On Thu, Feb 13, 2025 at 01:47:16PM -0500, Greg Troxel wrote: > Emile `iMil' Heitor <i...@home.imil.net> writes: > > > Understood. So as this seems to only impact qemu/microvm should we > > consider an if (vm) test? > > I have a bias against "if (vm)" unless that is truly the semantics. > Here it feels like bad/odd RTC behavior, and real hardware could do > whatever, so handling the bad behavior without regard to cause seems > best.
I'm not sure what you call "bad/odd RTC behavior". Here we're just reading a byte of the sram, its value can be anything from 0 to 0xff. This value is supposed to be written by the BIOS. I think, from our current definition of NVRAM_DIAG_BITS, that some bits are not supposed to be set to 1, but I'm not sure if our NVRAM_DIAG_BITS is up to date. Are you suggecting that we should find another way to detect if the mc146818 is present ? AFAIK it's the other way round: unless we know it's not present (because e.g. we're in an environnement known to not have it like some hypervisors or emulators) we have to assume it's present (because it's a mandatory part of the hardware). -- Manuel Bouyer <bou...@antioche.eu.org> NetBSD: 26 ans d'experience feront toujours la difference --