mkinitrd-magellan/isolinux/font.inc

;; $Id: font.inc,v 1.1 2007-09-01 22:44:04 niro Exp $
;; -----------------------------------------------------------------------
;;   
;;   Copyright 1994-2004 H. Peter Anvin - All Rights Reserved
;;
;;   This program is free software; you can redistribute it and/or modify
;;   it under the terms of the GNU General Public License as published by
;;   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
;;   Boston MA 02111-1307, USA; either version 2 of the License, or
;;   (at your option) any later version; incorporated herein by reference.
;;
;; -----------------------------------------------------------------------

;;
;; font.inc
;;
;; VGA font handling code
;;

		section .text

;
; loadfont:	Load a .psf font file and install it onto the VGA console
;		(if we're not on a VGA screen then ignore.)  It is called with
;		SI and DX:AX set by routine searchdir
;
loadfont:
		mov bx,trackbuf			; The trackbuf is >= 16K; the part
		mov cx,[BufSafe]		; of a PSF file we care about is no
		call getfssec			; more than 8K+4 bytes

		mov ax,[trackbuf]		; Magic number
		cmp ax,0436h
		jne lf_ret

		mov al,[trackbuf+2]		; File mode
		cmp al,5			; Font modes 0-5 supported
		ja lf_ret

		mov bh,byte [trackbuf+3]	; Height of font
		cmp bh,2			; VGA minimum
		jb lf_ret
		cmp bh,32			; VGA maximum
		ja lf_ret

		; Copy to font buffer
		mov si,trackbuf+4		; Start of font data
		mov [VGAFontSize],bh
		mov di,vgafontbuf
		mov cx,(32*256) >> 2		; Maximum size
		rep movsd

		mov [UserFont], byte 1		; Set font flag

		; Fall through to use_font

;
; use_font:
; 	This routine activates whatever font happens to be in the
;	vgafontbuf, and updates the adjust_screen data.
;       Must be called with CS = DS = ES
;
use_font:
		test [UserFont], byte 1		; Are we using a user-specified font?
		jz adjust_screen		; If not, just do the normal stuff

		mov bp,vgafontbuf
		mov bh,[VGAFontSize]

		xor bl,bl			; Needed by both INT 10h calls
		cmp [UsingVGA], byte 1		; Are we in graphics mode?
		jne .text

.graphics:
		xor cx,cx
		mov cl,bh			; CX = bytes/character
		mov ax,480
		div cl				; Compute char rows per screen
		mov dl,al
		dec al
		mov [VidRows],al
		mov ax,1121h			; Set user character table
		int 10h
		mov [VidCols], byte 79		; Always 80 bytes/line
.lf_ret:	ret				; No need to call adjust_screen

.text:
		mov cx,256
		xor dx,dx
		mov ax,1110h
		int 10h				; Load into VGA RAM

		xor bl,bl
		mov ax,1103h			; Select page 0
		int 10h

		; Fall through to adjust_screen

lf_ret		equ use_font.lf_ret

;
; adjust_screen: Set the internal variables associated with the screen size.
;		This is a subroutine in case we're loading a custom font.
;
adjust_screen:
		pusha
                mov al,[BIOS_vidrows]
                and al,al
                jnz vidrows_ok
                mov al,24                       ; No vidrows in BIOS, assume 25
						; (Remember: vidrows == rows-1)
vidrows_ok:	mov [VidRows],al
                mov ah,0fh
                int 10h                         ; Read video state
                dec ah                          ; Store count-1 (same as rows)
                mov [VidCols],ah
		popa
		ret

		
; VGA font buffer at the end of memory (so loading a font works even
; in graphics mode, but don't put too much pressure on the .bss)
		section .latebss
vgafontbuf	resb 8192

		section .data
		align 2, db 0
VGAFontSize	dw 16			; Defaults to 16 byte font
UserFont	db 0			; Using a user-specified font


