drivers/char/nvram.c

   1 /*
   2  * CMOS/NV-RAM driver for Linux
   3  *
   4  * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
   5  * idea by and with help from Richard Jelinek <rj@suse.de>
   6  * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com)
   7  *
   8  * This driver allows you to access the contents of the non-volatile memory in
   9  * the mc146818rtc.h real-time clock. This chip is built into all PCs and into
  10  * many Atari machines. In the former it's called "CMOS-RAM", in the latter
  11  * "NVRAM" (NV stands for non-volatile).
  12  *
  13  * The data are supplied as a (seekable) character device, /dev/nvram. The
  14  * size of this file is dependent on the controller.  The usual size is 114,
  15  * the number of freely available bytes in the memory (i.e., not used by the
  16  * RTC itself).
  17  *
  18  * Checksums over the NVRAM contents are managed by this driver. In case of a
  19  * bad checksum, reads and writes return -EIO. The checksum can be initialized
  20  * to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or
  21  * ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid
  22  * again; use with care!)
  23  *
  24  * This file also provides some functions for other parts of the kernel that
  25  * want to access the NVRAM: nvram_{read,write,check_checksum,set_checksum}.
  26  * Obviously this can be used only if this driver is always configured into
  27  * the kernel and is not a module. Since the functions are used by some Atari
  28  * drivers, this is the case on the Atari.
  29  *
  30  *
  31  *      1.1     Cesar Barros: SMP locking fixes
  32  *              added changelog
  33  *      1.2     Erik Gilling: Cobalt Networks support
  34  *              Tim Hockin: general cleanup, Cobalt support
  35  *      1.3     Wim Van Sebroeck: convert PRINT_PROC to seq_file
  36  */
  37
  38 #define NVRAM_VERSION   "1.3"
  39
  40 #include <linux/module.h>
  41 #include <linux/smp_lock.h>
  42 #include <linux/nvram.h>
  43
  44 #define PC              1
  45 #define ATARI           2
  46
  47 /* select machine configuration */
  48 #if defined(CONFIG_ATARI)
  49 #  define MACH ATARI
  50 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)  /* and ?? */
  51 #  define MACH PC
  52 #else
  53 #  error Cannot build nvram driver for this machine configuration.
  54 #endif
  55
  56 #if MACH == PC
  57
  58 /* RTC in a PC */
  59 #define CHECK_DRIVER_INIT()     1
  60
  61 /* On PCs, the checksum is built only over bytes 2..31 */
  62 #define PC_CKS_RANGE_START      2
  63 #define PC_CKS_RANGE_END        31
  64 #define PC_CKS_LOC              32
  65 #define NVRAM_BYTES             (128-NVRAM_FIRST_BYTE)
  66
  67 #define mach_check_checksum     pc_check_checksum
  68 #define mach_set_checksum       pc_set_checksum
  69 #define mach_proc_infos         pc_proc_infos
  70
  71 #endif
  72
  73 #if MACH == ATARI
  74
  75 /* Special parameters for RTC in Atari machines */
  76 #include <asm/atarihw.h>
  77 #include <asm/atariints.h>
  78 #define RTC_PORT(x)             (TT_RTC_BAS + 2*(x))
  79 #define CHECK_DRIVER_INIT()     (MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))
  80
  81 #define NVRAM_BYTES             50
  82
  83 /* On Ataris, the checksum is over all bytes except the checksum bytes
  84  * themselves; these are at the very end */
  85 #define ATARI_CKS_RANGE_START   0
  86 #define ATARI_CKS_RANGE_END     47
  87 #define ATARI_CKS_LOC           48
  88
  89 #define mach_check_checksum     atari_check_checksum
  90 #define mach_set_checksum       atari_set_checksum
  91 #define mach_proc_infos         atari_proc_infos
  92
  93 #endif
  94
  95 /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
  96  * rtc_lock held. Due to the index-port/data-port design of the RTC, we
  97  * don't want two different things trying to get to it at once. (e.g. the
  98  * periodic 11 min sync from time.c vs. this driver.)
