[SeaBIOS] [PATCH] fix calculation of PkgLength

Hu Tao hutao at cn.fujitsu.com
Fri Jul 12 04:08:01 CEST 2013

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.

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