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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - arch/x86/boot/video-vga.c
1 /* -*- linux-c -*- ------------------------------------------------------- *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 * Copyright 2009 Intel Corporation; author H. Peter Anvin
7 * This file is part of the Linux kernel, and is made available under
8 * the terms of the GNU General Public License version 2.
10 * ----------------------------------------------------------------------- */
13 * Common all-VGA modes
19 static struct mode_info vga_modes
[] = {
20 { VIDEO_80x25
, 80, 25, 0 },
21 { VIDEO_8POINT
, 80, 50, 0 },
22 { VIDEO_80x43
, 80, 43, 0 },
23 { VIDEO_80x28
, 80, 28, 0 },
24 { VIDEO_80x30
, 80, 30, 0 },
25 { VIDEO_80x34
, 80, 34, 0 },
26 { VIDEO_80x60
, 80, 60, 0 },
29 static struct mode_info ega_modes
[] = {
30 { VIDEO_80x25
, 80, 25, 0 },
31 { VIDEO_8POINT
, 80, 43, 0 },
34 static struct mode_info cga_modes
[] = {
35 { VIDEO_80x25
, 80, 25, 0 },
38 static __videocard video_vga
;
40 /* Set basic 80x25 mode */
41 static u8
vga_set_basic_mode(void)
43 struct biosregs ireg
, oreg
;
48 /* Query current mode */
50 intcall(0x10, &ireg
, &oreg
);
53 if (mode
!= 3 && mode
!= 7)
57 ireg
.ax
= mode
; /* AH=0: set mode */
58 intcall(0x10, &ireg
, NULL
);
63 static void vga_set_8font(void)
65 /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
73 intcall(0x10, &ireg
, NULL
);
75 /* Use alternate print screen */
78 intcall(0x10, &ireg
, NULL
);
80 /* Turn off cursor emulation */
83 intcall(0x10, &ireg
, NULL
);
85 /* Cursor is scan lines 6-7 */
88 intcall(0x10, &ireg
, NULL
);
91 static void vga_set_14font(void)
93 /* Set 9x14 font - 80x28 on VGA */
101 intcall(0x10, &ireg
, NULL
);
103 /* Turn off cursor emulation */
106 intcall(0x10, &ireg
, NULL
);
108 /* Cursor is scan lines 11-12 */
111 intcall(0x10, &ireg
, NULL
);
114 static void vga_set_80x43(void)
116 /* Set 80x43 mode on VGA (not EGA) */
117 struct biosregs ireg
;
124 intcall(0x10, &ireg
, NULL
);
126 /* Reset video mode */
128 intcall(0x10, &ireg
, NULL
);
133 /* I/O address of the VGA CRTC */
136 return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
139 static void vga_set_480_scanlines(void)
141 u16 crtc
; /* CRTC base address */
142 u8 csel
; /* CRTC miscellaneous output register */
146 out_idx(0x0c, crtc
, 0x11); /* Vertical sync end, unlock CR0-7 */
147 out_idx(0x0b, crtc
, 0x06); /* Vertical total */
148 out_idx(0x3e, crtc
, 0x07); /* Vertical overflow */
149 out_idx(0xea, crtc
, 0x10); /* Vertical sync start */
150 out_idx(0xdf, crtc
, 0x12); /* Vertical display end */
151 out_idx(0xe7, crtc
, 0x15); /* Vertical blank start */
152 out_idx(0x04, crtc
, 0x16); /* Vertical blank end */
159 static void vga_set_vertical_end(int lines
)
161 u16 crtc
; /* CRTC base address */
162 u8 ovfw
; /* CRTC overflow register */
167 ovfw
= 0x3c | ((end
>> (8-1)) & 0x02) | ((end
>> (9-6)) & 0x40);
169 out_idx(ovfw
, crtc
, 0x07); /* Vertical overflow */
170 out_idx(end
, crtc
, 0x12); /* Vertical display end */
173 static void vga_set_80x30(void)
175 vga_set_480_scanlines();
176 vga_set_vertical_end(30*16);
179 static void vga_set_80x34(void)
181 vga_set_480_scanlines();
183 vga_set_vertical_end(34*14);
186 static void vga_set_80x60(void)
188 vga_set_480_scanlines();
190 vga_set_vertical_end(60*8);
193 static int vga_set_mode(struct mode_info
*mode
)
195 /* Set the basic mode */
196 vga_set_basic_mode();
198 /* Override a possibly broken BIOS */
202 switch (mode
->mode
) {
229 * Note: this probe includes basic information required by all
230 * systems. It should be executed first, by making sure
231 * video-vga.c is listed first in the Makefile.
233 static int vga_probe(void)
235 static const char *card_name
[] = {
236 "CGA/MDA/HGC", "EGA", "VGA"
238 static struct mode_info
*mode_lists
[] = {
243 static int mode_count
[] = {
244 sizeof(cga_modes
)/sizeof(struct mode_info
),
245 sizeof(ega_modes
)/sizeof(struct mode_info
),
246 sizeof(vga_modes
)/sizeof(struct mode_info
),
249 struct biosregs ireg
, oreg
;
254 ireg
.bl
= 0x10; /* Check EGA/VGA */
255 intcall(0x10, &ireg
, &oreg
);
258 boot_params
.screen_info
.orig_video_ega_bx
= oreg
.bx
;
261 /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
262 if (oreg
.bl
!= 0x10) {
265 intcall(0x10, &ireg
, &oreg
);
267 if (oreg
.al
== 0x1a) {
268 adapter
= ADAPTER_VGA
;
270 boot_params
.screen_info
.orig_video_isVGA
= 1;
273 adapter
= ADAPTER_EGA
;
276 adapter
= ADAPTER_CGA
;
279 video_vga
.modes
= mode_lists
[adapter
];
280 video_vga
.card_name
= card_name
[adapter
];
281 return mode_count
[adapter
];
284 static __videocard video_vga
= {
287 .set_mode
= vga_set_mode
,