xref: /linux/arch/x86/boot/video-vesa.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 #include "string.h"
20 
21 /* VESA information */
22 static struct vesa_general_info vginfo;
23 static struct vesa_mode_info vminfo;
24 
25 static __videocard video_vesa;
26 
27 #ifndef _WAKEUP
28 static void vesa_store_mode_params_graphics(void);
29 #else /* _WAKEUP */
30 static inline void vesa_store_mode_params_graphics(void) {}
31 #endif /* _WAKEUP */
32 
33 static int vesa_probe(void)
34 {
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 
53 	set_fs(vginfo.video_mode_ptr.seg);
54 	mode_ptr = vginfo.video_mode_ptr.off;
55 
56 	while ((mode = rdfs16(mode_ptr)) != 0xffff) {
57 		mode_ptr += 2;
58 
59 		if (!heap_free(sizeof(struct mode_info)))
60 			break;	/* Heap full, can't save mode info */
61 
62 		if (mode & ~0x1ff)
63 			continue;
64 
65 		memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
66 
67 		ireg.ax = 0x4f01;
68 		ireg.cx = mode;
69 		ireg.di = (size_t)&vminfo;
70 		intcall(0x10, &ireg, &oreg);
71 
72 		if (oreg.ax != 0x004f)
73 			continue;
74 
75 		if ((vminfo.mode_attr & 0x15) == 0x05) {
76 			/* Text Mode, TTY BIOS supported,
77 			   supported by hardware */
78 			mi = GET_HEAP(struct mode_info, 1);
79 			mi->mode  = mode + VIDEO_FIRST_VESA;
80 			mi->depth = 0; /* text */
81 			mi->x     = vminfo.h_res;
82 			mi->y     = vminfo.v_res;
83 			nmodes++;
84 		} else if ((vminfo.mode_attr & 0x99) == 0x99 &&
85 			   (vminfo.memory_layout == 4 ||
86 			    vminfo.memory_layout == 6) &&
87 			   vminfo.memory_planes == 1) {
88 #ifdef CONFIG_FB_BOOT_VESA_SUPPORT
89 			/* Graphics mode, color, linear frame buffer
90 			   supported.  Only register the mode if
91 			   if framebuffer is configured, however,
92 			   otherwise the user will be left without a screen. */
93 			mi = GET_HEAP(struct mode_info, 1);
94 			mi->mode = mode + VIDEO_FIRST_VESA;
95 			mi->depth = vminfo.bpp;
96 			mi->x = vminfo.h_res;
97 			mi->y = vminfo.v_res;
98 			nmodes++;
99 #endif
100 		}
101 	}
102 
103 	return nmodes;
104 }
105 
106 static int vesa_set_mode(struct mode_info *mode)
107 {
108 	struct biosregs ireg, oreg;
109 	int is_graphic;
110 	u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
111 
112 	memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
113 
114 	initregs(&ireg);
115 	ireg.ax = 0x4f01;
116 	ireg.cx = vesa_mode;
117 	ireg.di = (size_t)&vminfo;
118 	intcall(0x10, &ireg, &oreg);
119 
120 	if (oreg.ax != 0x004f)
121 		return -1;
122 
123 	if ((vminfo.mode_attr & 0x15) == 0x05) {
124 		/* It's a supported text mode */
125 		is_graphic = 0;
126 #ifdef CONFIG_FB_BOOT_VESA_SUPPORT
127 	} else if ((vminfo.mode_attr & 0x99) == 0x99) {
128 		/* It's a graphics mode with linear frame buffer */
129 		is_graphic = 1;
130 		vesa_mode |= 0x4000; /* Request linear frame buffer */
131 #endif
132 	} else {
133 		return -1;	/* Invalid mode */
134 	}
135 
136 
137 	initregs(&ireg);
138 	ireg.ax = 0x4f02;
139 	ireg.bx = vesa_mode;
140 	intcall(0x10, &ireg, &oreg);
141 
142 	if (oreg.ax != 0x004f)
143 		return -1;
144 
145 	graphic_mode = is_graphic;
146 	if (!is_graphic) {
147 		/* Text mode */
148 		force_x = mode->x;
149 		force_y = mode->y;
150 		do_restore = 1;
151 	} else {
152 		/* Graphics mode */
153 		vesa_store_mode_params_graphics();
154 	}
155 
156 	return 0;
157 }
158 
159 
160 #ifndef _WAKEUP
161 
162 /* Switch DAC to 8-bit mode */
163 static void vesa_dac_set_8bits(void)
164 {
165 	struct biosregs ireg, oreg;
