The highest VBE_DISPI_INDEX_ID version supported by QEMU is
VBE_DISPI_ID5. But currently QEMU only allows writing values up to
VBE_DISPI_ID4 to the VBE_DISPI_INDEX_ID register.
As a result of this when a lower version is written to this register and
later VBE_DISPI_ID5 is written back, reads from the register will
continue to report the lower version.
Indeed SeaBIOS is doing that during VGA initialization which causes
guests to always read VBE_DISPI_ID0 instead of the correct version.
Signed-off-by: Dennis Wölfing <denniswoelfing@gmx.de>
---
hw/display/vga.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/hw/display/vga.c b/hw/display/vga.c
index 28a90e30d0..9d1f66af40 100644
--- a/hw/display/vga.c
+++ b/hw/display/vga.c
@@ -752,7 +752,8 @@ void vbe_ioport_write_data(void *opaque, uint32_t addr,
uint32_t val)
val == VBE_DISPI_ID1 ||
val == VBE_DISPI_ID2 ||
val == VBE_DISPI_ID3 ||
- val == VBE_DISPI_ID4) {
+ val == VBE_DISPI_ID4 ||
+ val == VBE_DISPI_ID5) {
s->vbe_regs[s->vbe_index] = val;
}
break;
--
2.31.1