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