166 	u8 dac_size = 6;
167 
168 	/* If possible, switch the DAC to 8-bit mode */
169 	if (vginfo.capabilities & 1) {
170 		initregs(&ireg);
171 		ireg.ax = 0x4f08;
172 		ireg.bh = 0x08;
173 		intcall(0x10, &ireg, &oreg);
174 		if (oreg.ax == 0x004f)
175 			dac_size = oreg.bh;
176 	}
177 
178 	/* Set the color sizes to the DAC size, and offsets to 0 */
179 	boot_params.screen_info.red_size   = dac_size;
180 	boot_params.screen_info.green_size = dac_size;
181 	boot_params.screen_info.blue_size  = dac_size;
182 	boot_params.screen_info.rsvd_size  = dac_size;
183 
184 	boot_params.screen_info.red_pos    = 0;
185 	boot_params.screen_info.green_pos  = 0;
186 	boot_params.screen_info.blue_pos   = 0;
187 	boot_params.screen_info.rsvd_pos   = 0;
188 }
189 
190 /* Save the VESA protected mode info */
191 static void vesa_store_pm_info(void)
192 {
193 	struct biosregs ireg, oreg;
194 
195 	initregs(&ireg);
196 	ireg.ax = 0x4f0a;
197 	intcall(0x10, &ireg, &oreg);
198 
199 	if (oreg.ax != 0x004f)
200 		return;
201 
202 	boot_params.screen_info.vesapm_seg = oreg.es;
203 	boot_params.screen_info.vesapm_off = oreg.di;
204 }
205 
206 /*
207  * Save video mode parameters for graphics mode
208  */
209 static void vesa_store_mode_params_graphics(void)
210 {
211 	/* Tell the kernel we're in VESA graphics mode */
212 	boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
213 
214 	/* Mode parameters */
215 	boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
216 	boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
217 	boot_params.screen_info.lfb_width = vminfo.h_res;
218 	boot_params.screen_info.lfb_height = vminfo.v_res;
219 	boot_params.screen_info.lfb_depth = vminfo.bpp;
220 	boot_params.screen_info.pages = vminfo.image_planes;
221 	boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
222 	memcpy(&boot_params.screen_info.red_size,
223 	       &vminfo.rmask, 8);
224 
225 	/* General parameters */
226 	boot_params.screen_info.lfb_size = vginfo.total_memory;
227 
228 	if (vminfo.bpp <= 8)
229 		vesa_dac_set_8bits();
230 
231 	vesa_store_pm_info();
232 }
233 
234 /*
235  * Save EDID information for the kernel; this is invoked, separately,
236  * after mode-setting.
237  */
238 void vesa_store_edid(void)
239 {
240 #ifdef CONFIG_FIRMWARE_EDID
241 	struct biosregs ireg, oreg;
242 
243 	/* Apparently used as a nonsense token... */
244 	memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
245 
246 	if (vginfo.version < 0x0200)
247 		return;		/* EDID requires VBE 2.0+ */
248 
249 	initregs(&ireg);
250 	ireg.ax = 0x4f15;		/* VBE DDC */
251 	/* ireg.bx = 0x0000; */		/* Report DDC capabilities */
252 	/* ireg.cx = 0;	*/		/* Controller 0 */
253 	ireg.es = 0;			/* ES:DI must be 0 by spec */
254 	intcall(0x10, &ireg, &oreg);
255 
256 	if (oreg.ax != 0x004f)
257 		return;		/* No EDID */
258 
259 	/* BH = time in seconds to transfer EDD information */
260 	/* BL = DDC level supported */
261 
262 	ireg.ax = 0x4f15;		/* VBE DDC */
263 	ireg.bx = 0x0001;		/* Read EDID */
264 	/* ireg.cx = 0; */		/* Controller 0 */
265 	/* ireg.dx = 0;	*/		/* EDID block number */
266 	ireg.es = ds();
267 	ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
268 	intcall(0x10, &ireg, &oreg);
269 #endif /* CONFIG_FIRMWARE_EDID */
270 }
271 
272 #endif /* not _WAKEUP */
273 
274 static __videocard video_vesa =
275 {
276 	.card_name	= "VESA",
277 	.probe		= vesa_probe,
278 	.set_mode	= vesa_set_mode,
279 	.xmode_first	= VIDEO_FIRST_VESA,
280 	.xmode_n	= 0x200,
281 };
282