  99  */
 100
 101 #include <linux/types.h>
 102 #include <linux/errno.h>
 103 #include <linux/miscdevice.h>
 104 #include <linux/slab.h>
 105 #include <linux/ioport.h>
 106 #include <linux/fcntl.h>
 107 #include <linux/mc146818rtc.h>
 108 #include <linux/init.h>
 109 #include <linux/proc_fs.h>
 110 #include <linux/seq_file.h>
 111 #include <linux/spinlock.h>
 112 #include <linux/io.h>
 113 #include <linux/uaccess.h>
 114
 115 #include <asm/system.h>
 116
 117 static DEFINE_SPINLOCK(nvram_state_lock);
 118 static int nvram_open_cnt;      /* #times opened */
 119 static int nvram_open_mode;     /* special open modes */
 120 #define NVRAM_WRITE             1 /* opened for writing (exclusive) */
 121 #define NVRAM_EXCL              2 /* opened with O_EXCL */
 122
 123 static int mach_check_checksum(void);
 124 static void mach_set_checksum(void);
 125
 126 #ifdef CONFIG_PROC_FS
 127 static void mach_proc_infos(unsigned char *contents, struct seq_file *seq,
 128                                                                 void *offset);
 129 #endif
 130
 131 /*
 132  * These functions are provided to be called internally or by other parts of
 133  * the kernel. It's up to the caller to ensure correct checksum before reading
 134  * or after writing (needs to be done only once).
 135  *
 136  * It is worth noting that these functions all access bytes of general
 137  * purpose memory in the NVRAM - that is to say, they all add the
 138  * NVRAM_FIRST_BYTE offset.  Pass them offsets into NVRAM as if you did not
 139  * know about the RTC cruft.
 140  */
 141
 142 unsigned char __nvram_read_byte(int i)
 143 {
 144         return CMOS_READ(NVRAM_FIRST_BYTE + i);
 145 }
 146 EXPORT_SYMBOL(__nvram_read_byte);
 147
 148 unsigned char nvram_read_byte(int i)
 149 {
 150         unsigned long flags;
 151         unsigned char c;
 152
 153         spin_lock_irqsave(&rtc_lock, flags);
 154         c = __nvram_read_byte(i);
 155         spin_unlock_irqrestore(&rtc_lock, flags);
 156         return c;
 157 }
 158 EXPORT_SYMBOL(nvram_read_byte);
 159
 160 /* This races nicely with trying to read with checksum checking (nvram_read) */
 161 void __nvram_write_byte(unsigned char c, int i)
 162 {
 163         CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
 164 }
 165 EXPORT_SYMBOL(__nvram_write_byte);
 166
 167 void nvram_write_byte(unsigned char c, int i)
 168 {
 169         unsigned long flags;
 170
 171         spin_lock_irqsave(&rtc_lock, flags);
 172         __nvram_write_byte(c, i);
 173         spin_unlock_irqrestore(&rtc_lock, flags);
 174 }
 175 EXPORT_SYMBOL(nvram_write_byte);
 176
 177 int __nvram_check_checksum(void)
 178 {
 179         return mach_check_checksum();
 180 }
 181 EXPORT_SYMBOL(__nvram_check_checksum);
 182
 183 int nvram_check_checksum(void)
 184 {
 185         unsigned long flags;
 186         int rv;
 187
 188         spin_lock_irqsave(&rtc_lock, flags);
 189         rv = __nvram_check_checksum();
 190         spin_unlock_irqrestore(&rtc_lock, flags);
 191         return rv;
 192 }
 193 EXPORT_SYMBOL(nvram_check_checksum);
 194
 195 static void __nvram_set_checksum(void)
 196 {
 197         mach_set_checksum();
 198 }
 199
 200 #if 0
 201 void nvram_set_checksum(void)
 202 {
 203         unsigned long flags;
 204
 205         spin_lock_irqsave(&rtc_lock, flags);
 206         __nvram_set_checksum();
 207         spin_unlock_irqrestore(&rtc_lock, flags);
 208 }
 209 #endif  /*  0  */
 210
 211 /*
 212  * The are the file operation function for user access to /dev/nvram
 213  */
 214
 215 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
 216 {
 217         lock_kernel();
 218         switch (origin) {
 219         case 0:
 220                 /* nothing to do */
 221                 break;
 222         case 1:
 223                 offset += file->f_pos;
 224                 break;
 225         case 2:
 226                 offset += NVRAM_BYTES;
 227                 break;
 228         }
 229         unlock_kernel();
 230         return (offset >= 0) ? (file->f_pos = offset) : -EINVAL;
