On Thu, Dec 06, 2012 at 06:10:46PM +0100, Alexander Graf wrote:
If I could figure out how to write a reliable _STA method for the SMC, that would detect whether or not it was supplied as "-device applesmc" on the qemu command line, I think we might be on to something...
You should be able to poke fw_cfg in the _STA method. The machine file could search its bus on init (or on machine create notify) and populate a fw_cfg variable to indicate whether it found an applesmc.
So the fw_cfg looks like this in 'info qtree':
dev: fw_cfg, id "" ctl_iobase = 0x510 data_iobase = 0x511 irq 0 mmio ffffffffffffffff/0000000000000002 mmio ffffffffffffffff/0000000000000001
I'm confused by the mmio values (start at the very top of memory, go for one or two bytes from there ?)
I also found this patch by Gerd, which doesn't seem to have made it upstream (yet):
http://www.mail-archive.com/qemu-devel@nongnu.org/msg110131.html
That patch suggests that I could just write stuff to 0x510 and read from 0x511, and if I get it "right" the values I read will end up making sense :)
Can anyone can point me to an example of how to interact with fw_cfg ?
Thanks, --Gabriel