[SeaBIOS] seabios: acpi: add _RMV control method for PCI devices

[Marcelo Tosatti]

On Sat, Dec 11, 2010 at 09:39:30AM +0200, Avi Kivity wrote:
> On 12/08/2010 07:08 PM, Marcelo Tosatti wrote:
> >Use _RMV method to indicate whether device can be removed.
> >
> >Data is retrieved from QEMU via I/O port 0xae0c.
> >
> 
> Where did this port come from?  

Its the next available address after "PCI EJ base", used
for QEMU<->ACPI hotplug communication.

> What's the protocol?

ACPI reads the 32-bit field indicating the return value of the _RMV
method (which is used by Windows to decide removability). 1-bit per
slot.

More ports have to be registered if more buses are added.

> Maybe we should do this via fw_cfg.

I don't see a need for it? (yes, it might be possible, but i'm not
familiar enough with AML).