 231 }
 232
 233 static ssize_t nvram_read(struct file *file, char __user *buf,
 234                                                 size_t count, loff_t *ppos)
 235 {
 236         unsigned char contents[NVRAM_BYTES];
 237         unsigned i = *ppos;
 238         unsigned char *tmp;
 239
 240         spin_lock_irq(&rtc_lock);
 241
 242         if (!__nvram_check_checksum())
 243                 goto checksum_err;
 244
 245         for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
 246                 *tmp = __nvram_read_byte(i);
 247
 248         spin_unlock_irq(&rtc_lock);
 249
 250         if (copy_to_user(buf, contents, tmp - contents))
 251                 return -EFAULT;
 252
 253         *ppos = i;
 254
 255         return tmp - contents;
 256
 257 checksum_err:
 258         spin_unlock_irq(&rtc_lock);
 259         return -EIO;
 260 }
 261
 262 static ssize_t nvram_write(struct file *file, const char __user *buf,
 263                                                 size_t count, loff_t *ppos)
 264 {
 265         unsigned char contents[NVRAM_BYTES];
 266         unsigned i = *ppos;
 267         unsigned char *tmp;
 268         int len;
 269
 270         len = (NVRAM_BYTES - i) < count ? (NVRAM_BYTES - i) : count;
 271         if (copy_from_user(contents, buf, len))
 272                 return -EFAULT;
 273
 274         spin_lock_irq(&rtc_lock);
 275
 276         if (!__nvram_check_checksum())
 277                 goto checksum_err;
 278
 279         for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
 280                 __nvram_write_byte(*tmp, i);
 281
 282         __nvram_set_checksum();
 283
 284         spin_unlock_irq(&rtc_lock);
 285
 286         *ppos = i;
 287
 288         return tmp - contents;
 289
 290 checksum_err:
 291         spin_unlock_irq(&rtc_lock);
 292         return -EIO;
 293 }
 294
 295 static int nvram_ioctl(struct inode *inode, struct file *file,
 296                                         unsigned int cmd, unsigned long arg)
 297 {
 298         int i;
 299
 300         switch (cmd) {
 301
 302         case NVRAM_INIT:
 303                 /* initialize NVRAM contents and checksum */
 304                 if (!capable(CAP_SYS_ADMIN))
 305                         return -EACCES;
 306
 307                 spin_lock_irq(&rtc_lock);
 308
 309                 for (i = 0; i < NVRAM_BYTES; ++i)
 310                         __nvram_write_byte(0, i);
 311                 __nvram_set_checksum();
 312
 313                 spin_unlock_irq(&rtc_lock);
 314                 return 0;
 315
 316         case NVRAM_SETCKS:
 317                 /* just set checksum, contents unchanged (maybe useful after
 318                  * checksum garbaged somehow...) */
 319                 if (!capable(CAP_SYS_ADMIN))
 320                         return -EACCES;
 321
 322                 spin_lock_irq(&rtc_lock);
 323                 __nvram_set_checksum();
 324                 spin_unlock_irq(&rtc_lock);
 325                 return 0;
 326
 327         default:
 328                 return -ENOTTY;
 329         }
 330 }
 331
 332 static int nvram_open(struct inode *inode, struct file *file)
 333 {
 334         lock_kernel();
 335         spin_lock(&nvram_state_lock);
 336
 337         if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
 338             (nvram_open_mode & NVRAM_EXCL) ||
 339             ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
 340                 spin_unlock(&nvram_state_lock);
 341                 unlock_kernel();
 342                 return -EBUSY;
 343         }
 344
 345         if (file->f_flags & O_EXCL)
 346                 nvram_open_mode |= NVRAM_EXCL;
 347         if (file->f_mode & FMODE_WRITE)
 348                 nvram_open_mode |= NVRAM_WRITE;
 349         nvram_open_cnt++;
 350
 351         spin_unlock(&nvram_state_lock);
 352         unlock_kernel();
 353
 354         return 0;
 355 }
 356
 357 static int nvram_release(struct inode *inode, struct file *file)
 358 {
 359         spin_lock(&nvram_state_lock);
 360
