diff options
Diffstat (limited to 'OvmfPkg/QemuVideoDxe/VbeShim.c')
| -rw-r--r-- | OvmfPkg/QemuVideoDxe/VbeShim.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/OvmfPkg/QemuVideoDxe/VbeShim.c b/OvmfPkg/QemuVideoDxe/VbeShim.c new file mode 100644 index 0000000000..ae25b644cf --- /dev/null +++ b/OvmfPkg/QemuVideoDxe/VbeShim.c @@ -0,0 +1,275 @@ +/** @file
+ Install a fake VGABIOS service handler (real mode Int10h) for the buggy
+ Windows 2008 R2 SP1 UEFI guest.
+
+ The handler is never meant to be directly executed by a VCPU; it's there for
+ the internal real mode emulator of Windows 2008 R2 SP1.
+
+ The code is based on Ralf Brown's Interrupt List:
+ <http://www.cs.cmu.edu/~ralf/files.html>
+ <http://www.ctyme.com/rbrown.htm>
+
+ Copyright (C) 2014, Red Hat, Inc.
+ Copyright (c) 2013 - 2014, Intel Corporation. All rights reserved.<BR>
+
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+
+#include <IndustryStandard/LegacyVgaBios.h>
+#include <Library/DebugLib.h>
+#include <Library/PciLib.h>
+#include <Library/PrintLib.h>
+
+#include "Qemu.h"
+#include "VbeShim.h"
+
+#pragma pack (1)
+typedef struct {
+ UINT16 Offset;
+ UINT16 Segment;
+} IVT_ENTRY;
+#pragma pack ()
+
+//
+// This string is displayed by Windows 2008 R2 SP1 in the Screen Resolution,
+// Advanced Settings dialog. It should be short.
+//
+STATIC CONST CHAR8 mProductRevision[] = "OVMF Int10h (fake)";
+
+/**
+ Install the VBE Info and VBE Mode Info structures, and the VBE service
+ handler routine in the C segment. Point the real-mode Int10h interrupt vector
+ to the handler. The only advertised mode is 1024x768x32.
+
+ @param[in] CardName Name of the video card to be exposed in the
+ Product Name field of the VBE Info structure. The
+ parameter must originate from a
+ QEMU_VIDEO_CARD.Name field.
+ @param[in] FrameBufferBase Guest-physical base address of the video card's
+ frame buffer.
+**/
+VOID
+InstallVbeShim (
+ IN CONST CHAR16 *CardName,
+ IN EFI_PHYSICAL_ADDRESS FrameBufferBase
+ )
+{
+ EFI_PHYSICAL_ADDRESS Segment0, SegmentC, SegmentF;
+ UINTN Segment0Pages;
+ IVT_ENTRY *Int0x10;
+ EFI_STATUS Status;
+ UINTN Pam1Address;
+ UINT8 Pam1;
+ UINTN SegmentCPages;
+ VBE_INFO *VbeInfoFull;
+ VBE_INFO_BASE *VbeInfo;
+ UINT8 *Ptr;
+ UINTN Printed;
+ VBE_MODE_INFO *VbeModeInfo;
+
+ Segment0 = 0x00000;
+ SegmentC = 0xC0000;
+ SegmentF = 0xF0000;
+
+ //
+ // Attempt to cover the real mode IVT with an allocation. This is a UEFI
+ // driver, hence the arch protocols have been installed previously. Among
+ // those, the CPU arch protocol has configured the IDT, so we can overwrite
+ // the IVT used in real mode.
+ //
+ // The allocation request may fail, eg. if LegacyBiosDxe has already run.
+ //
+ Segment0Pages = 1;
+ Int0x10 = (IVT_ENTRY *)(UINTN)Segment0 + 0x10;
+ Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode,
+ Segment0Pages, &Segment0);
+
+ if (EFI_ERROR (Status)) {
+ EFI_PHYSICAL_ADDRESS Handler;
+
+ //
+ // Check if a video BIOS handler has been installed previously -- we
+ // shouldn't override a real video BIOS with our shim, nor our own shim if
+ // it's already present.
