[SeaBIOS] [PATCH] fix two issues with virtio-blk

[Kevin O'Connor]

On Thu, May 13, 2010 at 02:00:24PM +0300, Gleb Natapov wrote:
> On Wed, May 12, 2010 at 07:25:55PM -0400, Kevin O'Connor wrote:
> > The blksize needs to be 512, because the BIOS interface that virtio
> > binds to requires 512 byte sectors.  Shouldn't this look something
> > like:
[...]
> Hmm, I guess you are right. Boot indeed fails if I configure logical
> block size bigger then 512 bytes. But shouldn't BIOS emulate 512 byte
> access on top of bigger block size? Future disks will use much large
> logical block sizes.

SeaBIOS only supports 512 byte sectors for floppies/harddrives and
only supports 2048 byte sectors for cdroms.  I suppose one could
implement an emulation layer (similar to the way the "El Torito" spec
can make a cdrom look like a harddrive), but so far nothing has
required that.

I suspect future drives will boot in a legacy mode that uses a 512
byte block interface - exactly because of these types of issues.

-Kevin