On 01/02/2010 09:53 AM, Kevin O'Connor wrote: > On Fri, Jan 01, 2010 at 07:02:59PM -0800, H. Peter Anvin wrote: >> On 12/30/2009 08:49 AM, Kevin O'Connor wrote: >>> SeaBIOS writes debugging info to port 0x0402. Unfortunately, qemu has >>> to be recompiled in order to display this info. Will your patch >>> enable one to get at the 0x0402 data without recompiling? >> >> Incidentally, it's somewhat unusual choice of ports... port 0x80 is the >> normal port for BIOSes to display debugging information on. > > Port 0x0402 is a carry over from Bochs bios. > > Port 0x80 isn't generally used to emit a stream of ascii data, and it > can be used by other programs besides the bios. I'd guess that's why > Bochs chose a different port. > > -Kevin
Makes sense. Either way, it works with my patch looking something like: -chardev stdio,id=seabios \ -device isa-debugcon,iobase=0x402,chardev=seabios ... should do the job. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.