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   1 /*
   2  *  linux/drivers/video/vgacon.c -- Low level VGA based console driver
   3  *
   4  *      Created 28 Sep 1997 by Geert Uytterhoeven
   5  *
   6  *      Rewritten by Martin Mares <mj@ucw.cz>, July 1998
   7  *
   8  *  This file is based on the old console.c, vga.c and vesa_blank.c drivers.
   9  *
  10  *      Copyright (C) 1991, 1992  Linus Torvalds
  11  *                          1995  Jay Estabrook
  12  *
  13  *      User definable mapping table and font loading by Eugene G. Crosser,
  14  *      <crosser@average.org>
  15  *
  16  *      Improved loadable font/UTF-8 support by H. Peter Anvin
  17  *      Feb-Sep 1995 <peter.anvin@linux.org>
  18  *
  19  *      Colour palette handling, by Simon Tatham
  20  *      17-Jun-95 <sgt20@cam.ac.uk>
  21  *
  22  *      if 512 char mode is already enabled don't re-enable it,
  23  *      because it causes screen to flicker, by Mitja Horvat
  24  *      5-May-96 <mitja.horvat@guest.arnes.si>
  25  *
  26  *      Use 2 outw instead of 4 outb_p to reduce erroneous text
  27  *      flashing on RHS of screen during heavy console scrolling .
  28  *      Oct 1996, Paul Gortmaker.
  29  *
  30  *
  31  *  This file is subject to the terms and conditions of the GNU General Public
  32  *  License.  See the file COPYING in the main directory of this archive for
  33  *  more details.
  34  */
  35
  36 #include <linux/config.h>
  37 #include <linux/module.h>
  38 #include <linux/types.h>
  39 #include <linux/sched.h>
  40 #include <linux/fs.h>
  41 #include <linux/kernel.h>
  42 #include <linux/tty.h>
  43 #include <linux/console.h>
  44 #include <linux/string.h>
  45 #include <linux/kd.h>
  46 #include <linux/slab.h>
  47 #include <linux/vt_kern.h>
  48 #include <linux/selection.h>
  49 #include <linux/spinlock.h>
  50 #include <linux/ioport.h>
  51 #include <linux/init.h>
  52 #include <linux/smp_lock.h>
  53 #include <video/vga.h>
  54 #include <asm/io.h>
  55
  56 static DEFINE_SPINLOCK(vga_lock);
  57 static int cursor_size_lastfrom;
  58 static int cursor_size_lastto;
  59 static struct vgastate state;
  60
  61 #define BLANK 0x0020
  62
  63 #define CAN_LOAD_EGA_FONTS      /* undefine if the user must not do this */
  64 #define CAN_LOAD_PALETTE        /* undefine if the user must not do this */
  65
  66 /* You really do _NOT_ want to define this, unless you have buggy
  67  * Trident VGA which will resize cursor when moving it between column
  68  * 15 & 16. If you define this and your VGA is OK, inverse bug will
  69  * appear.
  70  */
  71 #undef TRIDENT_GLITCH
  72
  73 /*
  74  *  Interface used by the world
  75  */
  76
  77 static const char *vgacon_startup(void);
  78 static void vgacon_init(struct vc_data *c, int init);
  79 static void vgacon_deinit(struct vc_data *c);
  80 static void vgacon_cursor(struct vc_data *c, int mode);
  81 static int vgacon_switch(struct vc_data *c);
  82 static int vgacon_blank(struct vc_data *c, int blank, int mode_switch);
  83 static int vgacon_set_palette(struct vc_data *vc, unsigned char *table);
  84 static int vgacon_scrolldelta(struct vc_data *c, int lines);
  85 static int vgacon_set_origin(struct vc_data *c);
  86 static void vgacon_save_screen(struct vc_data *c);
  87 static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,
  88                          int lines);
  89 static u8 vgacon_build_attr(struct vc_data *c, u8 color, u8 intensity,
  90                             u8 blink, u8 underline, u8 reverse);
  91 static void vgacon_invert_region(struct vc_data *c, u16 * p, int count);
  92 static unsigned long vgacon_uni_pagedir[2];
  93
  94
  95 /* Description of the hardware situation */
  96 static unsigned long    vga_vram_base;          /* Base of video memory */
  97 static unsigned long    vga_vram_end;           /* End of video memory */
  98 static int              vga_vram_size;          /* Size of video memory */
  99 static u16              vga_video_port_reg;     /* Video register select port */
 100 static u16              vga_video_port_val;     /* Video register value port */
 101 static unsigned int     vga_video_num_columns;  /* Number of text columns */
 102 static unsigned int     vga_video_num_lines;    /* Number of text lines */
 103 static int              vga_can_do_color = 0;   /* Do we support colors? */
 104 static unsigned int     vga_default_font_height;/* Height of default screen font */
 105 static unsigned char    vga_video_type;         /* Card type */
 106 static unsigned char    vga_hardscroll_enabled;
 107 static unsigned char    vga_hardscroll_user_enable = 1;
 108 static unsigned char    vga_font_is_default = 1;
 109 static int              vga_vesa_blanked;
 110 static int              vga_palette_blanked;
 111 static int              vga_is_gfx;
 112 static int              vga_512_chars;
 113 static int              vga_video_font_height;
 114 static int              vga_scan_lines;
 115 static unsigned int     vga_rolled_over = 0;
 116
 117 static int __init no_scroll(char *str)
 118 {
 119         /*
 120          * Disabling scrollback is required for the Braillex ib80-piezo
 121          * Braille reader made by F.H. Papenmeier (Germany).
 122          * Use the "no-scroll" bootflag.
 123          */
 124         vga_hardscroll_user_enable = vga_hardscroll_enabled = 0;
 125         return 1;
 126 }
 127
 128 __setup("no-scroll", no_scroll);
 129
 130 /*
 131  * By replacing the four outb_p with two back to back outw, we can reduce
 132  * the window of opportunity to see text mislocated to the RHS of the
 133  * console during heavy scrolling activity. However there is the remote
 134  * possibility that some pre-dinosaur hardware won't like the back to back
 135  * I/O. Since the Xservers get away with it, we should be able to as well.
 136  */
 137 static inline void write_vga(unsigned char reg, unsigned int val)
 138 {
 139         unsigned int v1, v2;
 140         unsigned long flags;
 141
 142         /*
 143          * ddprintk might set the console position from interrupt
 144          * handlers, thus the write has to be IRQ-atomic.
 145          */
 146         spin_lock_irqsave(&vga_lock, flags);
 147
 148 #ifndef SLOW_VGA
 149         v1 = reg + (val & 0xff00);
 150         v2 = reg + 1 + ((val << 8) & 0xff00);
 151         outw(v1, vga_video_port_reg);
 152         outw(v2, vga_video_port_reg);
 153 #else
 154         outb_p(reg, vga_video_port_reg);
 155         outb_p(val >> 8, vga_video_port_val);
 156         outb_p(reg + 1, vga_video_port_reg);
 157         outb_p(val & 0xff, vga_video_port_val);
 158 #endif
 159         spin_unlock_irqrestore(&vga_lock, flags);
 160 }
 161
 162 static const char __init *vgacon_startup(void)
 163 {
 164         const char *display_desc = NULL;
 165         u16 saved1, saved2;
 166         volatile u16 *p;
 167
 168         if (ORIG_VIDEO_ISVGA == VIDEO_TYPE_VLFB) {
 169               no_vga:
 170 #ifdef CONFIG_DUMMY_CONSOLE
 171                 conswitchp = &dummy_con;
 172                 return conswitchp->con_startup();
 173 #else
 174                 return NULL;
 175 #endif
 176         }
 177
 178         /* VGA16 modes are not handled by VGACON */
 179         if ((ORIG_VIDEO_MODE == 0x0D) ||        /* 320x200/4 */
 180             (ORIG_VIDEO_MODE == 0x0E) ||        /* 640x200/4 */
 181             (ORIG_VIDEO_MODE == 0x10) ||        /* 640x350/4 */
 182             (ORIG_VIDEO_MODE == 0x12) ||        /* 640x480/4 */
 183             (ORIG_VIDEO_MODE == 0x6A))  /* 800x600/4, 0x6A is very common */
 184                 goto no_vga;
 185
 186         vga_video_num_lines = ORIG_VIDEO_LINES;
 187         vga_video_num_columns = ORIG_VIDEO_COLS;
 188         state.vgabase = NULL;
 189
 190         if (ORIG_VIDEO_MODE == 7) {     /* Is this a monochrome display? */
 191                 vga_vram_base = 0xb0000;
 192                 vga_video_port_reg = VGA_CRT_IM;
 193                 vga_video_port_val = VGA_CRT_DM;
 194                 if ((ORIG_VIDEO_EGA_BX & 0xff) != 0x10) {
 195                         static struct resource ega_console_resource =
 196                             { "ega", 0x3B0, 0x3BF };
 197                         vga_video_type = VIDEO_TYPE_EGAM;
 198                         vga_vram_end = 0xb8000;
 199                         display_desc = "EGA+";
 200                         request_resource(&ioport_resource,
 201                                          &ega_console_resource);
 202                 } else {
 203                         static struct resource mda1_console_resource =
 204                             { "mda", 0x3B0, 0x3BB };
 205                         static struct resource mda2_console_resource =
 206                             { "mda", 0x3BF, 0x3BF };
 207                         vga_video_type = VIDEO_TYPE_MDA;
 208                         vga_vram_end = 0xb2000;
 209                         display_desc = "*MDA";
 210                         request_resource(&ioport_resource,
 211                                          &mda1_console_resource);
 212                         request_resource(&ioport_resource,
 213                                          &mda2_console_resource);
 214                         vga_video_font_height = 14;
 215                 }
 216         } else {
 217                 /* If not, it is color. */
 218                 vga_can_do_color = 1;
 219                 vga_vram_base = 0xb8000;
 220                 vga_video_port_reg = VGA_CRT_IC;
 221                 vga_video_port_val = VGA_CRT_DC;
 222                 if ((ORIG_VIDEO_EGA_BX & 0xff) != 0x10) {
 223                         int i;
 224
 225                         vga_vram_end = 0xc0000;
 226
 227                         if (!ORIG_VIDEO_ISVGA) {
 228                                 static struct resource ega_console_resource
 229                                     = { "ega", 0x3C0, 0x3DF };
 230                                 vga_video_type = VIDEO_TYPE_EGAC;
 231                                 display_desc = "EGA";
 232                                 request_resource(&ioport_resource,
 233                                                  &ega_console_resource);
 234                         } else {
 235                                 static struct resource vga_console_resource
 236                                     = { "vga+", 0x3C0, 0x3DF };
 237                                 vga_video_type = VIDEO_TYPE_VGAC;
 238                                 display_desc = "VGA+";
 239                                 request_resource(&ioport_resource,
 240                                                  &vga_console_resource);
 241
 242 #ifdef VGA_CAN_DO_64KB
 243                                 /*
 244                                  * get 64K rather than 32K of video RAM.
 245                                  * This doesn't actually work on all "VGA"
 246                                  * controllers (it seems like setting MM=01
 247                                  * and COE=1 isn't necessarily a good idea)
 248                                  */
 249                                 vga_vram_base = 0xa0000;
 250                                 vga_vram_end = 0xb0000;
 251                                 outb_p(6, VGA_GFX_I);
 252                                 outb_p(6, VGA_GFX_D);
 253 #endif
 254                                 /*
 255                                  * Normalise the palette registers, to point
 256                                  * the 16 screen colours to the first 16
 257                                  * DAC entries.
 258                                  */
 259
 260                                 for (i = 0; i < 16; i++) {
 261                                         inb_p(VGA_IS1_RC);
 262                                         outb_p(i, VGA_ATT_W);
 263                                         outb_p(i, VGA_ATT_W);
 264                                 }
 265                                 outb_p(0x20, VGA_ATT_W);
 266
 267                                 /*
 268                                  * Now set the DAC registers back to their
 269                                  * default values
 270                                  */
 271                                 for (i = 0; i < 16; i++) {
 272                                         outb_p(color_table[i], VGA_PEL_IW);
 273                                         outb_p(default_red[i], VGA_PEL_D);
 274                                         outb_p(default_grn[i], VGA_PEL_D);
 275                                         outb_p(default_blu[i], VGA_PEL_D);
 276                                 }
 277                         }
 278                 } else {
 279                         static struct resource cga_console_resource =
 280                             { "cga", 0x3D4, 0x3D5 };
 281                         vga_video_type = VIDEO_TYPE_CGA;
 282                         vga_vram_end = 0xba000;
 283                         display_desc = "*CGA";
 284                         request_resource(&ioport_resource,
 285                                          &cga_console_resource);
 286                         vga_video_font_height = 8;
 287                 }
 288         }
 289
 290         vga_vram_base = VGA_MAP_MEM(vga_vram_base);
 291         vga_vram_end = VGA_MAP_MEM(vga_vram_end);
 292         vga_vram_size = vga_vram_end - vga_vram_base;
 293
 294         /*
 295          *      Find out if there is a graphics card present.
 296          *      Are there smarter methods around?
 297          */
 298         p = (volatile u16 *) vga_vram_base;
 299         saved1 = scr_readw(p);
 300         saved2 = scr_readw(p + 1);
 301         scr_writew(0xAA55, p);
 302         scr_writew(0x55AA, p + 1);
 303         if (scr_readw(p) != 0xAA55 || scr_readw(p + 1) != 0x55AA) {
 304                 scr_writew(saved1, p);
 305                 scr_writew(saved2, p + 1);
 306                 goto no_vga;
 307         }
 308         scr_writew(0x55AA, p);
 309         scr_writew(0xAA55, p + 1);
 310         if (scr_readw(p) != 0x55AA || scr_readw(p + 1) != 0xAA55) {
 311                 scr_writew(saved1, p);
 312                 scr_writew(saved2, p + 1);
 313                 goto no_vga;
 314         }
 315         scr_writew(saved1, p);
 316         scr_writew(saved2, p + 1);
 317
 318         if (vga_video_type == VIDEO_TYPE_EGAC
 319             || vga_video_type == VIDEO_TYPE_VGAC
 320             || vga_video_type == VIDEO_TYPE_EGAM) {
 321                 vga_hardscroll_enabled = vga_hardscroll_user_enable;
 322                 vga_default_font_height = ORIG_VIDEO_POINTS;
 323                 vga_video_font_height = ORIG_VIDEO_POINTS;
 324                 /* This may be suboptimal but is a safe bet - go with it */
 325                 vga_scan_lines =
 326                     vga_video_font_height * vga_video_num_lines;
 327         }
 328         return display_desc;
 329 }
 330
 331 static void vgacon_init(struct vc_data *c, int init)
 332 {
 333         unsigned long p;
 334
 335         /* We cannot be loaded as a module, therefore init is always 1 */
 336         c->vc_can_do_color = vga_can_do_color;
 337         c->vc_cols = vga_video_num_columns;
 338         c->vc_rows = vga_video_num_lines;
 339         c->vc_scan_lines = vga_scan_lines;
 340         c->vc_font.height = vga_video_font_height;
 341         c->vc_complement_mask = 0x7700;
 342         if (vga_512_chars)
 343                 c->vc_hi_font_mask = 0x0800;
 344         p = *c->vc_uni_pagedir_loc;
 345         if (c->vc_uni_pagedir_loc == &c->vc_uni_pagedir ||
 346             !--c->vc_uni_pagedir_loc[1])
 347                 con_free_unimap(c);
 348         c->vc_uni_pagedir_loc = vgacon_uni_pagedir;
 349         vgacon_uni_pagedir[1]++;
 350         if (!vgacon_uni_pagedir[0] && p)
 351                 con_set_default_unimap(c);
 352 }
 353
 354 static inline void vga_set_mem_top(struct vc_data *c)
 355 {
 356         write_vga(12, (c->vc_visible_origin - vga_vram_base) / 2);
 357 }
 358
 359 static void vgacon_deinit(struct vc_data *c)
 360 {
 361         /* When closing the last console, reset video origin */
 362         if (!--vgacon_uni_pagedir[1]) {
 363                 c->vc_visible_origin = vga_vram_base;
 364                 vga_set_mem_top(c);
 365                 con_free_unimap(c);
 366         }
 367         c->vc_uni_pagedir_loc = &c->vc_uni_pagedir;
 368         con_set_default_unimap(c);
 369 }
 370
 371 static u8 vgacon_build_attr(struct vc_data *c, u8 color, u8 intensity,
 372                             u8 blink, u8 underline, u8 reverse)
 373 {
 374         u8 attr = color;
 375
 376         if (vga_can_do_color) {
 377                 if (underline)
 378                         attr = (attr & 0xf0) | c->vc_ulcolor;
 379                 else if (intensity == 0)
 380                         attr = (attr & 0xf0) | c->vc_halfcolor;
 381         }
 382         if (reverse)
 383                 attr =
 384                     ((attr) & 0x88) | ((((attr) >> 4) | ((attr) << 4)) &
 385                                        0x77);
 386         if (blink)
 387                 attr ^= 0x80;
 388         if (intensity == 2)
 389                 attr ^= 0x08;
 390         if (!vga_can_do_color) {
 391                 if (underline)
 392                         attr = (attr & 0xf8) | 0x01;
 393                 else if (intensity == 0)
 394                         attr = (attr & 0xf0) | 0x08;
 395         }
 396         return attr;
 397 }
 398
 399 static void vgacon_invert_region(struct vc_data *c, u16 * p, int count)
 400 {
 401         int col = vga_can_do_color;
 402
 403         while (count--) {
 404                 u16 a = scr_readw(p);
 405                 if (col)
 406                         a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) |
 407                             (((a) & 0x0700) << 4);
 408                 else
 409                         a ^= ((a & 0x0700) == 0x0100) ? 0x7000 : 0x7700;
 410                 scr_writew(a, p++);
 411         }
 412 }
 413
 414 static void vgacon_set_cursor_size(int xpos, int from, int to)
 415 {
 416         unsigned long flags;
 417         int curs, cure;
 418
 419 #ifdef TRIDENT_GLITCH
 420         if (xpos < 16)
 421                 from--, to--;
 422 #endif
 423
 424         if ((from == cursor_size_lastfrom) && (to == cursor_size_lastto))
 425                 return;
 426         cursor_size_lastfrom = from;
 427         cursor_size_lastto = to;
 428
 429         spin_lock_irqsave(&vga_lock, flags);
 430         outb_p(0x0a, vga_video_port_reg);       /* Cursor start */
 431         curs = inb_p(vga_video_port_val);
 432         outb_p(0x0b, vga_video_port_reg);       /* Cursor end */
 433         cure = inb_p(vga_video_port_val);
 434
 435         curs = (curs & 0xc0) | from;
 436         cure = (cure & 0xe0) | to;
 437
 438         outb_p(0x0a, vga_video_port_reg);       /* Cursor start */
 439         outb_p(curs, vga_video_port_val);
 440         outb_p(0x0b, vga_video_port_reg);       /* Cursor end */
 441         outb_p(cure, vga_video_port_val);
 442         spin_unlock_irqrestore(&vga_lock, flags);
 443 }
 444
 445 static void vgacon_cursor(struct vc_data *c, int mode)
 446 {
 447         if (c->vc_origin != c->vc_visible_origin)
 448                 vgacon_scrolldelta(c, 0);
 449         switch (mode) {
 450         case CM_ERASE:
 451                 write_vga(14, (vga_vram_end - vga_vram_base - 1) / 2);
 452                 break;
 453
 454         case CM_MOVE:
 455         case CM_DRAW:
 456                 write_vga(14, (c->vc_pos - vga_vram_base) / 2);
 457                 switch (c->vc_cursor_type & 0x0f) {
 458                 case CUR_UNDERLINE:
 459                         vgacon_set_cursor_size(c->vc_x,
 460                                                c->vc_font.height -
 461                                                (c->vc_font.height <
 462                                                 10 ? 2 : 3),
 463                                                c->vc_font.height -
 464                                                (c->vc_font.height <
 465                                                 10 ? 1 : 2));
 466                         break;
 467                 case CUR_TWO_THIRDS:
 468                         vgacon_set_cursor_size(c->vc_x,
 469                                                c->vc_font.height / 3,
 470                                                c->vc_font.height -
 471                                                (c->vc_font.height <
 472                                                 10 ? 1 : 2));
 473                         break;
 474                 case CUR_LOWER_THIRD:
 475                         vgacon_set_cursor_size(c->vc_x,
 476                                                (c->vc_font.height * 2) / 3,
 477                                                c->vc_font.height -
 478                                                (c->vc_font.height <
 479                                                 10 ? 1 : 2));
 480                         break;
 481                 case CUR_LOWER_HALF:
 482                         vgacon_set_cursor_size(c->vc_x,
 483                                                c->vc_font.height / 2,
 484                                                c->vc_font.height -
 485                                                (c->vc_font.height <
 486                                                 10 ? 1 : 2));
 487                         break;
 488                 case CUR_NONE:
 489                         vgacon_set_cursor_size(c->vc_x, 31, 30);
 490                         break;
 491                 default:
 492                         vgacon_set_cursor_size(c->vc_x, 1,
 493                                                c->vc_font.height);
 494                         break;
 495                 }
 496                 break;
 497         }
 498 }
 499
 500 static int vgacon_doresize(struct vc_data *c,
 501                 unsigned int width, unsigned int height)
 502 {
 503         unsigned long flags;
 504         unsigned int scanlines = height * c->vc_font.height;
 505         u8 scanlines_lo, r7, vsync_end, mode;
 506
 507         spin_lock_irqsave(&vga_lock, flags);
 508
 509         outb_p(VGA_CRTC_MODE, vga_video_port_reg);
 510         mode = inb_p(vga_video_port_val);
 511
 512         if (mode & 0x04)
 513                 scanlines >>= 1;
 514
 515         scanlines -= 1;
 516         scanlines_lo = scanlines & 0xff;
 517
 518         outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
 519         r7 = inb_p(vga_video_port_val) & ~0x42;
 520
 521         if (scanlines & 0x100)
 522                 r7 |= 0x02;
 523         if (scanlines & 0x200)
 524                 r7 |= 0x40;
 525
 526         /* deprotect registers */
 527         outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
 528         vsync_end = inb_p(vga_video_port_val);
 529         outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
 530         outb_p(vsync_end & ~0x80, vga_video_port_val);
 531
 532         outb_p(VGA_CRTC_H_DISP, vga_video_port_reg);
 533         outb_p(width - 1, vga_video_port_val);
 534         outb_p(VGA_CRTC_OFFSET, vga_video_port_reg);
 535         outb_p(width >> 1, vga_video_port_val);
 536
 537         outb_p(VGA_CRTC_V_DISP_END, vga_video_port_reg);
 538         outb_p(scanlines_lo, vga_video_port_val);
 539         outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
 540         outb_p(r7,vga_video_port_val);
 541
 542         /* reprotect registers */
 543         outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
 544         outb_p(vsync_end, vga_video_port_val);
 545
 546         spin_unlock_irqrestore(&vga_lock, flags);
 547
 548         return 0;
 549 }
 550
 551 static int vgacon_switch(struct vc_data *c)
 552 {
 553         /*
 554          * We need to save screen size here as it's the only way
 555          * we can spot the screen has been resized and we need to
 556          * set size of freshly allocated screens ourselves.
 557          */
 558         vga_video_num_columns = c->vc_cols;
 559         vga_video_num_lines = c->vc_rows;
 560
 561         /* We can only copy out the size of the video buffer here,
 562          * otherwise we get into VGA BIOS */
 563
 564         if (!vga_is_gfx) {
 565                 scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf,
 566                             c->vc_screenbuf_size > vga_vram_size ?
 567                                 vga_vram_size : c->vc_screenbuf_size);
 568                 vgacon_doresize(c, c->vc_cols, c->vc_rows);
 569         }
 570
 571         return 0;               /* Redrawing not needed */
 572 }
 573
 574 static void vga_set_palette(struct vc_data *vc, unsigned char *table)
 575 {
 576         int i, j;
 577
 578         for (i = j = 0; i < 16; i++) {
 579                 vga_w(state.vgabase, VGA_PEL_IW, table[i]);
 580                 vga_w(state.vgabase, VGA_PEL_D, vc->vc_palette[j++] >> 2);
 581                 vga_w(state.vgabase, VGA_PEL_D, vc->vc_palette[j++] >> 2);
 582                 vga_w(state.vgabase, VGA_PEL_D, vc->vc_palette[j++] >> 2);
 583         }
 584 }
 585
 586 static int vgacon_set_palette(struct vc_data *vc, unsigned char *table)
 587 {
 588 #ifdef CAN_LOAD_PALETTE
 589         if (vga_video_type != VIDEO_TYPE_VGAC || vga_palette_blanked
 590             || !CON_IS_VISIBLE(vc))
 591                 return -EINVAL;
 592         vga_set_palette(vc, table);
 593         return 0;
 594 #else
 595         return -EINVAL;
 596 #endif
 597 }
 598
 599 /* structure holding original VGA register settings */
 600 static struct {
 601         unsigned char SeqCtrlIndex;     /* Sequencer Index reg.   */
 602         unsigned char CrtCtrlIndex;     /* CRT-Contr. Index reg.  */
 603         unsigned char CrtMiscIO;        /* Miscellaneous register */
 604         unsigned char HorizontalTotal;  /* CRT-Controller:00h */
 605         unsigned char HorizDisplayEnd;  /* CRT-Controller:01h */
 606         unsigned char StartHorizRetrace;        /* CRT-Controller:04h */
 607         unsigned char EndHorizRetrace;  /* CRT-Controller:05h */
 608         unsigned char Overflow; /* CRT-Controller:07h */
 609         unsigned char StartVertRetrace; /* CRT-Controller:10h */
 610         unsigned char EndVertRetrace;   /* CRT-Controller:11h */
 611         unsigned char ModeControl;      /* CRT-Controller:17h */
 612         unsigned char ClockingMode;     /* Seq-Controller:01h */
 613 } vga_state;
 614
 615 static void vga_vesa_blank(struct vgastate *state, int mode)
 616 {
 617         /* save original values of VGA controller registers */
 618         if (!vga_vesa_blanked) {
 619                 spin_lock_irq(&vga_lock);
 620                 vga_state.SeqCtrlIndex = vga_r(state->vgabase, VGA_SEQ_I);
 621                 vga_state.CrtCtrlIndex = inb_p(vga_video_port_reg);
 622                 vga_state.CrtMiscIO = vga_r(state->vgabase, VGA_MIS_R);
 623                 spin_unlock_irq(&vga_lock);
 624
 625                 outb_p(0x00, vga_video_port_reg);       /* HorizontalTotal */
 626                 vga_state.HorizontalTotal = inb_p(vga_video_port_val);
 627                 outb_p(0x01, vga_video_port_reg);       /* HorizDisplayEnd */
 628                 vga_state.HorizDisplayEnd = inb_p(vga_video_port_val);
 629                 outb_p(0x04, vga_video_port_reg);       /* StartHorizRetrace */
 630                 vga_state.StartHorizRetrace = inb_p(vga_video_port_val);
 631                 outb_p(0x05, vga_video_port_reg);       /* EndHorizRetrace */
 632                 vga_state.EndHorizRetrace = inb_p(vga_video_port_val);
 633                 outb_p(0x07, vga_video_port_reg);       /* Overflow */
 634                 vga_state.Overflow = inb_p(vga_video_port_val);
 635                 outb_p(0x10, vga_video_port_reg);       /* StartVertRetrace */
 636                 vga_state.StartVertRetrace = inb_p(vga_video_port_val);
 637                 outb_p(0x11, vga_video_port_reg);       /* EndVertRetrace */
 638                 vga_state.EndVertRetrace = inb_p(vga_video_port_val);
 639                 outb_p(0x17, vga_video_port_reg);       /* ModeControl */
 640                 vga_state.ModeControl = inb_p(vga_video_port_val);
 641                 vga_state.ClockingMode = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
 642         }
 643
 644         /* assure that video is enabled */
 645         /* "0x20" is VIDEO_ENABLE_bit in register 01 of sequencer */
 646         spin_lock_irq(&vga_lock);
 647         vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, vga_state.ClockingMode | 0x20);
 648
 649         /* test for vertical retrace in process.... */
 650         if ((vga_state.CrtMiscIO & 0x80) == 0x80)
 651                 vga_w(state->vgabase, VGA_MIS_W, vga_state.CrtMiscIO & 0xEF);
 652
 653         /*
 654          * Set <End of vertical retrace> to minimum (0) and
 655          * <Start of vertical Retrace> to maximum (incl. overflow)
 656          * Result: turn off vertical sync (VSync) pulse.
 657          */
 658         if (mode & VESA_VSYNC_SUSPEND) {
 659                 outb_p(0x10, vga_video_port_reg);       /* StartVertRetrace */
 660                 outb_p(0xff, vga_video_port_val);       /* maximum value */
 661                 outb_p(0x11, vga_video_port_reg);       /* EndVertRetrace */
 662                 outb_p(0x40, vga_video_port_val);       /* minimum (bits 0..3)  */
 663                 outb_p(0x07, vga_video_port_reg);       /* Overflow */
 664                 outb_p(vga_state.Overflow | 0x84, vga_video_port_val);  /* bits 9,10 of vert. retrace */
 665         }
 666
 667         if (mode & VESA_HSYNC_SUSPEND) {
 668                 /*
 669                  * Set <End of horizontal retrace> to minimum (0) and
 670                  *  <Start of horizontal Retrace> to maximum
 671                  * Result: turn off horizontal sync (HSync) pulse.
 672                  */
 673                 outb_p(0x04, vga_video_port_reg);       /* StartHorizRetrace */
 674                 outb_p(0xff, vga_video_port_val);       /* maximum */
 675                 outb_p(0x05, vga_video_port_reg);       /* EndHorizRetrace */
 676                 outb_p(0x00, vga_video_port_val);       /* minimum (0) */
 677         }
 678
 679         /* restore both index registers */
 680         vga_w(state->vgabase, VGA_SEQ_I, vga_state.SeqCtrlIndex);
 681         outb_p(vga_state.CrtCtrlIndex, vga_video_port_reg);
 682         spin_unlock_irq(&vga_lock);
 683 }
 684
 685 static void vga_vesa_unblank(struct vgastate *state)
 686 {
 687         /* restore original values of VGA controller registers */
 688         spin_lock_irq(&vga_lock);
 689         vga_w(state->vgabase, VGA_MIS_W, vga_state.CrtMiscIO);
 690
 691         outb_p(0x00, vga_video_port_reg);       /* HorizontalTotal */
 692         outb_p(vga_state.HorizontalTotal, vga_video_port_val);
 693         outb_p(0x01, vga_video_port_reg);       /* HorizDisplayEnd */
 694         outb_p(vga_state.HorizDisplayEnd, vga_video_port_val);
 695         outb_p(0x04, vga_video_port_reg);       /* StartHorizRetrace */
 696         outb_p(vga_state.StartHorizRetrace, vga_video_port_val);
 697         outb_p(0x05, vga_video_port_reg);       /* EndHorizRetrace */
 698         outb_p(vga_state.EndHorizRetrace, vga_video_port_val);
 699         outb_p(0x07, vga_video_port_reg);       /* Overflow */
 700         outb_p(vga_state.Overflow, vga_video_port_val);
 701         outb_p(0x10, vga_video_port_reg);       /* StartVertRetrace */
 702         outb_p(vga_state.StartVertRetrace, vga_video_port_val);
 703         outb_p(0x11, vga_video_port_reg);       /* EndVertRetrace */
 704         outb_p(vga_state.EndVertRetrace, vga_video_port_val);
 705         outb_p(0x17, vga_video_port_reg);       /* ModeControl */
 706         outb_p(vga_state.ModeControl, vga_video_port_val);
 707         /* ClockingMode */
 708         vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, vga_state.ClockingMode);
 709
 710         /* restore index/control registers */
 711         vga_w(state->vgabase, VGA_SEQ_I, vga_state.SeqCtrlIndex);
 712         outb_p(vga_state.CrtCtrlIndex, vga_video_port_reg);
 713         spin_unlock_irq(&vga_lock);
 714 }
 715
 716 static void vga_pal_blank(struct vgastate *state)
 717 {
 718         int i;
 719
 720         for (i = 0; i < 16; i++) {
 721                 vga_w(state->vgabase, VGA_PEL_IW, i);
 722                 vga_w(state->vgabase, VGA_PEL_D, 0);
 723                 vga_w(state->vgabase, VGA_PEL_D, 0);
 724                 vga_w(state->vgabase, VGA_PEL_D, 0);
 725         }
 726 }
 727
 728 static int vgacon_blank(struct vc_data *c, int blank, int mode_switch)
 729 {
 730         switch (blank) {
 731         case 0:         /* Unblank */
 732                 if (vga_vesa_blanked) {
 733                         vga_vesa_unblank(&state);
 734                         vga_vesa_blanked = 0;
 735                 }
 736                 if (vga_palette_blanked) {
 737                         vga_set_palette(c, color_table);
 738                         vga_palette_blanked = 0;
 739                         return 0;
 740                 }
 741                 vga_is_gfx = 0;
 742                 /* Tell console.c that it has to restore the screen itself */
 743                 return 1;
 744         case 1:         /* Normal blanking */
 745         case -1:        /* Obsolete */
 746                 if (!mode_switch && vga_video_type == VIDEO_TYPE_VGAC) {
 747                         vga_pal_blank(&state);
 748                         vga_palette_blanked = 1;
 749                         return 0;
 750                 }
 751                 vgacon_set_origin(c);
 752                 scr_memsetw((void *) vga_vram_base, BLANK,
 753                             c->vc_screenbuf_size);
 754                 if (mode_switch)
 755                         vga_is_gfx = 1;
 756                 return 1;
 757         default:                /* VESA blanking */
 758                 if (vga_video_type == VIDEO_TYPE_VGAC) {
 759                         vga_vesa_blank(&state, blank - 1);
 760                         vga_vesa_blanked = blank;
 761                 }
 762                 return 0;
 763         }
 764 }
 765
 766 /*
 767  * PIO_FONT support.
 768  *
 769  * The font loading code goes back to the codepage package by
 770  * Joel Hoffman (joel@wam.umd.edu). (He reports that the original
 771  * reference is: "From: p. 307 of _Programmer's Guide to PC & PS/2
 772  * Video Systems_ by Richard Wilton. 1987.  Microsoft Press".)
 773  *
 774  * Change for certain monochrome monitors by Yury Shevchuck
 775  * (sizif@botik.yaroslavl.su).
 776  */
 777
 778 #ifdef CAN_LOAD_EGA_FONTS
 779
 780 #define colourmap 0xa0000
 781 /* Pauline Middelink <middelin@polyware.iaf.nl> reports that we
 782    should use 0xA0000 for the bwmap as well.. */
 783 #define blackwmap 0xa0000
 784 #define cmapsz 8192
 785
 786 static int vgacon_do_font_op(struct vgastate *state,char *arg,int set,int ch512)
 787 {
 788         unsigned short video_port_status = vga_video_port_reg + 6;
 789         int font_select = 0x00, beg, i;
 790         char *charmap;
 791
 792         if (vga_video_type != VIDEO_TYPE_EGAM) {
 793                 charmap = (char *) VGA_MAP_MEM(colourmap);
 794                 beg = 0x0e;
 795 #ifdef VGA_CAN_DO_64KB
 796                 if (vga_video_type == VIDEO_TYPE_VGAC)
 797                         beg = 0x06;
 798 #endif
 799         } else {
 800                 charmap = (char *) VGA_MAP_MEM(blackwmap);
 801                 beg = 0x0a;
 802         }
 803
 804 #ifdef BROKEN_GRAPHICS_PROGRAMS
 805         /*
 806          * All fonts are loaded in slot 0 (0:1 for 512 ch)
 807          */
 808
 809         if (!arg)
 810                 return -EINVAL; /* Return to default font not supported */
 811
 812         vga_font_is_default = 0;
 813         font_select = ch512 ? 0x04 : 0x00;
 814 #else
 815         /*
 816          * The default font is kept in slot 0 and is never touched.
 817          * A custom font is loaded in slot 2 (256 ch) or 2:3 (512 ch)
 818          */
 819
 820         if (set) {
 821                 vga_font_is_default = !arg;
 822                 if (!arg)
 823                         ch512 = 0;      /* Default font is always 256 */
 824                 font_select = arg ? (ch512 ? 0x0e : 0x0a) : 0x00;
 825         }
 826
 827         if (!vga_font_is_default)
 828                 charmap += 4 * cmapsz;
 829 #endif
 830
 831         unlock_kernel();
 832         spin_lock_irq(&vga_lock);
 833         /* First, the Sequencer */
 834         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
 835         /* CPU writes only to map 2 */
 836         vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x04);
 837         /* Sequential addressing */
 838         vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x07);
 839         /* Clear synchronous reset */
 840         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x03);
 841
 842         /* Now, the graphics controller, select map 2 */
 843         vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x02);
 844         /* disable odd-even addressing */
 845         vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x00);
 846         /* map start at A000:0000 */
 847         vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x00);
 848         spin_unlock_irq(&vga_lock);
 849
 850         if (arg) {
 851                 if (set)
 852                         for (i = 0; i < cmapsz; i++)
 853                                 vga_writeb(arg[i], charmap + i);
 854                 else
 855                         for (i = 0; i < cmapsz; i++)
 856                                 arg[i] = vga_readb(charmap + i);
 857
 858                 /*
 859                  * In 512-character mode, the character map is not contiguous if
 860                  * we want to remain EGA compatible -- which we do
 861                  */
 862
 863                 if (ch512) {
 864                         charmap += 2 * cmapsz;
 865                         arg += cmapsz;
 866                         if (set)
 867                                 for (i = 0; i < cmapsz; i++)
 868                                         vga_writeb(arg[i], charmap + i);
 869                         else
 870                                 for (i = 0; i < cmapsz; i++)
 871                                         arg[i] = vga_readb(charmap + i);
 872                 }
 873         }
 874
 875         spin_lock_irq(&vga_lock);
 876         /* First, the sequencer, Synchronous reset */
 877         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x01);
 878         /* CPU writes to maps 0 and 1 */
 879         vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x03);
 880         /* odd-even addressing */
 881         vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x03);
 882         /* Character Map Select */
 883         if (set)
 884                 vga_wseq(state->vgabase, VGA_SEQ_CHARACTER_MAP, font_select);
 885         /* clear synchronous reset */
 886         vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x03);
 887
 888         /* Now, the graphics controller, select map 0 for CPU */
 889         vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x00);
 890         /* enable even-odd addressing */
 891         vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x10);
 892         /* map starts at b800:0 or b000:0 */
 893         vga_wgfx(state->vgabase, VGA_GFX_MISC, beg);
 894
 895         /* if 512 char mode is already enabled don't re-enable it. */
 896         if ((set) && (ch512 != vga_512_chars)) {
 897                 int i;
 898
 899                 /* attribute controller */
 900                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 901                         struct vc_data *c = vc_cons[i].d;
 902                         if (c && c->vc_sw == &vga_con)
 903                                 c->vc_hi_font_mask = ch512 ? 0x0800 : 0;
 904                 }
 905                 vga_512_chars = ch512;
 906                 /* 256-char: enable intensity bit
 907                    512-char: disable intensity bit */
 908                 inb_p(video_port_status);       /* clear address flip-flop */
 909                 /* color plane enable register */
 910                 vga_wattr(state->vgabase, VGA_ATC_PLANE_ENABLE, ch512 ? 0x07 : 0x0f);
 911                 /* Wilton (1987) mentions the following; I don't know what
 912                    it means, but it works, and it appears necessary */
 913                 inb_p(video_port_status);
 914                 vga_wattr(state->vgabase, VGA_AR_ENABLE_DISPLAY, 0);
 915         }
 916         spin_unlock_irq(&vga_lock);
 917         lock_kernel();
 918         return 0;
 919 }
 920
 921 /*
 922  * Adjust the screen to fit a font of a certain height
 923  */
 924 static int vgacon_adjust_height(struct vc_data *vc, unsigned fontheight)
 925 {
 926         unsigned char ovr, vde, fsr;
 927         int rows, maxscan, i;
 928
 929         rows = vc->vc_scan_lines / fontheight;  /* Number of video rows we end up with */
 930         maxscan = rows * fontheight - 1;        /* Scan lines to actually display-1 */
 931
 932         /* Reprogram the CRTC for the new font size
 933            Note: the attempt to read the overflow register will fail
 934            on an EGA, but using 0xff for the previous value appears to
 935            be OK for EGA text modes in the range 257-512 scan lines, so I
 936            guess we don't need to worry about it.
 937
 938            The same applies for the spill bits in the font size and cursor
 939            registers; they are write-only on EGA, but it appears that they
 940            are all don't care bits on EGA, so I guess it doesn't matter. */
 941
 942         spin_lock_irq(&vga_lock);
 943         outb_p(0x07, vga_video_port_reg);       /* CRTC overflow register */
 944         ovr = inb_p(vga_video_port_val);
 945         outb_p(0x09, vga_video_port_reg);       /* Font size register */
 946         fsr = inb_p(vga_video_port_val);
 947         spin_unlock_irq(&vga_lock);
 948
 949         vde = maxscan & 0xff;   /* Vertical display end reg */
 950         ovr = (ovr & 0xbd) +    /* Overflow register */
 951             ((maxscan & 0x100) >> 7) + ((maxscan & 0x200) >> 3);
 952         fsr = (fsr & 0xe0) + (fontheight - 1);  /*  Font size register */
 953
 954         spin_lock_irq(&vga_lock);
 955         outb_p(0x07, vga_video_port_reg);       /* CRTC overflow register */
 956         outb_p(ovr, vga_video_port_val);
 957         outb_p(0x09, vga_video_port_reg);       /* Font size */
 958         outb_p(fsr, vga_video_port_val);
 959         outb_p(0x12, vga_video_port_reg);       /* Vertical display limit */
 960         outb_p(vde, vga_video_port_val);
 961         spin_unlock_irq(&vga_lock);
 962
 963         for (i = 0; i < MAX_NR_CONSOLES; i++) {
 964                 struct vc_data *c = vc_cons[i].d;
 965
 966                 if (c && c->vc_sw == &vga_con) {
 967                         if (CON_IS_VISIBLE(c)) {
 968                                 /* void size to cause regs to be rewritten */
 969                                 cursor_size_lastfrom = 0;
 970                                 cursor_size_lastto = 0;
 971                                 c->vc_sw->con_cursor(c, CM_DRAW);
 972                         }
 973                         c->vc_font.height = fontheight;
 974                         vc_resize(c, 0, rows);  /* Adjust console size */
 975                 }
 976         }
 977         return 0;
 978 }
 979
 980 static int vgacon_font_set(struct vc_data *c, struct console_font *font, unsigned flags)
 981 {
 982         unsigned charcount = font->charcount;
 983         int rc;
 984
 985         if (vga_video_type < VIDEO_TYPE_EGAM)
 986                 return -EINVAL;
 987
 988         if (font->width != 8 || (charcount != 256 && charcount != 512))
 989                 return -EINVAL;
 990
 991         rc = vgacon_do_font_op(&state, font->data, 1, charcount == 512);
 992         if (rc)
 993                 return rc;
 994
 995         if (!(flags & KD_FONT_FLAG_DONT_RECALC))
 996                 rc = vgacon_adjust_height(c, font->height);
 997         return rc;
 998 }
 999
1000 static int vgacon_font_get(struct vc_data *c, struct console_font *font)
1001 {
1002         if (vga_video_type < VIDEO_TYPE_EGAM)
1003                 return -EINVAL;
1004
1005         font->width = 8;
1006         font->height = c->vc_font.height;
1007         font->charcount = vga_512_chars ? 512 : 256;
1008         if (!font->data)
1009                 return 0;
1010         return vgacon_do_font_op(&state, font->data, 0, 0);
1011 }
1012
1013 #else
1014
1015 #define vgacon_font_set NULL
1016 #define vgacon_font_get NULL
1017
1018 #endif
1019
1020 static int vgacon_resize(struct vc_data *c, unsigned int width,
1021                                 unsigned int height)
1022 {
1023         if (width % 2 || width > ORIG_VIDEO_COLS || height > ORIG_VIDEO_LINES)
1024                 return -EINVAL;
1025
1026         if (CON_IS_VISIBLE(c) && !vga_is_gfx) /* who knows */
1027                 vgacon_doresize(c, width, height);
1028         return 0;
1029 }
1030
1031 static int vgacon_scrolldelta(struct vc_data *c, int lines)
1032 {
1033         if (!lines)             /* Turn scrollback off */
1034                 c->vc_visible_origin = c->vc_origin;
1035         else {
1036                 int margin = c->vc_size_row * 4;
1037                 int ul, we, p, st;
1038
1039                 if (vga_rolled_over >
1040                     (c->vc_scr_end - vga_vram_base) + margin) {
1041                         ul = c->vc_scr_end - vga_vram_base;
1042                         we = vga_rolled_over + c->vc_size_row;
1043                 } else {
1044                         ul = 0;
1045                         we = vga_vram_size;
1046                 }
1047                 p = (c->vc_visible_origin - vga_vram_base - ul + we) % we +
1048                     lines * c->vc_size_row;
1049                 st = (c->vc_origin - vga_vram_base - ul + we) % we;
1050                 if (st < 2 * margin)
1051                         margin = 0;
1052                 if (p < margin)
1053                         p = 0;
1054                 if (p > st - margin)
1055                         p = st;
1056                 c->vc_visible_origin = vga_vram_base + (p + ul) % we;
1057         }
1058         vga_set_mem_top(c);
1059         return 1;
1060 }
1061
1062 static int vgacon_set_origin(struct vc_data *c)
1063 {
1064         if (vga_is_gfx ||       /* We don't play origin tricks in graphic modes */
1065             (console_blanked && !vga_palette_blanked))  /* Nor we write to blanked screens */
1066                 return 0;
1067         c->vc_origin = c->vc_visible_origin = vga_vram_base;
1068         vga_set_mem_top(c);
1069         vga_rolled_over = 0;
1070         return 1;
1071 }
1072
1073 static void vgacon_save_screen(struct vc_data *c)
1074 {
1075         static int vga_bootup_console = 0;
1076
1077         if (!vga_bootup_console) {
1078                 /* This is a gross hack, but here is the only place we can
1079                  * set bootup console parameters without messing up generic
1080                  * console initialization routines.
1081                  */
1082                 vga_bootup_console = 1;
1083                 c->vc_x = ORIG_X;
1084                 c->vc_y = ORIG_Y;
1085         }
1086
1087         /* We can't copy in more then the size of the video buffer,
1088          * or we'll be copying in VGA BIOS */
1089
1090         if (!vga_is_gfx)
1091                 scr_memcpyw((u16 *) c->vc_screenbuf, (u16 *) c->vc_origin,
1092                             c->vc_screenbuf_size > vga_vram_size ? vga_vram_size : c->vc_screenbuf_size);
1093 }
1094
1095 static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,
1096                          int lines)
1097 {
1098         unsigned long oldo;
1099         unsigned int delta;
1100
1101         if (t || b != c->vc_rows || vga_is_gfx)
1102                 return 0;
1103
1104         if (c->vc_origin != c->vc_visible_origin)
1105                 vgacon_scrolldelta(c, 0);
1106
1107         if (!vga_hardscroll_enabled || lines >= c->vc_rows / 2)
1108                 return 0;
1109
1110         oldo = c->vc_origin;
1111         delta = lines * c->vc_size_row;
1112         if (dir == SM_UP) {
1113                 if (c->vc_scr_end + delta >= vga_vram_end) {
1114                         scr_memcpyw((u16 *) vga_vram_base,
1115                                     (u16 *) (oldo + delta),
1116                                     c->vc_screenbuf_size - delta);
1117                         c->vc_origin = vga_vram_base;
1118                         vga_rolled_over = oldo - vga_vram_base;
1119                 } else
1120                         c->vc_origin += delta;
1121                 scr_memsetw((u16 *) (c->vc_origin + c->vc_screenbuf_size -
1122                                      delta), c->vc_video_erase_char,
1123                             delta);
1124         } else {
1125                 if (oldo - delta < vga_vram_base) {
1126                         scr_memmovew((u16 *) (vga_vram_end -
1127                                               c->vc_screenbuf_size +
1128                                               delta), (u16 *) oldo,
1129                                      c->vc_screenbuf_size - delta);
1130                         c->vc_origin = vga_vram_end - c->vc_screenbuf_size;
1131                         vga_rolled_over = 0;
1132                 } else
1133                         c->vc_origin -= delta;
1134                 c->vc_scr_end = c->vc_origin + c->vc_screenbuf_size;
1135                 scr_memsetw((u16 *) (c->vc_origin), c->vc_video_erase_char,
1136                             delta);
1137         }
1138         c->vc_scr_end = c->vc_origin + c->vc_screenbuf_size;
1139         c->vc_visible_origin = c->vc_origin;
1140         vga_set_mem_top(c);
1141         c->vc_pos = (c->vc_pos - oldo) + c->vc_origin;
1142         return 1;
1143 }
1144
1145
1146 /*
1147  *  The console `switch' structure for the VGA based console
1148  */
1149
1150 static int vgacon_dummy(struct vc_data *c)
1151 {
1152         return 0;
1153 }
1154
1155 #define DUMMY (void *) vgacon_dummy
1156
1157 const struct consw vga_con = {
1158         .owner = THIS_MODULE,
1159         .con_startup = vgacon_startup,
1160         .con_init = vgacon_init,
1161         .con_deinit = vgacon_deinit,
1162         .con_clear = DUMMY,
1163         .con_putc = DUMMY,
1164         .con_putcs = DUMMY,
1165         .con_cursor = vgacon_cursor,
1166         .con_scroll = vgacon_scroll,
1167         .con_bmove = DUMMY,
1168         .con_switch = vgacon_switch,
1169         .con_blank = vgacon_blank,
1170         .con_font_set = vgacon_font_set,
1171         .con_font_get = vgacon_font_get,
1172         .con_resize = vgacon_resize,
1173         .con_set_palette = vgacon_set_palette,
1174         .con_scrolldelta = vgacon_scrolldelta,
1175         .con_set_origin = vgacon_set_origin,
1176         .con_save_screen = vgacon_save_screen,
1177         .con_build_attr = vgacon_build_attr,
1178         .con_invert_region = vgacon_invert_region,
1179 };
1180
1181 MODULE_LICENSE("GPL");