xref: /linux/arch/x86/boot/video-vesa.c (revision be4ebf999a38dfe9d7d705c4913624ec816c48f2)
1 /* -*- linux-c -*- ------------------------------------------------------- *
2  *
3  *   Copyright (C) 1991, 1992 Linus Torvalds
4  *   Copyright 2007 rPath, Inc. - All Rights Reserved
5  *   Copyright 2009 Intel Corporation; author H. Peter Anvin
6  *
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.
9  *
10  * ----------------------------------------------------------------------- */
11 
12 /*
13  * VESA text modes
14  */
15 
16 #include "boot.h"
17 #include "video.h"
18 #include "vesa.h"
19 
20 /* VESA information */
21 static struct vesa_general_info vginfo;
22 static struct vesa_mode_info vminfo;
23 
24 static __videocard video_vesa;
25 
26 #ifndef _WAKEUP
27 static void vesa_store_mode_params_graphics(void);
28 #else /* _WAKEUP */
29 static inline void vesa_store_mode_params_graphics(void) {}
30 #endif /* _WAKEUP */
31 
32 static int vesa_probe(void)
33 {
34 #if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID)
35 	struct biosregs ireg, oreg;
36 	u16 mode;
37 	addr_t mode_ptr;
38 	struct mode_info *mi;
39 	int nmodes = 0;
40 
41 	video_vesa.modes = GET_HEAP(struct mode_info, 0);
42 
43 	initregs(&ireg);
44 	ireg.ax = 0x4f00;
45 	ireg.di = (size_t)&vginfo;
46 	intcall(0x10, &ireg, &oreg);
47 
48 	if (oreg.ax != 0x004f ||
49 	    vginfo.signature != VESA_MAGIC ||
50 	    vginfo.version < 0x0102)
51 		return 0;	/* Not present */
52 #endif /* CONFIG_VIDEO_VESA || CONFIG_FIRMWARE_EDID */
53 #ifdef CONFIG_VIDEO_VESA
54 	set_fs(vginfo.video_mode_ptr.seg);
55 	mode_ptr = vginfo.video_mode_ptr.off;
56 
57 	while ((mode = rdfs16(mode_ptr)) != 0xffff) {
58 		mode_ptr += 2;
59 
60 		if (!heap_free(sizeof(struct mode_info)))
61 			break;	/* Heap full, can't save mode info */
62 
63 		if (mode & ~0x1ff)
64 			continue;
65 
66 		memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
67 
68 		ireg.ax = 0x4f01;
69 		ireg.cx = mode;
70 		ireg.di = (size_t)&vminfo;
71 		intcall(0x10, &ireg, &oreg);
72 
73 		if (oreg.ax != 0x004f)
74 			continue;
75 
76 		if ((vminfo.mode_attr & 0x15) == 0x05) {
77 			/* Text Mode, TTY BIOS supported,
78 			   supported by hardware */
79 			mi = GET_HEAP(struct mode_info, 1);
80 			mi->mode  = mode + VIDEO_FIRST_VESA;
81 			mi->depth = 0; /* text */
82 			mi->x     = vminfo.h_res;
83 			mi->y     = vminfo.v_res;
84 			nmodes++;
85 		} else if ((vminfo.mode_attr & 0x99) == 0x99 &&
86 			   (vminfo.memory_layout == 4 ||
87 			    vminfo.memory_layout == 6) &&
88 			   vminfo.memory_planes == 1) {
89 #ifdef CONFIG_FB_BOOT_VESA_SUPPORT
90 			/* Graphics mode, color, linear frame buffer
91 			   supported.  Only register the mode if
92 			   if framebuffer is configured, however,
93 			   otherwise the user will be left without a screen. */
94 			mi = GET_HEAP(struct mode_info, 1);
95 			mi->mode = mode + VIDEO_FIRST_VESA;
96 			mi->depth = vminfo.bpp;
97 			mi->x = vminfo.h_res;
98 			mi->y = vminfo.v_res;
99 			nmodes++;
100 #endif
101 		}
102 	}
103 
104 	return nmodes;
105 #else
106 	return 0;
107 #endif /* CONFIG_VIDEO_VESA */
108 }
109 
110 static int vesa_set_mode(struct mode_info *mode)
111 {
112 	struct biosregs ireg, oreg;
113 	int is_graphic;
114 	u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
115 
116 	memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
117 
118 	initregs(&ireg);
119 	ireg.ax = 0x4f01;
120 	ireg.cx = vesa_mode;
121 	ireg.di = (size_t)&vminfo;
122 	intcall(0x10, &ireg, &oreg);
123 
124 	if (oreg.ax != 0x004f)
125 		return -1;
126 
127 	if ((vminfo.mode_attr & 0x15) == 0x05) {
128 		/* It's a supported text mode */
129 		is_graphic = 0;
130 #ifdef CONFIG_FB_BOOT_VESA_SUPPORT
131 	} else if ((vminfo.mode_attr & 0x99) == 0x99) {
132 		/* It's a graphics mode with linear frame buffer */
133 		is_graphic = 1;
134 		vesa_mode |= 0x4000; /* Request linear frame buffer */
135 #endif
136 	} else {
137 		return -1;	/* Invalid mode */
138 	}
139 
140 
141 	initregs(&ireg);
142 	ireg.ax = 0x4f02;
