| ; | |
| ; writechr: Write a single character in AL to the console without | |
| ; mangling any registers; handle video pages correctly. | |
| ; | |
| section .text | |
| writechr: | |
| call write_serial ; write to serial port if needed | |
| pushfd | |
| test byte [cs:UsingVGA], 08h | |
| jz .videook | |
| call vgaclearmode | |
| .videook: | |
| test byte [cs:DisplayCon], 01h | |
| jz .nothing | |
| pushad | |
| mov ah,0Eh | |
| mov bl,07h ; attribute | |
| mov bh,[cs:BIOS_page] ; current page | |
| int 10h | |
| popad | |
| .nothing: | |
| popfd | |
| ret |