[SeaBIOS] [PATCH] support T13 EDD3.0 spec

[Gleb Natapov]

On Sat, Jan 08, 2011 at 01:48:00PM +0100, Sebastian Herbszt wrote:
> Kevin O'Connor wrote:
> >On Thu, Jan 06, 2011 at 04:24:13PM +0200, Gleb Natapov wrote:
> >>On Thu, Jan 06, 2011 at 09:00:00AM -0500, Kevin O'Connor wrote:
> >>> On Thu, Jan 06, 2011 at 03:53:57PM +0200, Gleb Natapov wrote:
> >>> > On Thu, Jan 06, 2011 at 08:41:11AM -0500, Kevin O'Connor wrote:
> >>> > > On Thu, Jan 06, 2011 at 07:09:27AM +0200, Gleb Natapov wrote:
> >>> > > > On Wed, Jan 05, 2011 at 09:32:33PM -0500, Kevin O'Connor wrote:
> >>> > > > > > -        SET_INT13DPT(regs, host_bus[3], 0);
> >>> > > > > > +        SET_INT13DPT(regs, host_bus[3], ' ');
> >>> > > > > > > > > > What if we're not in t13 mode?  Should this
> >>be:
> >>> > > > >   u8 fillchar = t13 ? ' ' : 0;
> >>> > > > >   SET_INT13DPT(regs, host_bus[3], fillchar);
> >>> > > > > > > > > Phoenix does not specify padding. Are you sure
> >>phoenix has to have zero
> >>> > > > padding?
> >>> > > > > > I think RBIL documented 0s.  It may not be
> >>important.
> >>> > > > > What is RBIL?
> >>> > Sorry - Ralph Brown's interrupt list:
> >>> > http://www.cs.cmu.edu/~ralf/files.html
> >>> Ah, I have it, just didn't know it is called RBIL :).
> >>
> >>Do you want me to resend with fillchar = t13 ? ' ' : 0; or space should
> >>be good enough?
> >
> >I just tested winxp, and it doesn't seem to call 1348 with a size
> >bigger than 26 bytes.  So, thinking about it further, I'm not sure it
> >matters - the spec isn't clear and I don't know of anything that would
> >care.  (To be clear, I think we should support the 66 byte buffer
> >size, however I'm not sure the padding matters.)
> >
> >Sebastian - do you know of anything that calls 1348 with a buffer size
> >that could observe the difference?
> 
> I think syslinux and FreeDOS call 1348 - will check their buffers later.
> 
> I have tested 1348 on VMware Player 3.0.0 build-203739. It runs
> PhoenixBIOS 4.0 Release 6.0, VMware BIOS build 314. Results:
> Input Buffer length -> Output Buffer length
> 1a -> 1a
> 1e -> 1e
> 42 -> 1e (looks like it doesn't support 42!)
> 4a -> 4a (wrong output buffer length, should be 1e; uses space padding)
> 
> Will do more tests later.
> 
RBIL mention that: 
 Dell machines using PhoenixBIOS 4.0 Release 6.0 fail to correctly
 handle this function if the flag word at DS:[SI+2] is not 0000h on
 entry
Make sure to have it set to zero in you testing. May be VMware's
build has the same problem.
 
--
			Gleb.