Re: [hatari-devel] Small patch to add some partition IDs for auto-detection of byteswapped images

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 12/5/18 11:53 AM, Thorsten Otto wrote:
> attached is a small patch that adds some more partition types to the detection
> ('F32', 'MIX' and 'UNX'). There are also 2 more types which are mentioned in
> the XHDI specification  ('QWA' and 'MAC'), but i have never seen them,
> and i think filesystem drivers for them don't exist, but the above
> ones are actually in use.

These are already checked by Hatari:
	GEM     GEMDOS partition < 16MB
	BGM     GEMDOS partition > 16MB
	XGM     Extended partition (containing others)
	RAW     No file system
	LNX     Linux Ext2 partition,  not handled by TOS
	SWP     Swap partition,  not handled by TOS

You suggested adding these:
	F32     TOS compatible FAT32 partition
	MIX     Minix partition,  not handled by TOS
	UNX     ASV (Atari System V) partition,  not handled by TOS

(Which seems fine)

And leaving these out:
	MAC     MAC HFS partition,  not handled by TOS
	QWA     QDOS partition,  not handled by TOS

Linux m68k supported HFS on Atari according to:
https://www.debian.org/releases/slink/m68k/ch-hardware-req.en.html

But Linux Atari partition table code doesn't list "MAC" type:
https://elixir.bootlin.com/linux/v4.0/source/block/partitions/atari.c

-> I guess HFS was used with other than Atari partition types
   on Linux?

Would one need HFS partitions on Atari partition table
when using Aladin or Spectre Mac emulator:
	https://en.wikipedia.org/wiki/Spectre_GCR
?


QDOS / QWA seems to refer to Sinclair QL QDOS:
  https://en.wikipedia.org/wiki/Sinclair_QDOS

Which was also ported to Amiga:
  http://aminet.net/search?query=qdos

(Took a lot of time to dig out as I found also Atari 8-bit QDOS
& 8086 QDOS, and I didn't find any documentation on hard disk
partition formats on any of these.)


There's apparently a SW/HW emulator QL for Atari ST:
	https://en.wikipedia.org/wiki/SMSQ/E
	http://st-news.com/issues/st-news-volume-4-issue-2/reviews/ql-emulator/

So maybe QWA partitions come from it?  At least Johan Klockars' QLemu
(only other QL emu I found) doesn't do anything with hard disks.



Btw. Partition type detection is used (only) for checking whether
harddisk should be byte-swapped.  However, it's done only for
the first Atari partition table partition.

It's not done for DOS MBR (supported by EmuTOS and e.g. Uwe's
HD driver).  Could HDs with MBR be also byte-swapped?


	- Eero

---
According to AHDI documentation, "XGM" (extended) partition cannot
be the first one, because HD cannot booted from it.

However, it's also possible to boot from another hard disk (image)
or from a floppy with a HD driver, so it's possible to use a HD that
doesn't TOS compatible first partition.

-> I guess other partition types need to be checked for byte-swap,
like they already are, and what you proposed to extend.


Partition table list is used for two purposes:

* Debug output to console
* GEMDOS HD partition "skip" option, which is relevant only with TOS,
  as GEMDOS HD works only with that