Re: [SeaBIOS] [RFC PATCH] Add support for Intel Quark UART.

[Kevin O'Connor]

On Mon, May 19, 2014 at 07:49:47PM +0100, David Woodhouse wrote:
> On Mon, 2014-05-19 at 13:42 -0400, Kevin O'Connor wrote:
> > I don't see any reference to "int 15h, ax=0xd042" as a standard.  So,
> > maybe the author of the above text also wrote their own EFI module
> > which used that magic value?
>
> Well, the INT 15h call would still be on the BIOS side; that doesn't
> sound like an EFI thing at all. Perhaps that's a special-case hack to
> make their platform *trigger* the SMM entry, which then gets handled by
> the EFI code?

FYI, I just stumbled upon this definition in the std/LegacyBios.h efi
header file:

///
/// SMM_FUNCTION Function constants.
///@{
#define INT15_D042        0x0000
[...]

-Kevin