> Date: Sun, 22 Aug 2021 23:18:41 -0400
> From: George Koehler <[email protected]>
>
> This sloppy diff enables astfb on my Talos. It works around the
> firmware's wrong sc_fbaddr by mapping PCI BAR 0x10 and using it as a
> framebuffer. Mark, you might make a better diff?
That doesn't work since the framebuffer may start at an offset within
that BAR. At least it does on my machine.
> "pcidump -v" didn't show my ast vga device until I made the missing
> /dev/pci5 node. Then it showed some BARs. I tried BAR 0x10 because
> its size seemed big enough for a framebuffer. I got the idea from
> some code in /usr/xenocara/driver/xf86-video-ast that seemed to use
> a PCI region as a framebuffer.
Hmm, we probably should have MAKEDEV create more /dev/pciN nodes.
> When I started xenodm, the colors were wrong. I added some code to
> xf86-video-wsfb that fixed some colors, but caused emacs to crash
> in a weird way. --George
Yeah, the framebuffer is little-endian. Ideally we'd have an wscons
ioctl that returns the actual pixel format, but you can use the
WSDISPLAY_TYPE_ASTFB and check you're running on a big-endian system
instead.
However, it seems that some parts of X are just plain broken with the
pixel format that you end up with.
> Index: arch/powerpc64/dev/astfb.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/powerpc64/dev/astfb.c,v
> retrieving revision 1.3
> diff -u -p -r1.3 astfb.c
> --- arch/powerpc64/dev/astfb.c 30 Oct 2020 13:36:45 -0000 1.3
> +++ arch/powerpc64/dev/astfb.c 23 Aug 2021 02:49:48 -0000
> @@ -118,8 +118,17 @@ astfb_attach(struct device *parent, stru
> sc->sc_iot = pa->pa_memt;
> if (bus_space_map(sc->sc_iot, sc->sc_fbaddr, sc->sc_fbsize,
> BUS_SPACE_MAP_LINEAR, &sc->sc_ioh)) {
> - printf(": can't map framebuffer\n");
> - return;
> + bus_size_t size;
> + pcireg_t maptype;
> +
> + maptype = pci_mapreg_type(pa->pa_pc, pa->pa_tag, ASTFB_PCI_FB);
> + if (pci_mapreg_map(pa, ASTFB_PCI_FB, maptype,
> + BUS_SPACE_MAP_LINEAR, &sc->sc_iot, &sc->sc_ioh,
> + &sc->sc_fbaddr, &size, 0) != 0) {
> + printf(": can't map framebuffer\n");
> + return;
> + }
> + printf(": BAR size 0x%zx", (size_t)size);
> }
>
> printf("\n");
>
