wrong, either GEMDOS emu goes over a
> partition, or there's a partition "gap".
> 
> How that could be solved?
> 
> Maybe by getting rid of the ACSI & IDE partition counting code
> completely and just requiring user to specify partition offset for
> GEMDOS drives when using them with ACSI or IDE emulation?

Yes, either we could use an offset for the first GEMDOS drive, or we
make it fully configurable for each drive (like Kenneth does it already
by enumerating the drives by the folder names).

> > so there is a conflict when using IDE and GEMDOS at the same time.
> 
> But ACSI & IDE should work together?

Yes, I think so (since this is the job of the Atari side hard disk
driver).

 Thomas



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