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authorGerd Hoffmann <kraxel@redhat.com>2022-09-07 11:15:04 +0200
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2022-09-07 09:36:16 +0000
commit512042eba87ff97a4820a55cf3b1a89a8afd1cc7 (patch)
tree0e60ebfbfbf641c6e2f93d2f044ae3bf90c671d9
parent314799a926938a630e96aa659a132d3c33319331 (diff)
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OvmfPkg/QemuVideoDxe: fix bochs mode init
Add VgaInb() helper function to read vga registers. With that in place fix the unblanking. We need to put the ATT_ADDRESS_REGISTER flip flop into a known state, which is done by reading the INPUT_STATUS_1_REGISTER. Reading the INPUT_STATUS_1_REGISTER only works when the device is in color mode, so make sure that bit (0x01) is set in MISC_OUTPUT_REGISTER. Currently the mode setting works more by luck because ATT_ADDRESS_REGISTER flip flop happens to be in the state we need. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
-rw-r--r--OvmfPkg/QemuVideoDxe/Driver.c34
1 files changed, 33 insertions, 1 deletions
diff --git a/OvmfPkg/QemuVideoDxe/Driver.c b/OvmfPkg/QemuVideoDxe/Driver.c
index b91909a14e..c28171d137 100644
--- a/OvmfPkg/QemuVideoDxe/Driver.c
+++ b/OvmfPkg/QemuVideoDxe/Driver.c
@@ -984,6 +984,34 @@ VgaOutb (
}
}
+STATIC
+UINT8
+VgaInb (
+ QEMU_VIDEO_PRIVATE_DATA *Private,
+ UINTN Reg
+ )
+{
+ EFI_STATUS Status;
+ UINT8 Data;
+
+ if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO) {
+ Data = 0;
+ Status = Private->PciIo->Mem.Read (
+ Private->PciIo,
+ EfiPciIoWidthUint8,
+ PCI_BAR_IDX2,
+ 0x400 - 0x3c0 + Reg,
+ 1,
+ &Data
+ );
+ ASSERT_EFI_ERROR (Status);
+ } else {
+ Data = inb (Private, Reg);
+ }
+
+ return Data;
+}
+
VOID
InitializeBochsGraphicsMode (
QEMU_VIDEO_PRIVATE_DATA *Private,
@@ -998,7 +1026,11 @@ InitializeBochsGraphicsMode (
ModeData->ColorDepth
));
- /* unblank */
+ /* set color mode */
+ VgaOutb (Private, MISC_OUTPUT_REGISTER, 0x01);
+
+ /* reset flip flop + unblank */
+ VgaInb (Private, INPUT_STATUS_1_REGISTER);
VgaOutb (Private, ATT_ADDRESS_REGISTER, 0x20);
BochsWrite (Private, VBE_DISPI_INDEX_ENABLE, 0);