1/* ----------------------------------------------------------------------- *
2 *
3 *   Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
4 *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
5 *
6 *   Permission is hereby granted, free of charge, to any person
7 *   obtaining a copy of this software and associated documentation
8 *   files (the "Software"), to deal in the Software without
9 *   restriction, including without limitation the rights to use,
10 *   copy, modify, merge, publish, distribute, sublicense, and/or
11 *   sell copies of the Software, and to permit persons to whom
12 *   the Software is furnished to do so, subject to the following
13 *   conditions:
14 *
15 *   The above copyright notice and this permission notice shall
16 *   be included in all copies or substantial portions of the Software.
17 *
18 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 *   OTHER DEALINGS IN THE SOFTWARE.
26 *
27 * ----------------------------------------------------------------------- */
28
29/*
30 * initvesa.c
31 *
32 * Query the VESA BIOS and select a 640x480x32 mode with local mapping
33 * support, if one exists.
34 */
35
36#include <inttypes.h>
37#include <com32.h>
38#include <stdlib.h>
39#include <string.h>
40#include <limits.h>
41#include <graphics.h>
42
43#include "vesa.h"
44#include "mboot.h"
45
46struct vesa_info vesa_info;
47
48void set_graphics_mode(const struct multiboot_header *mbh,
49		       struct multiboot_info *mbi)
50{
51    com32sys_t rm;
52    uint16_t mode, bestmode, *mode_ptr;
53    struct vesa_general_info *gi;
54    struct vesa_mode_info *mi;
55    int pxf, bestpxf;
56    int wantx, wanty;
57    int err, besterr;
58    bool better;
59    addr_t viaddr;
60
61    /* Only do this if requested by the OS image */
62    if (!(mbh->flags & MULTIBOOT_VIDEO_MODE) || mbh->mode_type != 0)
63	return;
64
65    gi = lmalloc(sizeof *gi);
66    if (!gi)
67	return;
68
69    mi = lmalloc(sizeof *mi);
70    if (!mi)
71	goto out;
72
73    memset(&rm, 0, sizeof rm);
74    memset(gi, 0, sizeof *gi);
75
76    gi->signature = VBE2_MAGIC;	/* Get VBE2 extended data */
77    rm.eax.w[0] = 0x4F00;	/* Get SVGA general information */
78    rm.edi.w[0] = OFFS(gi);
79    rm.es = SEG(gi);
80    __intcall(0x10, &rm, &rm);
81
82    if (rm.eax.w[0] != 0x004F)
83	goto out;		/* Function call failed */
84    if (gi->signature != VESA_MAGIC)
85	goto out;		/* No magic */
86    if (gi->version < 0x0102)
87	goto out;		/* VESA 1.2+ required */
88
89    memcpy(&vesa_info.gi, gi, sizeof *gi);
90
91    /* Search for a suitable mode with a suitable color and memory model... */
92
93    mode_ptr = GET_PTR(gi->video_mode_ptr);
94    bestmode = 0;
95    bestpxf = 0;
96    wantx = mbh->width  ? mbh->width  : 0xffff;
97    wanty = mbh->height ? mbh->height : 0xffff;
98    besterr = wantx + wanty;
99
100    while ((mode = *mode_ptr++) != 0xFFFF) {
101	mode &= 0x1FF;		/* The rest are attributes of sorts */
102
103        memset(&rm, 0, sizeof rm);
104	memset(mi, 0, sizeof *mi);
105	rm.eax.w[0] = 0x4F01;	/* Get SVGA mode information */
106	rm.ecx.w[0] = mode;
107	rm.edi.w[0] = OFFS(mi);
108	rm.es = SEG(mi);
109	__intcall(0x10, &rm, &rm);
110
111	/* Must be a supported mode */
112	if (rm.eax.w[0] != 0x004f)
113	    continue;
114
115	/* Must be an LFB color graphics mode supported by the hardware.
116
117	   The bits tested are:
118	   7 - linear frame buffer
119	   4 - graphics mode
120	   3 - color mode
121	   1 - mode information available (mandatory in VBE 1.2+)
122	   0 - mode supported by hardware
123	 */
124	if ((mi->mode_attr & 0x009b) != 0x009b)
125	    continue;
126
127	/* We don't support multibank (interlaced memory) modes */
128	/*
129	 *  Note: The Bochs VESA BIOS (vbe.c 1.58 2006/08/19) violates the
130	 * specification which states that banks == 1 for unbanked modes;
131	 * fortunately it does report bank_size == 0 for those.
