Path: utzoo!attcan!uunet!mcsun!hp4nl!phigate!philica!adrie
From: adrie@philica.ica.philips.nl (Adrie Koolen)
Newsgroups: comp.os.minix
Subject: Re: Specifying floppy types
Message-ID: <692@philica.ica.philips.nl>
Date: 22 Oct 90 15:51:10 GMT
References: <1990Oct13.120111.21252@math.lsa.umich.edu> <1370@carol.fwi.uva.nl> <1990Oct14.025522.4259@math.lsa.umich.edu> <2452@runxtsa.runx.oz.au>
Reply-To: adrie@beitel.ica.philips.nl (Adrie Koolen)
Organization: Philips TDS, Innovation Centre Aachen
Lines: 18

In article <2452@runxtsa.runx.oz.au> brucee@runxtsa.runx.oz.au (Bruce Evans) writes:
>There was a good reason for avoiding ioctls in the 1.5 PC formatting interface.
>The ioctl interface is weak (there is no way to pass more values than fit in
>a message) and I had already changed too many things. I think the ST patch3
>now passes a pointer to a user buffer like other *nix's.

The Minix-Sparc floppy format method uses an ioctl() to format a track.
A pointer to a structure, containing formatting and disk parameters, is
passed. This structure contains the cylinder and head number, the density
and a pointer to an array, which contains sector numbering info. The
latter array isn't that nice, because it is controller specific, but the
usage of an ioctl() allows me to use SUSPEND replies so that the FS isn't
stopped while formatting a track. I don't see why the ioctl() interface
is weak. At least, there's no problem in tranferring an arbitrary amount
of data to the kernel. The driver should be a character type, though.

Adrie Koolen (adrie@ica.philips.nl)
Philips Innovation Centre Aachen