+ //
+ Handler = (Int0x10->Segment << 4) + Int0x10->Offset;
+ if (Handler >= SegmentC && Handler < SegmentF) {
+ DEBUG ((EFI_D_VERBOSE, "%a: Video BIOS handler found at %04x:%04x\n",
+ __FUNCTION__, Int0x10->Segment, Int0x10->Offset));
+ return;
+ }
+
+ //
+ // Otherwise we'll overwrite the Int10h vector, even though we may not own
+ // the page at zero.
+ //
+ DEBUG ((EFI_D_VERBOSE, "%a: failed to allocate page at zero: %r\n",
+ __FUNCTION__, Status));
+ } else {
+ //
+ // We managed to allocate the page at zero. SVN r14218 guarantees that it
+ // is NUL-filled.
+ //
+ ASSERT (Int0x10->Segment == 0x0000);
+ ASSERT (Int0x10->Offset == 0x0000);
+ }
+
+ //
+ // Put the shim in place first.
+ //
+ Pam1Address = PCI_LIB_ADDRESS (0, 0, 0, 0x5A);
+ //
+ // low nibble covers 0xC0000 to 0xC3FFF
+ // high nibble covers 0xC4000 to 0xC7FFF
+ // bit1 in each nibble is Write Enable
+ // bit0 in each nibble is Read Enable
+ //
+ Pam1 = PciRead8 (Pam1Address);
+ PciWrite8 (Pam1Address, Pam1 | (BIT1 | BIT0));
+
+ //
+ // We never added memory space durig PEI or DXE for the C segment, so we
+ // don't need to (and can't) allocate from there. Also, guest operating
+ // systems will see a hole in the UEFI memory map there.
+ //
+ SegmentCPages = 4;
+
+ ASSERT (sizeof mVbeShim <= EFI_PAGES_TO_SIZE (SegmentCPages));
+ CopyMem ((VOID *)(UINTN)SegmentC, mVbeShim, sizeof mVbeShim);
+
+ //
+ // Fill in the VBE INFO structure.
+ //
+ VbeInfoFull = (VBE_INFO *)(UINTN)SegmentC;
+ VbeInfo = &VbeInfoFull->Base;
+ Ptr = VbeInfoFull->Buffer;
+
+ CopyMem (VbeInfo->Signature, "VESA", 4);
+ VbeInfo->VesaVersion = 0x0300;
+
+ VbeInfo->OemNameAddress = (UINT32)(SegmentC << 12 | (UINT16)(UINTN)Ptr);
+ CopyMem (Ptr, "QEMU", 5);
+ Ptr += 5;
+
+ VbeInfo->Capabilities = BIT0; // DAC can be switched into 8-bit mode
+
+ VbeInfo->ModeListAddress = (UINT32)(SegmentC << 12 | (UINT16)(UINTN)Ptr);
+ *(UINT16*)Ptr = 0x00f1; // mode number
+ Ptr += 2;
+ *(UINT16*)Ptr = 0xFFFF; // mode list terminator
+ Ptr += 2;
+
+ VbeInfo->VideoMem64K = (UINT16)((1024 * 768 * 4 + 65535) / 65536);
+ VbeInfo->OemSoftwareVersion = 0x0000;
+
+ VbeInfo->VendorNameAddress = (UINT32)(SegmentC << 12 | (UINT16)(UINTN)Ptr);
+ CopyMem (Ptr, "OVMF", 5);
+ Ptr += 5;
+
+ VbeInfo->ProductNameAddress = (UINT32)(SegmentC << 12 | (UINT16)(UINTN)Ptr);
+ Printed = AsciiSPrint ((CHAR8 *)Ptr,
+ sizeof VbeInfoFull->Buffer - (Ptr - VbeInfoFull->Buffer), "%s",
+ CardName);
+ Ptr += Printed + 1;
+
+ VbeInfo->ProductRevAddress = (UINT32)(SegmentC << 12 | (UINT16)(UINTN)Ptr);
+ CopyMem (Ptr, mProductRevision, sizeof mProductRevision);
+ Ptr += sizeof mProductRevision;
+
+ ASSERT (sizeof VbeInfoFull->Buffer >= Ptr - VbeInfoFull->Buffer);
+ ZeroMem (Ptr, sizeof VbeInfoFull->Buffer - (Ptr - VbeInfoFull->Buffer));
+
+ //
+ // Fil in the VBE MODE INFO structure.
