Fix Bug #1670509: wrong video attrs for int 10h, ah==13h The subroutine set_cursor_position is trashing %bx. Unfortunately, %bl contains the video attribute for write_string.
The fix saves %bx in the function prolog and restores it in the epilog. Signed-off-by: Herbie Robinson <herbie.robin...@stratus.com> --- Removed incorrect code deletions from set_current_cursor. Removed explanation of same from the commit message. BTW, I didn't see any test cases for this code, but if they exist and somebody points me at them, I should be able to generate a very small qcow2 file that demonstrates the problem. sgabios.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sgabios.S b/sgabios.S index 275d063..96c4e23 100644 --- a/sgabios.S +++ b/sgabios.S @@ -1728,6 +1728,7 @@ write_string_tail: set_cursor_position: pushw %ax + pushw %bx pushw %ds pushw $BDA_SEG popw %ds /* ds = 0x40 */ @@ -1738,6 +1739,7 @@ set_cursor_position: movw %ax, %bx /* bx = cursor save offset */ movw %dx, (%bx) /* save new cursor value */ popw %ds + popw %bx popw %ax ret -- 1.8.3.1