1	niro	532	;; $Id: font.inc,v 1.1 2007-09-01 22:44:04 niro Exp $
2			;; -----------------------------------------------------------------------
3			;;
4			;; Copyright 1994-2004 H. Peter Anvin - All Rights Reserved
5			;;
6			;; This program is free software; you can redistribute it and/or modify
7			;; it under the terms of the GNU General Public License as published by
8			;; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
9			;; Boston MA 02111-1307, USA; either version 2 of the License, or
10			;; (at your option) any later version; incorporated herein by reference.
11			;;
12			;; -----------------------------------------------------------------------
13
14			;;
15			;; font.inc
16			;;
17			;; VGA font handling code
18			;;
19
20			section .text
21
22			;
23			; loadfont: Load a .psf font file and install it onto the VGA console
24			; (if we're not on a VGA screen then ignore.) It is called with
25			; SI and DX:AX set by routine searchdir
26			;
27			loadfont:
28			mov bx,trackbuf ; The trackbuf is >= 16K; the part
29			mov cx,[BufSafe] ; of a PSF file we care about is no
30			call getfssec ; more than 8K+4 bytes
31
32			mov ax,[trackbuf] ; Magic number
33			cmp ax,0436h
34			jne lf_ret
35
36			mov al,[trackbuf+2] ; File mode
37			cmp al,5 ; Font modes 0-5 supported
38			ja lf_ret
39
40			mov bh,byte [trackbuf+3] ; Height of font
41			cmp bh,2 ; VGA minimum
42			jb lf_ret
43			cmp bh,32 ; VGA maximum
44			ja lf_ret
45
46			; Copy to font buffer
47			mov si,trackbuf+4 ; Start of font data
48			mov [VGAFontSize],bh
49			mov di,vgafontbuf
50			mov cx,(32*256) >> 2 ; Maximum size
51			rep movsd
52
53			mov [UserFont], byte 1 ; Set font flag
54
55			; Fall through to use_font
56
57			;
58			; use_font:
59			; This routine activates whatever font happens to be in the
60			; vgafontbuf, and updates the adjust_screen data.
61			; Must be called with CS = DS = ES
62			;
63			use_font:
64			test [UserFont], byte 1 ; Are we using a user-specified font?
65			jz adjust_screen ; If not, just do the normal stuff
66
67			mov bp,vgafontbuf
68			mov bh,[VGAFontSize]
69
70			xor bl,bl ; Needed by both INT 10h calls
71			cmp [UsingVGA], byte 1 ; Are we in graphics mode?
72			jne .text
73
74			.graphics:
75			xor cx,cx
76			mov cl,bh ; CX = bytes/character
77			mov ax,480
78			div cl ; Compute char rows per screen
79			mov dl,al
80			dec al
81			mov [VidRows],al
82			mov ax,1121h ; Set user character table
83			int 10h
84			mov [VidCols], byte 79 ; Always 80 bytes/line
85			.lf_ret: ret ; No need to call adjust_screen
86
87			.text:
88			mov cx,256
89			xor dx,dx
90			mov ax,1110h
91			int 10h ; Load into VGA RAM
92
93			xor bl,bl
94			mov ax,1103h ; Select page 0
95			int 10h
96
97			; Fall through to adjust_screen
98
99			lf_ret equ use_font.lf_ret
100
101			;
102			; adjust_screen: Set the internal variables associated with the screen size.
103			; This is a subroutine in case we're loading a custom font.
104			;
105			adjust_screen:
106			pusha
107			mov al,[BIOS_vidrows]
108			and al,al
109			jnz vidrows_ok
110			mov al,24 ; No vidrows in BIOS, assume 25
111			; (Remember: vidrows == rows-1)
112			vidrows_ok: mov [VidRows],al
113			mov ah,0fh
114			int 10h ; Read video state
115			dec ah ; Store count-1 (same as rows)
116			mov [VidCols],ah
117			popa
118			ret
119
120
121			; VGA font buffer at the end of memory (so loading a font works even
122			; in graphics mode, but don't put too much pressure on the .bss)
123			section .latebss
124			vgafontbuf resb 8192
125
126			section .data
127			align 2, db 0
128			VGAFontSize dw 16 ; Defaults to 16 byte font
129			UserFont db 0 ; Using a user-specified font
130
131