Sebastian Herbszt wrote: > Jan Kiszka wrote: >> Sebastian Herbszt wrote: >>> Simon Bienlein wrote: >>>> Is a support for BIOS worked on right now? >>> >>> The vgabios (vgabios.c) has a "FIXME should beep". Volker, do you plan >>> to fix this? >>> >>> Which frequency should be used for the beep? Which delay? >> >> I would try 1 KHz and some hundred milliseconds. > > I just looked at some vga bios and it uses about 896,45 Hz. > >>> Getting a delay using "inb(0x61) & 0x10" is still a no go on qemu, >>> right? >> >> Looks like (should be far too inaccurate for longer delays). What about >> 0x40:0x6c, the BIOS' daily timer counter? > > The bios i looked at used the refresh request port 0x61. This is > supported by bochs and > there is also a patch for qemu to replace the dummy [1]. The rombios > uses this to provide > INT 15h AH=86h functionality; this is likely broken with the dummy code > in qemu. I see no problem with improving qemu's emulation accuracy this way a bit. But I wouldn't built new delay implementations on top of it, specifically if the code is in fact aware of running over a hypervisor. Such micro-timings are far too inaccurate for longer delays in an environment where you cannot be sure of running all the time during that period. > > Anyway, using "timer ticks since midnight" should be possible (INT 08h > handler is set up > before vga bios is called). > > [1] http://article.gmane.org/gmane.comp.emulators.bochs.devel/7594 > > - Sebastian > Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