143 	ireg.bx = vesa_mode;
144 	intcall(0x10, &ireg, &oreg);
145 
146 	if (oreg.ax != 0x004f)
147 		return -1;
148 
149 	graphic_mode = is_graphic;
150 	if (!is_graphic) {
151 		/* Text mode */
152 		force_x = mode->x;
153 		force_y = mode->y;
154 		do_restore = 1;
155 	} else {
156 		/* Graphics mode */
157 		vesa_store_mode_params_graphics();
158 	}
159 
160 	return 0;
161 }
162 
163 
164 #ifndef _WAKEUP
165 
166 /* Switch DAC to 8-bit mode */
167 static void vesa_dac_set_8bits(void)
168 {
169 	struct biosregs ireg, oreg;
170 	u8 dac_size = 6;
171 
172 	/* If possible, switch the DAC to 8-bit mode */
173 	if (vginfo.capabilities & 1) {
174 		initregs(&ireg);
175 		ireg.ax = 0x4f08;
176 		ireg.bh = 0x08;
177 		intcall(0x10, &ireg, &oreg);
178 		if (oreg.ax == 0x004f)
179 			dac_size = oreg.bh;
180 	}
181 
182 	/* Set the color sizes to the DAC size, and offsets to 0 */
183 	boot_params.screen_info.red_size   = dac_size;
184 	boot_params.screen_info.green_size = dac_size;
185 	boot_params.screen_info.blue_size  = dac_size;
186 	boot_params.screen_info.rsvd_size  = dac_size;
187 
188 	boot_params.screen_info.red_pos    = 0;
189 	boot_params.screen_info.green_pos  = 0;
190 	boot_params.screen_info.blue_pos   = 0;
191 	boot_params.screen_info.rsvd_pos   = 0;
192 }
193 
194 /* Save the VESA protected mode info */
195 static void vesa_store_pm_info(void)
196 {
197 	struct biosregs ireg, oreg;
198 
199 	initregs(&ireg);
200 	ireg.ax = 0x4f0a;
201 	intcall(0x10, &ireg, &oreg);
202 
203 	if (oreg.ax != 0x004f)
204 		return;
205 
206 	boot_params.screen_info.vesapm_seg = oreg.es;
207 	boot_params.screen_info.vesapm_off = oreg.di;
208 }
209 
210 /*
211  * Save video mode parameters for graphics mode
212  */
213 static void vesa_store_mode_params_graphics(void)
214 {
215 	/* Tell the kernel we're in VESA graphics mode */
216 	boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
217 
218 	/* Mode parameters */
219 	boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
220 	boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
221 	boot_params.screen_info.lfb_width = vminfo.h_res;
222 	boot_params.screen_info.lfb_height = vminfo.v_res;
223 	boot_params.screen_info.lfb_depth = vminfo.bpp;
224 	boot_params.screen_info.pages = vminfo.image_planes;
225 	boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
226 	memcpy(&boot_params.screen_info.red_size,
227 	       &vminfo.rmask, 8);
228 
229 	/* General parameters */
230 	boot_params.screen_info.lfb_size = vginfo.total_memory;
231 
232 	if (vminfo.bpp <= 8)
233 		vesa_dac_set_8bits();
234 
235 	vesa_store_pm_info();
236 }
237 
238 /*
239  * Save EDID information for the kernel; this is invoked, separately,
240  * after mode-setting.
241  */
242 void vesa_store_edid(void)
243 {
244 #ifdef CONFIG_FIRMWARE_EDID
245 	struct biosregs ireg, oreg;
246 
247 	/* Apparently used as a nonsense token... */
248 	memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
249 
250 	if (vginfo.version < 0x0200)
251 		return;		/* EDID requires VBE 2.0+ */
252 
253 	initregs(&ireg);
254 	ireg.ax = 0x4f15;		/* VBE DDC */
255 	/* ireg.bx = 0x0000; */		/* Report DDC capabilities */
256 	/* ireg.cx = 0;	*/		/* Controller 0 */
257 	ireg.es = 0;			/* ES:DI must be 0 by spec */
258 	intcall(0x10, &ireg, &oreg);
259 
260 	if (oreg.ax != 0x004f)
261 		return;		/* No EDID */
262 
263 	/* BH = time in seconds to transfer EDD information */
264 	/* BL = DDC level supported */
265 
266 	ireg.ax = 0x4f15;		/* VBE DDC */
267 	ireg.bx = 0x0001;		/* Read EDID */
268 	/* ireg.cx = 0; */		/* Controller 0 */
269 	/* ireg.dx = 0;	*/		/* EDID block number */
270 	ireg.es = ds();
271 	ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
272 	intcall(0x10, &ireg, &oreg);
273 #endif /* CONFIG_FIRMWARE_EDID */
274 }
275 
276 #endif /* not _WAKEUP */
277 
278 static __videocard video_vesa =
279 {
280 	.card_name	= "VESA",
281 	.probe		= vesa_probe,
282 	.set_mode	= vesa_set_mode,
283 	.xmode_first	= VIDEO_FIRST_VESA,
284 	.xmode_n	= 0x200,
285 };
286