On Thu, May 30, 2013 at 09:30:33AM +0200, Gerd Hoffmann wrote: > On 05/30/13 03:34, Kevin O'Connor wrote: > > On Wed, May 29, 2013 at 04:25:59PM +0200, Gerd Hoffmann wrote: > >> Allow selecting DEBUG_IO for non-qemu configurations, > >> which is useful when running coreboot+seabios on qemu. > > > > Unfortunately, if one does run seabios on real hardware and has > > DEBUG_IO enabled, it will write to IO port 0x402 before confirming > > that it is actually running on QEMU. This could cause mysterious > > failures on real hardware if something is listening to that port. > > It's why I left the option dependent on QEMU instead of QEMU_HARDWARE. > > Ideally the code would verify it is on QEMU before using the IO port, > > while still providing the very early debugging when it is known to be > > safe. > > The debgconsole port returns 0xe9 on reads, so we could use that for > probing and do something like the attached patch. Which doesn't build > for some reason. Is the F segment read-only in 16bit mode? Should I > use something else instead? Or #ifdef the SET_GLOBAL for 32bit mode, > which should work fine given that POST runs in 32bit mode?
Same problem - one can't reliably do an inb(0xe9) on real hardware without risking mysterious failures. -Kevin _______________________________________________ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
