Changeset 23186 in vbox

Timestamp:

Sep 21, 2009 12:45:22 PM (15 years ago)

Author:

vboxsync

Message:

DevPCI: Workaround needed for EFI is the right thing to do, enabled always and added explanatory comment.

File:

• trunk/src/VBox/Devices/Bus/DevPCI.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Bus/DevPCI.cpp

@@ -933 +933 @@
                 /* VGA: map frame buffer to default Bochs VBE address */
                 pci_set_io_region_addr(pGlobals, uBus, uDevFn, 0, 0xE0000000);
-#ifdef VBOX_WITH_EFI
-                /* The following is necessary for the VGA check in
-                   PciVgaMiniPortDriverBindingSupported to succeed. */
-                /** @todo Seems we're missing some I/O registers or something on the VGA device... Compare real/virt hw with lspci. */
-                pci_config_writew(pGlobals, uBus, uDevFn, PCI_COMMAND,
-                                  pci_config_readw(pGlobals, uBus, uDevFn, PCI_COMMAND)
+                /* 
+                 * Legacy VGA I/O ports are implicitly decoded by a VGA class device. But
+                 * only the framebuffer (i.e., a memory region) is explicitly registered via
+                 * pci_set_io_region_addr, so I/O decoding must be enabled manually.
+                 */
+                pci_config_writeb(pGlobals, uBus, uDevFn, PCI_COMMAND,
+                                  pci_config_readb(pGlobals, uBus, uDevFn, PCI_COMMAND)
                                   | 1 /* Enable I/O space access. */);
-#endif
                 break;
             case 0x0800: