LXR linux/arch/x86/boot/video-vesa.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/* -*- linux-c -*- ------------------------------------------------------- *
   3 *
   4 *   Copyright (C) 1991, 1992 Linus Torvalds
   5 *   Copyright 2007 rPath, Inc. - All Rights Reserved
   6 *   Copyright 2009 Intel Corporation; author H. Peter Anvin
   7 *
   8 * ----------------------------------------------------------------------- */
   9
  10/*
  11 * VESA text modes
  12 */
  13
  14#include "boot.h"
  15#include "video.h"
  16#include "vesa.h"
  17#include "string.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        struct biosregs ireg, oreg;
  34        u16 mode;
  35        addr_t mode_ptr;
  36        struct mode_info *mi;
  37        int nmodes = 0;
  38
  39        video_vesa.modes = GET_HEAP(struct mode_info, 0);
  40
  41        initregs(&ireg);
  42        ireg.ax = 0x4f00;
  43        ireg.di = (size_t)&vginfo;
  44        intcall(0x10, &ireg, &oreg);
  45
  46        if (oreg.ax != 0x004f ||
  47            vginfo.signature != VESA_MAGIC ||
  48            vginfo.version < 0x0102)
  49                return 0;       /* Not present */
  50
  51        set_fs(vginfo.video_mode_ptr.seg);
  52        mode_ptr = vginfo.video_mode_ptr.off;
  53
  54        while ((mode = rdfs16(mode_ptr)) != 0xffff) {
  55                mode_ptr += 2;
  56
  57                if (!heap_free(sizeof(struct mode_info)))
  58                        break;  /* Heap full, can't save mode info */
  59
  60                if (mode & ~0x1ff)
  61                        continue;
  62
  63                memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */
  64
  65                ireg.ax = 0x4f01;
  66                ireg.cx = mode;
  67                ireg.di = (size_t)&vminfo;
  68                intcall(0x10, &ireg, &oreg);
  69
  70                if (oreg.ax != 0x004f)
  71                        continue;
  72
  73                if ((vminfo.mode_attr & 0x15) == 0x05) {
  74                        /* Text Mode, TTY BIOS supported,
  75                           supported by hardware */
  76                        mi = GET_HEAP(struct mode_info, 1);
  77                        mi->mode  = mode + VIDEO_FIRST_VESA;
  78                        mi->depth = 0; /* text */
  79                        mi->x     = vminfo.h_res;
  80                        mi->y     = vminfo.v_res;
  81                        nmodes++;
  82                } else if ((vminfo.mode_attr & 0x99) == 0x99 &&
  83                           (vminfo.memory_layout == 4 ||
  84                            vminfo.memory_layout == 6) &&
  85                           vminfo.memory_planes == 1) {
  86#ifdef CONFIG_FB_BOOT_VESA_SUPPORT
  87                        /* Graphics mode, color, linear frame buffer
  88                           supported.  Only register the mode if
  89                           if framebuffer is configured, however,
  90                           otherwise the user will be left without a screen. */
  91                        mi = GET_HEAP(struct mode_info, 1);
  92                        mi->mode = mode + VIDEO_FIRST_VESA;
  93                        mi->depth = vminfo.bpp;
  94                        mi->x = vminfo.h_res;
  95                        mi->y = vminfo.v_res;
  96                        nmodes++;
  97#endif
  98                }
  99        }
 100
 101        return nmodes;
 102}
 103
 104static int vesa_set_mode(struct mode_info *mode)
 105{
 106        struct biosregs ireg, oreg;
 107        int is_graphic;
 108        u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
 109
 110        memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */
 111
 112        initregs(&ireg);
 113        ireg.ax = 0x4f01;
 114        ireg.cx = vesa_mode;
 115        ireg.di = (size_t)&vminfo;
 116        intcall(0x10, &ireg, &oreg);
 117
 118        if (oreg.ax != 0x004f)
 119                return -1;
 120
 121        if ((vminfo.mode_attr & 0x15) == 0x05) {
 122                /* It's a supported text mode */
 123                is_graphic = 0;
 124#ifdef CONFIG_FB_BOOT_VESA_SUPPORT
 125        } else if ((vminfo.mode_attr & 0x99) == 0x99) {
 126                /* It's a graphics mode with linear frame buffer */
 127                is_graphic = 1;
 128                vesa_mode |= 0x4000; /* Request linear frame buffer */
 129#endif
 130        } else {
 131                return -1;      /* Invalid mode */
 132        }
 133
 134
 135        initregs(&ireg);
 136        ireg.ax = 0x4f02;
 137        ireg.bx = vesa_mode;
 138        intcall(0x10, &ireg, &oreg);
 139
 140        if (oreg.ax != 0x004f)
 141                return -1;
 142
 143        graphic_mode = is_graphic;
