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| author | Gerd Hoffmann <kraxel@redhat.com> | 2022-09-07 11:15:04 +0200 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2022-09-07 09:36:16 +0000 |
| commit | 512042eba87ff97a4820a55cf3b1a89a8afd1cc7 (patch) | |
| tree | 0e60ebfbfbf641c6e2f93d2f044ae3bf90c671d9 /UefiPayloadPkg | |
| parent | 314799a926938a630e96aa659a132d3c33319331 (diff) | |
| download | edk2-512042eba87ff97a4820a55cf3b1a89a8afd1cc7.tar.gz edk2-512042eba87ff97a4820a55cf3b1a89a8afd1cc7.tar.bz2 edk2-512042eba87ff97a4820a55cf3b1a89a8afd1cc7.zip | |
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>
Diffstat (limited to 'UefiPayloadPkg')
0 files changed, 0 insertions, 0 deletions