On 03/12/14 16:47, Gerd Hoffmann wrote: > > On Mi, 2014-03-12 at 14:55 +0100, Laszlo Ersek wrote: >> On 03/12/14 13:55, Gerd Hoffmann wrote: >>> Hi, >>> >>> This patch series adds new display devices. >>> >>> Number one is secondary-vga. That is identical to VGA (aka -vga >>> std), except that it doesn't occupy all the legacy vga stuff >>> (ioports, memory window @ 0xa0000), so you can have more than one of >>> these in the system. It has one pci memory bar for the framebuffer >>> and one mmio bar for registers. OVMF can drive it. Doesn't use it >>> as console for some reason, but initializes it and the linux kernel >>> will see it as efifb. >> >> My take is, due to the UEFI driver model, QemuVideoDxe is connected >> to this secondary VGA (and so another GOP instance is created). It's >> then probably up to GraphicsConsoleDxe to provide a SimpleTextOutput >> on top. My guess (without looking) is that this too happens, again >> thanks to the UEFI driver model. >> >> What could be amiss is likely something in ConSplitterDxe, which >> accepts input from all consoles, and mirrors output to all of them as >> well. Perhaps it doesn't expect multiple GOPs. > > Must be something else, I see this behavior with secondary-vga being > the only display device. It prints a single line saying something > along the lines "display initialized", so SimpleTextOutput seems to be > active.
OK, maybe I got some further clues; see "OvmfPkg/Library/PlatformBdsLib/BdsPlatform.c". PlatformBdsPolicyBehavior() PlatformBdsConnectConsole() DetectAndPreparePlatformPciDevicePaths() VisitAllPciInstances() VisitAllInstancesOfProtocol() VisitingAPciInstance() DetectAndPreparePlatformPciDevicePath() +---------->IS_PCI_VGA (Pci): | "Found PCI VGA device" | PreparePciVgaDevicePath() | GetGopDevicePath() | BdsLibUpdateConsoleVariable() | The IS_PCI_VGA() macro in "MdePkg/Include/IndustryStandard/Pci22.h" says: > /** > Macro that checks whether device is a VGA-compatible controller. > > @param _p Specified device. > > @retval TRUE Device is a VGA-compatible controller. > @retval FALSE Device is not a VGA-compatible controller. > > **/ > #define IS_PCI_VGA(_p) IS_CLASS3 (_p, PCI_CLASS_DISPLAY, > PCI_CLASS_DISPLAY_VGA, PCI_IF_VGA_VGA) Plus > #define PCI_CLASS_DISPLAY 0x03 > #define PCI_CLASS_DISPLAY_VGA 0x00 > #define PCI_IF_VGA_VGA 0x00 In your patch 2/4 (secondary_class_init()): > + k->class_id = PCI_CLASS_DISPLAY_OTHER; and from qemu's "include/hw/pci/pci_ids.h": > #define PCI_CLASS_DISPLAY_VGA 0x0300 > #define PCI_CLASS_DISPLAY_OTHER 0x0380 I think this is the cause of the mismatch. In vga_class_init(), PCI_CLASS_DISPLAY_VGA is used. Note: build_pci_bus_end() [hw/i386/acpi-build.c] also seems to depend on PCI_CLASS_DISPLAY_VGA. (Of course you could be wanting to avoid exactly that branch, by setting the class to "other".) In edk2, there's another relevant-looking (laxer) macro: > /** > Macro that checks whether device is a display controller. > > @param _p Specified device. > > @retval TRUE Device is a display controller. > @retval FALSE Device is not a display controller. > > **/ > #define IS_PCI_DISPLAY(_p) IS_CLASS1 (_p, PCI_CLASS_DISPLAY) Does the following OVMF patch help? > diff --git a/OvmfPkg/Library/PlatformBdsLib/BdsPlatform.c > b/OvmfPkg/Library/PlatformBdsLib/BdsPlatform.c > index 9f953ac..33d8c5d 100644 > --- a/OvmfPkg/Library/PlatformBdsLib/BdsPlatform.c > +++ b/OvmfPkg/Library/PlatformBdsLib/BdsPlatform.c > @@ -593,7 +593,7 @@ DetectAndPreparePlatformPciDevicePath ( > // > // Here we decide which VGA device to enable in PCI bus > // > - if (IS_PCI_VGA (Pci)) { > + if (IS_PCI_DISPLAY (Pci)) { > // > // Add them to ConOut. > // Thanks Laszlo