 144        if (!is_graphic) {
 145                /* Text mode */
 146                force_x = mode->x;
 147                force_y = mode->y;
 148                do_restore = 1;
 149        } else {
 150                /* Graphics mode */
 151                vesa_store_mode_params_graphics();
 152        }
 153
 154        return 0;
 155}
 156
 157
 158#ifndef _WAKEUP
 159
 160/* Switch DAC to 8-bit mode */
 161static void vesa_dac_set_8bits(void)
 162{
 163        struct biosregs ireg, oreg;
 164        u8 dac_size = 6;
 165
 166        /* If possible, switch the DAC to 8-bit mode */
 167        if (vginfo.capabilities & 1) {
 168                initregs(&ireg);
 169                ireg.ax = 0x4f08;
 170                ireg.bh = 0x08;
 171                intcall(0x10, &ireg, &oreg);
 172                if (oreg.ax == 0x004f)
 173                        dac_size = oreg.bh;
 174        }
 175
 176        /* Set the color sizes to the DAC size, and offsets to 0 */
 177        boot_params.screen_info.red_size   = dac_size;
 178        boot_params.screen_info.green_size = dac_size;
 179        boot_params.screen_info.blue_size  = dac_size;
 180        boot_params.screen_info.rsvd_size  = dac_size;
 181
 182        boot_params.screen_info.red_pos    = 0;
 183        boot_params.screen_info.green_pos  = 0;
 184        boot_params.screen_info.blue_pos   = 0;
 185        boot_params.screen_info.rsvd_pos   = 0;
 186}
 187
 188/* Save the VESA protected mode info */
 189static void vesa_store_pm_info(void)
 190{
 191        struct biosregs ireg, oreg;
 192
 193        initregs(&ireg);
 194        ireg.ax = 0x4f0a;
 195        intcall(0x10, &ireg, &oreg);
 196
 197        if (oreg.ax != 0x004f)
 198                return;
 199
 200        boot_params.screen_info.vesapm_seg = oreg.es;
 201        boot_params.screen_info.vesapm_off = oreg.di;
 202}
 203
 204/*
 205 * Save video mode parameters for graphics mode
 206 */
 207static void vesa_store_mode_params_graphics(void)
 208{
 209        /* Tell the kernel we're in VESA graphics mode */
 210        boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
 211
 212        /* Mode parameters */
 213        boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
 214        boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
 215        boot_params.screen_info.lfb_width = vminfo.h_res;
 216        boot_params.screen_info.lfb_height = vminfo.v_res;
 217        boot_params.screen_info.lfb_depth = vminfo.bpp;
 218        boot_params.screen_info.pages = vminfo.image_planes;
 219        boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
 220        memcpy(&boot_params.screen_info.red_size,
 221               &vminfo.rmask, 8);
 222
 223        /* General parameters */
 224        boot_params.screen_info.lfb_size = vginfo.total_memory;
 225
 226        if (vminfo.bpp <= 8)
 227                vesa_dac_set_8bits();
 228
 229        vesa_store_pm_info();
 230}
 231
 232/*
 233 * Save EDID information for the kernel; this is invoked, separately,
 234 * after mode-setting.
 235 */
 236void vesa_store_edid(void)
 237{
 238#ifdef CONFIG_FIRMWARE_EDID
 239        struct biosregs ireg, oreg;
 240
 241        /* Apparently used as a nonsense token... */
 242        memset(&boot_params.edid_info, 0x13, sizeof(boot_params.edid_info));
 243
 244        if (vginfo.version < 0x0200)
 245                return;         /* EDID requires VBE 2.0+ */
 246
 247        initregs(&ireg);
 248        ireg.ax = 0x4f15;               /* VBE DDC */
 249        /* ireg.bx = 0x0000; */         /* Report DDC capabilities */
 250        /* ireg.cx = 0; */              /* Controller 0 */
 251        ireg.es = 0;                    /* ES:DI must be 0 by spec */
 252        intcall(0x10, &ireg, &oreg);
 253
 254        if (oreg.ax != 0x004f)
 255                return;         /* No EDID */
 256
 257        /* BH = time in seconds to transfer EDD information */
 258        /* BL = DDC level supported */
 259
 260        ireg.ax = 0x4f15;               /* VBE DDC */
 261        ireg.bx = 0x0001;               /* Read EDID */
 262        /* ireg.cx = 0; */              /* Controller 0 */
 263        /* ireg.dx = 0; */              /* EDID block number */
 264        ireg.es = ds();
 265        ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
 266        intcall(0x10, &ireg, &oreg);
 267#endif /* CONFIG_FIRMWARE_EDID */
 268}
 269
 270#endif /* not _WAKEUP */
 271
 272static __videocard video_vesa =
 273{
 274        .card_name      = "VESA",
 275        .probe          = vesa_probe,
 276        .set_mode       = vesa_set_mode,
 277        .xmode_first    = VIDEO_FIRST_VESA,
 278        .xmode_n        = 0x200,
 279};
 280