 361         nvram_open_cnt--;
 362
 363         /* if only one instance is open, clear the EXCL bit */
 364         if (nvram_open_mode & NVRAM_EXCL)
 365                 nvram_open_mode &= ~NVRAM_EXCL;
 366         if (file->f_mode & FMODE_WRITE)
 367                 nvram_open_mode &= ~NVRAM_WRITE;
 368
 369         spin_unlock(&nvram_state_lock);
 370
 371         return 0;
 372 }
 373
 374 #ifndef CONFIG_PROC_FS
 375 static int nvram_add_proc_fs(void)
 376 {
 377         return 0;
 378 }
 379
 380 #else
 381
 382 static int nvram_proc_read(struct seq_file *seq, void *offset)
 383 {
 384         unsigned char contents[NVRAM_BYTES];
 385         int i = 0;
 386
 387         spin_lock_irq(&rtc_lock);
 388         for (i = 0; i < NVRAM_BYTES; ++i)
 389                 contents[i] = __nvram_read_byte(i);
 390         spin_unlock_irq(&rtc_lock);
 391
 392         mach_proc_infos(contents, seq, offset);
 393
 394         return 0;
 395 }
 396
 397 static int nvram_proc_open(struct inode *inode, struct file *file)
 398 {
 399         return single_open(file, nvram_proc_read, NULL);
 400 }
 401
 402 static const struct file_operations nvram_proc_fops = {
 403         .owner          = THIS_MODULE,
 404         .open           = nvram_proc_open,
 405         .read           = seq_read,
 406         .llseek         = seq_lseek,
 407         .release        = single_release,
 408 };
 409
 410 static int nvram_add_proc_fs(void)
 411 {
 412         if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops))
 413                 return -ENOMEM;
 414         return 0;
 415 }
 416
 417 #endif /* CONFIG_PROC_FS */
 418
 419 static const struct file_operations nvram_fops = {
 420         .owner          = THIS_MODULE,
 421         .llseek         = nvram_llseek,
 422         .read           = nvram_read,
 423         .write          = nvram_write,
 424         .ioctl          = nvram_ioctl,
 425         .open           = nvram_open,
 426         .release        = nvram_release,
 427 };
 428
 429 static struct miscdevice nvram_dev = {
 430         NVRAM_MINOR,
 431         "nvram",
 432         &nvram_fops
 433 };
 434
 435 static int __init nvram_init(void)
 436 {
 437         int ret;
 438
 439         /* First test whether the driver should init at all */
 440         if (!CHECK_DRIVER_INIT())
 441                 return -ENODEV;
 442
 443         ret = misc_register(&nvram_dev);
 444         if (ret) {
 445                 printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
 446                     NVRAM_MINOR);
 447                 goto out;
 448         }
 449         ret = nvram_add_proc_fs();
 450         if (ret) {
 451                 printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n");
 452                 goto outmisc;
 453         }
 454         ret = 0;
 455         printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n");
 456 out:
 457         return ret;
 458 outmisc:
 459         misc_deregister(&nvram_dev);
 460         goto out;
 461 }
 462
 463 static void __exit nvram_cleanup_module(void)
 464 {
 465         remove_proc_entry("driver/nvram", NULL);
 466         misc_deregister(&nvram_dev);
 467 }
 468
 469 module_init(nvram_init);
 470 module_exit(nvram_cleanup_module);
 471
 472 /*
 473  * Machine specific functions
 474  */
 475
 476 #if MACH == PC
 477
 478 static int pc_check_checksum(void)
 479 {
 480         int i;
 481         unsigned short sum = 0;
 482         unsigned short expect;
 483
 484         for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
 485                 sum += __nvram_read_byte(i);
 486         expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
 487             __nvram_read_byte(PC_CKS_LOC+1);
 488         return (sum & 0xffff) == expect;
 489 }
 490
 491 static void pc_set_checksum(void)
 492 {
 493         int i;
 494         unsigned short sum = 0;
 495
 496         for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
 497                 sum += __nvram_read_byte(i);
 498         __nvram_write_byte(sum >> 8, PC_CKS_LOC);