+ //
+ VbeModeInfo = (VBE_MODE_INFO *)(VbeInfoFull + 1);
+
+ //
+ // bit0: mode supported by present hardware configuration
+ // bit1: optional information available (must be =1 for VBE v1.2+)
+ // bit3: set if color, clear if monochrome
+ // bit4: set if graphics mode, clear if text mode
+ // bit5: mode is not VGA-compatible
+ // bit7: linear framebuffer mode supported
+ //
+ VbeModeInfo->ModeAttr = BIT7 | BIT5 | BIT4 | BIT3 | BIT1 | BIT0;
+
+ //
+ // bit0: exists
+ // bit1: bit1: readable
+ // bit2: writeable
+ //
+ VbeModeInfo->WindowAAttr = BIT2 | BIT1 | BIT0;
+
+ VbeModeInfo->WindowBAttr = 0x00;
+ VbeModeInfo->WindowGranularityKB = 0x0040;
+ VbeModeInfo->WindowSizeKB = 0x0040;
+ VbeModeInfo->WindowAStartSegment = 0xA000;
+ VbeModeInfo->WindowBStartSegment = 0x0000;
+ VbeModeInfo->WindowPositioningAddress = 0x0000;
+ VbeModeInfo->BytesPerScanLine = 1024 * 4;
+
+ VbeModeInfo->Width = 1024;
+ VbeModeInfo->Height = 768;
+ VbeModeInfo->CharCellWidth = 8;
+ VbeModeInfo->CharCellHeight = 16;
+ VbeModeInfo->NumPlanes = 1;
+ VbeModeInfo->BitsPerPixel = 32;
+ VbeModeInfo->NumBanks = 1;
+ VbeModeInfo->MemoryModel = 6; // direct color
+ VbeModeInfo->BankSizeKB = 0;
+ VbeModeInfo->NumImagePagesLessOne = 0;
+ VbeModeInfo->Vbe3 = 0x01;
+
+ VbeModeInfo->RedMaskSize = 8;
+ VbeModeInfo->RedMaskPos = 16;
+ VbeModeInfo->GreenMaskSize = 8;
+ VbeModeInfo->GreenMaskPos = 8;
+ VbeModeInfo->BlueMaskSize = 8;
+ VbeModeInfo->BlueMaskPos = 0;
+ VbeModeInfo->ReservedMaskSize = 8;
+ VbeModeInfo->ReservedMaskPos = 24;
+
+ //
+ // bit1: Bytes in reserved field may be used by application
+ //
+ VbeModeInfo->DirectColorModeInfo = BIT1;
+
+ VbeModeInfo->LfbAddress = (UINT32)FrameBufferBase;
+ VbeModeInfo->OffScreenAddress = 0;
+ VbeModeInfo->OffScreenSizeKB = 0;
+
+ VbeModeInfo->BytesPerScanLineLinear = 1024 * 4;
+ VbeModeInfo->NumImagesLessOneBanked = 0;
+ VbeModeInfo->NumImagesLessOneLinear = 0;
+ VbeModeInfo->RedMaskSizeLinear = 8;
+ VbeModeInfo->RedMaskPosLinear = 16;
+ VbeModeInfo->GreenMaskSizeLinear = 8;
+ VbeModeInfo->GreenMaskPosLinear = 8;
+ VbeModeInfo->BlueMaskSizeLinear = 8;
+ VbeModeInfo->BlueMaskPosLinear = 0;
+ VbeModeInfo->ReservedMaskSizeLinear = 8;
+ VbeModeInfo->ReservedMaskPosLinear = 24;
+ VbeModeInfo->MaxPixelClockHz = 0;
+
+ ZeroMem (VbeModeInfo->Reserved, sizeof VbeModeInfo->Reserved);
+
+ //
+ // Clear Write Enable (bit1), keep Read Enable (bit0) set
+ //
+ PciWrite8 (Pam1Address, (Pam1 & ~BIT1) | BIT0);
+
+ //
+ // Second, point the Int10h vector at the shim.
+ //
+ Int0x10->Segment = SegmentC >> 4;
+ Int0x10->Offset = (EFI_PHYSICAL_ADDRESS)(UINTN)(VbeModeInfo + 1) - SegmentC;
+
+ DEBUG ((EFI_D_INFO, "%a: VBE shim installed\n", __FUNCTION__));
+}
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