linux/arch/x86/boot/video-vesa.c
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   1/* -*- linux-c -*- ------------------------------------------------------- *
   2 *
   3 *   Copyright (C) 1991, 1992 Linus Torvalds
   4 *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5 *
   6 *   This file is part of the Linux kernel, and is made available under
   7 *   the terms of the GNU General Public License version 2.
   8 *
   9 * ----------------------------------------------------------------------- */
  10
  11/*
  12 * VESA text modes
  13 */
  14
  15#include "boot.h"
  16#include "video.h"
  17#include "vesa.h"
  18
  19/* VESA information */
  20static struct vesa_general_info vginfo;
  21static struct vesa_mode_info vminfo;
  22
  23static __videocard video_vesa;
  24
  25#ifndef _WAKEUP
  26static void vesa_store_mode_params_graphics(void);
  27#else /* _WAKEUP */
  28static inline void vesa_store_mode_params_graphics(void) {}
  29#endif /* _WAKEUP */
  30
  31static int vesa_probe(void)
  32{
  33#if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID)
  34        u16 ax, cx, di;
  35        u16 mode;
  36        addr_t mode_ptr;
  37        struct mode_info *mi;
  38        int nmodes = 0;
  39
  40        video_vesa.modes = GET_HEAP(struct mode_info, 0);
  41
  42        ax = 0x4f00;
  43        di = (size_t)&vginfo;
  44        asm(INT10
  45            : "+a" (ax), "+D" (di), "=m" (vginfo)
  46            : : "ebx", "ecx", "edx", "esi");
  47
  48        if (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                ax = 0x4f01;
  69                cx = mode;
  70                di = (size_t)&vminfo;
  71                asm(INT10
  72                    : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
  73                    : : "ebx", "edx", "esi");
  74
  75                if (ax != 0x004f)
  76                        continue;
  77
  78                if ((vminfo.mode_attr & 0x15) == 0x05) {
  79                        /* Text Mode, TTY BIOS supported,
  80                           supported by hardware */
  81                        mi = GET_HEAP(struct mode_info, 1);
  82                        mi->mode  = mode + VIDEO_FIRST_VESA;
  83                        mi->depth = 0; /* text */
  84                        mi->x     = vminfo.h_res;
  85                        mi->y     = vminfo.v_res;
  86                        nmodes++;
  87                } else if ((vminfo.mode_attr & 0x99) == 0x99 &&
  88                           (vminfo.memory_layout == 4 ||
  89                            vminfo.memory_layout == 6) &&
  90                           vminfo.memory_planes == 1) {
  91#ifdef CONFIG_FB_BOOT_VESA_SUPPORT
  92                        /* Graphics mode, color, linear frame buffer
  93                           supported.  Only register the mode if
  94                           if framebuffer is configured, however,
  95                           otherwise the user will be left without a screen. */
  96                        mi = GET_HEAP(struct mode_info, 1);
  97                        mi->mode = mode + VIDEO_FIRST_VESA;
  98                        mi->depth = vminfo.bpp;
  99                        mi->x = vminfo.h_res;
 100                        mi->y = vminfo.v_res;
 101                        nmodes++;
 102#endif
 103                }
 104        }
 105
 106        return nmodes;
 107#else
 108        return 0;
 109#endif /* CONFIG_VIDEO_VESA */
 110}
 111
 112static int vesa_set_mode(struct mode_info *mode)
 113{
 114        u16 ax, bx, cx, di;
 115        int is_graphic;
 116        u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
 117
 118        memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
 119
 120        ax = 0x4f01;
 121        cx = vesa_mode;
 122        di = (size_t)&vminfo;
 123        asm(INT10
 124            : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
 125            : : "ebx", "edx", "esi");
 126
 127        if (ax != 0x004f)
 128                return -1;
 129
 130        if ((vminfo.mode_attr & 0x15) == 0x05) {
 131                /* It's a supported text mode */
 132                is_graphic = 0;
 133#ifdef CONFIG_FB_BOOT_VESA_SUPPORT
 134        } else if ((vminfo.mode_attr & 0x99) == 0x99) {
 135                /* It's a graphics mode with linear frame buffer */
 136                is_graphic = 1;
 137                vesa_mode |= 0x4000; /* Request linear frame buffer */
 138#endif
 139        } else {
 140                return -1;      /* Invalid mode */
 141        }
 142
 143
 144        ax = 0x4f02;
 145        bx = vesa_mode;
 146        di = 0;
 147        asm volatile(INT10
 148                     : "+a" (ax), "+b" (bx), "+D" (di)
 149                     : : "ecx", "edx", "esi");
 150
 151        if (ax != 0x004f)
 152                return -1;
 153
 154        graphic_mode = is_graphic;
 155        if (!is_graphic) {
 156                /* Text mode */
 157                force_x = mode->x;
 158                force_y = mode->y;
