mkinitrd-magellan/isolinux/rawcon.inc

;
; writechr:	Write a single character in AL to the console without
;		mangling any registers.  This does raw console writes,
;		since some PXE BIOSes seem to interfere regular console I/O.
;
%if IS_ISOLINUX
writechr_full:
%else
writechr:
%endif
		push ds
		push cs
		pop ds
		call write_serial	; write to serial port if needed
		pushfd
		test byte [DisplayCon],01h	; Write to screen?
		jz .nothing

		pushad
		mov bh,[BIOS_page]
		push ax
                mov ah,03h              ; Read cursor position
                int 10h
		pop ax
		cmp al,8
		je .bs
		cmp al,13
		je .cr
		cmp al,10
		je .lf
		push dx
                mov bh,[BIOS_page]
		mov bl,07h		; White on black
		mov cx,1		; One only
		mov ah,09h		; Write char and attribute
		int 10h
		pop dx
		inc dl
		cmp dl,[VidCols]
		jna .curxyok
		xor dl,dl
.lf:		inc dh
		cmp dh,[VidRows]
		ja .scroll
.curxyok:	mov bh,[BIOS_page]
		mov ah,02h		; Set cursor position
		int 10h			
.ret:		popad
.nothing:
		popfd
		pop ds
		ret
.scroll:	dec dh
		mov bh,[BIOS_page]
		mov ah,02h
		int 10h
		mov ax,0601h		; Scroll up one line
		mov bh,[ScrollAttribute]
		xor cx,cx
		mov dx,[ScreenSize]	; The whole screen
		int 10h
		jmp short .ret
.cr:		xor dl,dl
		jmp short .curxyok
.bs:		sub dl,1
		jnc .curxyok
		mov dl,[VidCols]
		sub dh,1
		jnc .curxyok
		xor dh,dh
		jmp short .curxyok

1	niro	532	;
2			; writechr: Write a single character in AL to the console without
3			; mangling any registers. This does raw console writes,
4			; since some PXE BIOSes seem to interfere regular console I/O.
5			;
6			%if IS_ISOLINUX
7			writechr_full:
8			%else
9			writechr:
10			%endif
11			push ds
12			push cs
13			pop ds
14			call write_serial ; write to serial port if needed
15			pushfd
16			test byte [DisplayCon],01h ; Write to screen?
17			jz .nothing
18
19			pushad
20			mov bh,[BIOS_page]
21			push ax
22			mov ah,03h ; Read cursor position
23			int 10h
24			pop ax
25			cmp al,8
26			je .bs
27			cmp al,13
28			je .cr
29			cmp al,10
30			je .lf
31			push dx
32			mov bh,[BIOS_page]
33			mov bl,07h ; White on black
34			mov cx,1 ; One only
35			mov ah,09h ; Write char and attribute
36			int 10h
37			pop dx
38			inc dl
39			cmp dl,[VidCols]
40			jna .curxyok
41			xor dl,dl
42			.lf: inc dh
43			cmp dh,[VidRows]
44			ja .scroll
45			.curxyok: mov bh,[BIOS_page]
46			mov ah,02h ; Set cursor position
47			int 10h
48			.ret: popad
49			.nothing:
50			popfd
51			pop ds
52			ret
53			.scroll: dec dh
54			mov bh,[BIOS_page]
55			mov ah,02h
56			int 10h
57			mov ax,0601h ; Scroll up one line
58			mov bh,[ScrollAttribute]
59			xor cx,cx
60			mov dx,[ScreenSize] ; The whole screen
61			int 10h
62			jmp short .ret
63			.cr: xor dl,dl
64			jmp short .curxyok
65			.bs: sub dl,1
66			jnc .curxyok
67			mov dl,[VidCols]
68			sub dh,1
69			jnc .curxyok
70			xor dh,dh
71			jmp short .curxyok
72