[SeaBIOS] [PATCH] fix calculation of PkgLength

[Hu Tao]

On Sun, Jul 14, 2013 at 09:12:42PM -0400, Kevin O'Connor wrote:
> On Fri, Jul 12, 2013 at 10:08:01AM +0800, Hu Tao wrote:
> > On Sun, Jul 07, 2013 at 11:42:40PM -0400, Kevin O'Connor wrote:
> > > On Wed, Jul 03, 2013 at 05:59:07PM +0800, Hu Tao wrote:
> > > > Currently the calculation of PkgLength isn't acpi-compliant. This
> > > > patch fixes it to be acpi-compliant.
> > > 
> > > What isn't acpi compliant with the current calculation?
> > 
> > Currently, the length of PkgLength itself is hard-coded(third parameter
> > of encodeLen). If the length of PkgLength must have strictly the
> > relationship with package length as follow as in ACPI specification:
> > 
> >  package length      PkgLength
> >  0-63                1 byte
> >  64-4096(2^12)       2 bytes
> >  4097-1048576(2^20)  3 bytes
> >  >1048576            4 bytes
> > 
> > then current calculation is not acpi-compliant. But if not, say,
> > a 4-byte PkgLength can legally encode a 10-byte package, then current
> > calculation is acpi-compliant.
> 
> My read of the spec was that one can always use a larger length
> encoding than needed.  I haven't seen any issues with it in my tests.
> Can you confirm that the length encoding is causing problems for you?

You're right. I confirmed that the cause of Windows BSOD is wrong hard-coded
package length, not bytes of PkgLength.