132	 */
133	if (mi->banks > 1 && mi->bank_size)
134	    continue;
135
136	/* Must either be a packed-pixel mode or a direct color mode
137	   (depending on VESA version ); must be a supported pixel format */
138
139	if (mi->bpp == 32 &&
140	    (mi->memory_layout == 4 ||
141	     (mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
142	      mi->bpos == 0)))
143	    pxf = 32;
144	else if (mi->bpp == 24 &&
145		 (mi->memory_layout == 4 ||
146		  (mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
147		   mi->bpos == 0)))
148	    pxf = 24;
149	else if (mi->bpp == 16 &&
150		 (mi->memory_layout == 4 ||
151		  (mi->memory_layout == 6 && mi->rpos == 11 && mi->gpos == 5 &&
152		   mi->bpos == 0)))
153	    pxf = 16;
154	else if (mi->bpp == 15 &&
155		 (mi->memory_layout == 4 ||
156		  (mi->memory_layout == 6 && mi->rpos == 10 && mi->gpos == 5 &&
157		   mi->bpos == 0)))
158	    pxf = 15;
159	else
160	    continue;
161
162	better = false;
163	err = abs(mi->h_res - wantx) + abs(mi->v_res - wanty);
164
165#define IS_GOOD(mi, bestx, besty) \
166	((mi)->h_res >= (bestx) && (mi)->v_res >= (besty))
167
168	if (!bestpxf)
169	    better = true;
170	else if (!IS_GOOD(&vesa_info.mi, wantx, wanty) &&
171		 IS_GOOD(mi, wantx, wanty))
172	    /* This matches criteria, which the previous one didn't */
173	    better = true;
174	else if (IS_GOOD(&vesa_info.mi, wantx, wanty) &&
175		 !IS_GOOD(mi, wantx, wanty))
176	    /* This doesn't match criteria, and the previous one did */
177	    better = false;
178	else if (err < besterr)
179	    better = true;
180	else if (err == besterr && (pxf == (int)mbh->depth || pxf > bestpxf))
181	    better = true;
182
183	if (better) {
184	    bestmode = mode;
185	    bestpxf = pxf;
186	    memcpy(&vesa_info.mi, mi, sizeof *mi);
187	}
188    }
189
190    if (!bestpxf)
191	goto out;		/* No mode found */
192
193    mi = &vesa_info.mi;
194    mode = bestmode;
195
196    /* Now set video mode */
197    memset(&rm, 0, sizeof rm);
198    rm.eax.w[0] = 0x4F02;	/* Set SVGA video mode */
199    mode |= 0x4000;		/* Request linear framebuffer */
200    rm.ebx.w[0] = mode;
201    __intcall(0x10, &rm, &rm);
202    if (rm.eax.w[0] != 0x004F)
203	goto out;		/* Failed to set mode */
204
205    mbi->flags |= MB_INFO_VIDEO_INFO;
206    mbi->vbe_mode = mode;
207    viaddr = map_data(&vesa_info, sizeof vesa_info, 4, 0);
208    mbi->vbe_control_info = viaddr + offsetof(struct vesa_info, gi);
209    mbi->vbe_mode_info = viaddr + offsetof(struct vesa_info, mi);
210
211    /* Get the VBE 2.x PM entry point if supported */
212    rm.eax.w[0] = 0x4F0A;
213    rm.ebx.w[0] = 0;
214    __intcall(0x10, &rm, &rm);
215    if (rm.eax.w[0] == 0x004F) {
216	mbi->vbe_interface_seg = rm.es;
217	mbi->vbe_interface_off = rm.edi.w[0];
218	mbi->vbe_interface_len = rm.ecx.w[0];
219    }
220
221    /* In theory this should be:
222     *
223     * UsingVga = (mi->mode_attr & 4) ? 0x0007 : 0x000f;
224     *
225     * However, that would assume all systems that claim to handle text
226     * output in VESA modes actually do that...
227     */
228    graphics_using_vga(0x0F, vesa_info.mi.h_res, vesa_info.mi.v_res);
229
230out:
231    lfree(mi);
232    lfree(gi);
233}
234