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

[Sebastian Herbszt]

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.

Freedos - 30
syslinux - 66
GRUB2 - 66
Linux - 74

Sebastian