Re: [hatari-devel] Handling of _drvbits

[Thomas Huth <th.huth@xxxxxxxxx>]

Am Sat, 12 Jul 2025 15:52:53 +0200
schrieb Uwe Seimet <Uwe.Seimet@xxxxxxxxx>:

> > FWIW, that's what I recall from former times: TOS clears the variable at
> > one point during startup, that's why we have to set it again via
> > OpCode_SysInit().
> > 
> > If you want to use GEMDOS harddisk partitions together with a hard disk
> > driver, you're better off using letters from the end of the alphabet for
> > your GEMDOS partitions.  
> 
> In my case there is no need for this work-around, because with Hatari I
> launch HDDRIVER from the AUTO folder of drive C:, not from an image. When
> configured accordingly, HDDRIVER does not overwrite existing GEMDOS drive
> IDs, but assigns the image partitions starting with the first unused drive
> in _drvbits. So GEMDOS drives are always first, regardless of the partitions
> on any images present.
> 
> What I was wondering is why this does not work when booting HDDRIVER from
> an image. My guess is that at the time TOS loads the hard disk driver
> _drvbits is still empty, so that HDDRIVER assigns partitions starting with C:.
> Hatari sets its GEMDOS drive bits later and overwrites _drvbits
> unconditionally.
> I just wanted to know if somebody can confirm this behavior of TOS/Hatari.

Yes, that's what I recall from former times.

 Thomas