Re: [Qemu-devel] [PATCH] Floppy: Remove Sense Interrupt Hack

[Blue Swirl]

On 12/19/08, Justin Chevrier <address@hidden> wrote:
>
>
>
>  --- On Fri, 12/19/08, Blue Swirl <address@hidden> wrote:
>
>  > From: Blue Swirl <address@hidden>
>  > Subject: Re: [Qemu-devel] [PATCH] Floppy: Remove Sense Interrupt Hack
>  > To: address@hidden, address@hidden
>  > Date: Friday, December 19, 2008, 2:43 PM
>
> > On 12/18/08, Justin Chevrier <address@hidden>
>  > wrote:
>  > > Hey guys,
>  > >
>  > >  I'm tracking down the next issue(s) with the
>  > Openserver installation. The current issue is that during
>  > installation when the installer tries to link the BLTD (eg.
>  > SCSI drivers) drivers into the kernel it is unable to access
>  > the floppy drive. After reviewing the debug logs it turns
>  > out that the installer dosen't like the value being
>  > returned by Sense Interrupt. The cause of this is a hack in
>  > the Sense Interrupt code that always returns an OR'd
>  > value based on FD_SR0_SEEK instead of the actual Status0
>  > regsiter. The hack identifies that the floppy code is broken
>  > with regard to Status0 and Read/Writes. Outside of setting
>  > particular values in case of CRC errors/etc I can't
>  > identify from datasheets what we should be doing. I've
>  > tracked down what I believe is the original mailing list
>  > post regarding this hack and it seems to be related to
>  > Windows 2000 and higher OS's recognizing the floppy
>  > drive. I applied the patch below and verified that
>  > >   detection/read/writes/formatting still work in
>  > Windows XP SP2.
>  > >
>  > >  Original post:
>  > >
>  > http://lists.gnu.org/archive/html/qemu-devel/2004-10/msg00076.html
>  > >
>  > >  SVN change:
>  > >
>  > http://svn.savannah.gnu.org/viewvc?view=rev&root=qemu&revision=1118
>  > >
>  > >  Having said the above does anyone know what the
>  > comment in the hack is referencing? Is it still needed? If
>  > so what needs to be done to eliminate it?
>  > >
>  > >  If it's no longer needed I propose the patch
>  > below.
>  > >
>  > >  Justin
>  > >
>  > >  Changelog:
>  > >
>  > >  Remove Sense Interrupt hack
>  > >
>  > >  Signed-off-by: Justin Chevrier
>  > <address@hidden>
>  >
>  > It may be a hack, but if we remove it, Sparc64 refuses to
>  > boot and
>  > prints endlessly:
>  > SENSEI c0 00
>  > SENSEI c0 00
>  > SENSEI c0 00
>  > SENSEI c0 00
>
>
> Okay, thanks for the feedback!
>
>  I'll start looking into what SPARC64 expects here.

The message is printed here:
http://tracker.coreboot.org/trac/openbios/browser/openbios-devel/drivers/floppy.c#L359