From 947f3737abf65fda63f3ffd97fddfa6986986868 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Tue, 19 Sep 2017 17:05:08 +0200 Subject: [PATCH] OvmfPkg/QemuVideoDxe/VbeShim: handle PAM1 register on Q35 correctly In commit db27e9f3d8f0 ("OvmfPkg/LegacyRegion: Support legacy region manipulation of Q35", 2016-03-15), Ray extended the OvmfPkg/Csm/CsmSupportLib PAM register manipulation to Q35. However, we missed that the same should be done to the QemuVideoDxe VBE Shim as well. The omission has caused no problems in practice on Q35, because QEMU has let us write to the ROM area, regardless of the PAM1 setting, all this time. This has now changed with recent QEMU commit 208fa0e43645 ("pc: make 'pc.rom' readonly when machine has PCI enabled", 2017-07-28). The QEMU commit exposes the OVMF bug when Windows 7 is started on Q35, using QEMU 2.10 -- the VBE Shim is no longer put in place and Windows 7 cannot find it. To remedy this, assign the "Pam1Address" local variable a PciLib address that matches the board type (i440fx vs. q35). Regarding the PcdLib dependency: QemuVideoDxe already uses PcdLib, both directly (see "PcdDriverSupportedEfiVersion") and indirectly (e.g. via the DxePciLibI440FxQ35 PciLib instance). Add PcdLib to [LibraryClasses] for completeness. Cc: Aleksei Kovura Cc: Gerd Hoffmann Cc: Igor Mammedov Cc: Jordan Justen Cc: Ruiyu Ni Ref: https://bugs.launchpad.net/qemu/+bug/1715700 Reported-by: Aleksei Kovura Special-thanks-to: Gerd Hoffmann Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek Tested-by: Aleksei Kovura Reviewed-by: Jordan Justen --- OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf | 3 ++- OvmfPkg/QemuVideoDxe/VbeShim.c | 27 ++++++++++++++++++++++++++- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf index 7c7d429bca..577e07b0a8 100644 --- a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf +++ b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf @@ -60,6 +60,7 @@ DebugLib DevicePathLib MemoryAllocationLib + PcdLib PciLib PrintLib TimerLib @@ -75,4 +76,4 @@ [Pcd] gOptionRomPkgTokenSpaceGuid.PcdDriverSupportedEfiVersion - + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId diff --git a/OvmfPkg/QemuVideoDxe/VbeShim.c b/OvmfPkg/QemuVideoDxe/VbeShim.c index bc90e06726..e45a08e887 100644 --- a/OvmfPkg/QemuVideoDxe/VbeShim.c +++ b/OvmfPkg/QemuVideoDxe/VbeShim.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "Qemu.h" #include "VbeShim.h" @@ -64,6 +65,7 @@ InstallVbeShim ( UINTN Segment0Pages; IVT_ENTRY *Int0x10; EFI_STATUS Segment0AllocationStatus; + UINT16 HostBridgeDevId; UINTN Pam1Address; UINT8 Pam1; UINTN SegmentCPages; @@ -131,7 +133,30 @@ InstallVbeShim ( // // Put the shim in place first. // - Pam1Address = PCI_LIB_ADDRESS (0, 0, 0, 0x5A); + // Start by determining the address of the PAM1 register. + // + HostBridgeDevId = PcdGet16 (PcdOvmfHostBridgePciDevId); + switch (HostBridgeDevId) { + case INTEL_82441_DEVICE_ID: + Pam1Address = PMC_REGISTER_PIIX4 (PIIX4_PAM1); + break; + case INTEL_Q35_MCH_DEVICE_ID: + Pam1Address = DRAMC_REGISTER_Q35 (MCH_PAM1); + break; + default: + DEBUG (( + DEBUG_ERROR, + "%a: unknown host bridge device ID: 0x%04x\n", + __FUNCTION__, + HostBridgeDevId + )); + ASSERT (FALSE); + + if (!EFI_ERROR (Segment0AllocationStatus)) { + gBS->FreePages (Segment0, Segment0Pages); + } + return; + } // // low nibble covers 0xC0000 to 0xC3FFF // high nibble covers 0xC4000 to 0xC7FFF -- 2.39.2