On Thu, Nov 04, 2010 at 03:03:10PM +0800, Lin Ming wrote:
I just find that I can't send output to the QEMU BIOS debug port. It's caused by commit d4bded451.
In qemu-kvm/hw/acpi_piix4.c, #define ACPI_DBG_IO_ADDR 0xb044
Don't know why the DBG was changed from 0xb044 to 0x0402. But it still does not work if I changed the port back to 0xb044.
OperationRegion (DBG, SystemIO, 0x0402, 0x01)
OperationRegion (DBG, SystemIO, 0xb044, 0x01)
That was intentional. The new system sends output using the regular bios debug mechanism - you should be able to see that output by adding the following to qemu command line:
-chardev stdio,id=seabios \ -device isa-debugcon,iobase=0x402,chardev=seabios
The above should be simpler then having to recompile qemu with acpi debugging.