[SeaBIOS] [PATCH] acpi: hide 64-bit PCI hole for Windows XP

[Kevin O'Connor]

On Fri, Aug 09, 2013 at 11:45:59AM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > Converting src/smm.c to use a runtime value isn't hard - just change
> > the assembler from: "mov $" __stringify(PORT_ACPI_PM_BASE) " + 0x04,
> > %dx\n" to: "mov 4(my_acpi_base), %dx\n" and make sure to define the
> > global variable my_acpi_base as VARFSEG.
> 
> The apm fix brought a ctl register variable we can use directly, so I
> tried the attached patch, then got this:
> 
>   Linking out/rom.o
> out/code32flat.o: In function `smm_relocation_end':
> (.text.asm./home/kraxel/projects/seabios/src/smm.c.72+0x37): relocation
> truncated to fit: R_386_16 against symbol `acpi_pm1a_cnt' defined in
> .data.varfseg./home/kraxel/projects/seabios/src/acpi.c.21 section in
> out/code32flat.o
> out/code32flat.o: In function `smm_relocation_end':
> (.text.asm./home/kraxel/projects/seabios/src/smm.c.72+0x46): relocation
> truncated to fit: R_386_16 against symbol `acpi_pm1a_cnt' defined in
> .data.varfseg./home/kraxel/projects/seabios/src/acpi.c.21 section in
> out/code32flat.o
> make: *** [out/rom.o] Error 1

Use "addr32 movw (acpi_pm1a_cnt), %dx" instead of "mov
(acpi_pm1a_cnt), %dx".

That said, having the smi handler read from the f-segment probably
isn't the best thing to do (though it should work).  Better would be
to make a variable between smm_code_start/end and copy the value in as
part of the smm init, though admittedly that is a bit more
complicated.

-Kevin