 159                do_restore = 1;
 160        } else {
 161                /* Graphics mode */
 162                vesa_store_mode_params_graphics();
 163        }
 164
 165        return 0;
 166}
 167
 168
 169#ifndef _WAKEUP
 170
 171/* Switch DAC to 8-bit mode */
 172static void vesa_dac_set_8bits(void)
 173{
 174        u8 dac_size = 6;
 175
 176        /* If possible, switch the DAC to 8-bit mode */
 177        if (vginfo.capabilities & 1) {
 178                u16 ax, bx;
 179
 180                ax = 0x4f08;
 181                bx = 0x0800;
 182                asm volatile(INT10
 183                             : "+a" (ax), "+b" (bx)
 184                             : : "ecx", "edx", "esi", "edi");
 185
 186                if (ax == 0x004f)
 187                        dac_size = bx >> 8;
 188        }
 189
 190        /* Set the color sizes to the DAC size, and offsets to 0 */
 191        boot_params.screen_info.red_size = dac_size;
 192        boot_params.screen_info.green_size = dac_size;
 193        boot_params.screen_info.blue_size = dac_size;
 194        boot_params.screen_info.rsvd_size = dac_size;
 195
 196        boot_params.screen_info.red_pos = 0;
 197        boot_params.screen_info.green_pos = 0;
 198        boot_params.screen_info.blue_pos = 0;
 199        boot_params.screen_info.rsvd_pos = 0;
 200}
 201
 202/* Save the VESA protected mode info */
 203static void vesa_store_pm_info(void)
 204{
 205        u16 ax, bx, di, es;
 206
 207        ax = 0x4f0a;
 208        bx = di = 0;
 209        asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es"
 210            : "=d" (es), "+a" (ax), "+b" (bx), "+D" (di)
 211            : : "ecx", "esi");
 212
 213        if (ax != 0x004f)
 214                return;
 215
 216        boot_params.screen_info.vesapm_seg = es;
 217        boot_params.screen_info.vesapm_off = di;
 218}
 219
 220/*
 221 * Save video mode parameters for graphics mode
 222 */
 223static void vesa_store_mode_params_graphics(void)
 224{
 225        /* Tell the kernel we're in VESA graphics mode */
 226        boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
 227
 228        /* Mode parameters */
 229        boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
 230        boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
 231        boot_params.screen_info.lfb_width = vminfo.h_res;
 232        boot_params.screen_info.lfb_height = vminfo.v_res;
 233        boot_params.screen_info.lfb_depth = vminfo.bpp;
 234        boot_params.screen_info.pages = vminfo.image_planes;
 235        boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
 236        memcpy(&boot_params.screen_info.red_size,
 237               &vminfo.rmask, 8);
 238
 239        /* General parameters */
 240        boot_params.screen_info.lfb_size = vginfo.total_memory;
 241
 242        if (vminfo.bpp <= 8)
 243                vesa_dac_set_8bits();
 244
 245        vesa_store_pm_info();
 246}
 247
 248/*
 249 * Save EDID information for the kernel; this is invoked, separately,
 250 * after mode-setting.
 251 */
 252void vesa_store_edid(void)
 253{
 254#ifdef CONFIG_FIRMWARE_EDID
 255        u16 ax, bx, cx, dx, di;
 256
 257        /* Apparently used as a nonsense token... */
 258        memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
 259
 260        if (vginfo.version < 0x0200)
 261                return;         /* EDID requires VBE 2.0+ */
 262
 263        ax = 0x4f15;            /* VBE DDC */
 264        bx = 0x0000;            /* Report DDC capabilities */
 265        cx = 0;                 /* Controller 0 */
 266        di = 0;                 /* ES:DI must be 0 by spec */
 267
 268        /* Note: The VBE DDC spec is different from the main VESA spec;
 269           we genuinely have to assume all registers are destroyed here. */
 270
 271        asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es"
 272            : "+a" (ax), "+b" (bx)
 273            :  "c" (cx), "D" (di)
 274            : "esi");
 275
 276        if (ax != 0x004f)
 277                return;         /* No EDID */
 278
 279        /* BH = time in seconds to transfer EDD information */
 280        /* BL = DDC level supported */
 281
 282        ax = 0x4f15;            /* VBE DDC */
 283        bx = 0x0001;            /* Read EDID */
 284        cx = 0;                 /* Controller 0 */
 285        dx = 0;                 /* EDID block number */
 286        di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */
 287        asm(INT10
 288            : "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info)
 289            : "c" (cx), "D" (di)
 290            : "esi");
 291#endif /* CONFIG_FIRMWARE_EDID */
 292}
 293
 294#endif /* not _WAKEUP */
 295
 296static __videocard video_vesa =
 297{
 298        .card_name      = "VESA",
 299        .probe          = vesa_probe,
 300        .set_mode       = vesa_set_mode,
 301        .xmode_first    = VIDEO_FIRST_VESA,
 302        .xmode_n        = 0x200,
 303};
 304