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 <kra...@redhat.com>
---
OvmfPkg/QemuVideoDxe/Driver.c | 33 ++++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/OvmfPkg/QemuVideoDxe/Driver.c b/OvmfPkg/QemuVideoDxe/Driver.c
index b91909a14e59..1f9ba046ef04 100644
--- a/OvmfPkg/QemuVideoDxe/Driver.c
+++ b/OvmfPkg/QemuVideoDxe/Driver.c
@@ -984,6 +984,33 @@ VgaOutb (
}
}
+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 +1025,11 @@ 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);
--
2.37.3
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#93371): https://edk2.groups.io/g/devel/message/93371
Mute This Topic: https://groups.io/mt/93521129/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
