[SeaBIOS] Bug#678042: seabios - Please enable Xen support

[Kevin O'Connor]

On Wed, Jun 20, 2012 at 10:25:13AM +0100, Ian Campbell wrote:
> On Wed, 2012-06-20 at 10:22 +0100, Ian Campbell wrote:
> > Subject: [PATCH] enable Xen support by default.
> 
> In this context I thought it would also be useful to make
> CONFIG_DEBUG_IO_PORT dynamic. However with the below I get lots of build
> errors about xen_cpuid_base not being defined. I got similar errors
> without the VAR16VISIBLE and GET_GLOBAL hunks. I suspect this is due to
> the variable being used in both 32 and 16 bit mode and my not knowing
> what I'm doing in that regard ;-)

xen_cpuid_base is defined in xen.c which is only compiled in 32bit
mode, so you can't declare a variable as VAR16VISIBLE there.

I wonder if it is simpler to define a "u16 DebugOutputPort
VAR16VISIBLE = CONFIG_DEBUG_IO_PORT" in output.c and then override it
early in the xen boot sequence though.

-Kevin