 499         __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
 500 }
 501
 502 #ifdef CONFIG_PROC_FS
 503
 504 static char *floppy_types[] = {
 505         "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M",
 506         "3.5'' 2.88M", "3.5'' 2.88M"
 507 };
 508
 509 static char *gfx_types[] = {
 510         "EGA, VGA, ... (with BIOS)",
 511         "CGA (40 cols)",
 512         "CGA (80 cols)",
 513         "monochrome",
 514 };
 515
 516 static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq,
 517                                                                 void *offset)
 518 {
 519         int checksum;
 520         int type;
 521
 522         spin_lock_irq(&rtc_lock);
 523         checksum = __nvram_check_checksum();
 524         spin_unlock_irq(&rtc_lock);
 525
 526         seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not ");
 527
 528         seq_printf(seq, "# floppies     : %d\n",
 529             (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0);
 530         seq_printf(seq, "Floppy 0 type  : ");
 531         type = nvram[2] >> 4;
 532         if (type < ARRAY_SIZE(floppy_types))
 533                 seq_printf(seq, "%s\n", floppy_types[type]);
 534         else
 535                 seq_printf(seq, "%d (unknown)\n", type);
 536         seq_printf(seq, "Floppy 1 type  : ");
 537         type = nvram[2] & 0x0f;
 538         if (type < ARRAY_SIZE(floppy_types))
 539                 seq_printf(seq, "%s\n", floppy_types[type]);
 540         else
 541                 seq_printf(seq, "%d (unknown)\n", type);
 542
 543         seq_printf(seq, "HD 0 type      : ");
 544         type = nvram[4] >> 4;
 545         if (type)
 546                 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type);
 547         else
 548                 seq_printf(seq, "none\n");
 549
 550         seq_printf(seq, "HD 1 type      : ");
 551         type = nvram[4] & 0x0f;
 552         if (type)
 553                 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type);
 554         else
 555                 seq_printf(seq, "none\n");
 556
 557         seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
 558             nvram[18] | (nvram[19] << 8),
 559             nvram[20], nvram[25],
 560             nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8));
 561         seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
 562             nvram[39] | (nvram[40] << 8),
 563             nvram[41], nvram[46],
 564             nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8));
 565
 566         seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8));
 567         seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n",
 568             nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8));
 569
 570         seq_printf(seq, "Gfx adapter    : %s\n",
 571             gfx_types[(nvram[6] >> 4) & 3]);
 572
 573         seq_printf(seq, "FPU            : %sinstalled\n",
 574             (nvram[6] & 2) ? "" : "not ");
 575
 576         return;
 577 }
 578 #endif
 579
 580 #endif /* MACH == PC */
 581
 582 #if MACH == ATARI
 583
 584 static int atari_check_checksum(void)
 585 {
 586         int i;
 587         unsigned char sum = 0;
 588
 589         for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
 590                 sum += __nvram_read_byte(i);
 591         return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
 592             (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
 593 }
 594
 595 static void atari_set_checksum(void)
 596 {
 597         int i;
 598         unsigned char sum = 0;
 599
 600         for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
 601                 sum += __nvram_read_byte(i);
 602         __nvram_write_byte(~sum, ATARI_CKS_LOC);
 603         __nvram_write_byte(sum, ATARI_CKS_LOC + 1);
 604 }
 605
 606 #ifdef CONFIG_PROC_FS
 607
 608 static struct {
 609         unsigned char val;
 610         char *name;
 611 } boot_prefs[] = {
 612         { 0x80, "TOS" },
 613         { 0x40, "ASV" },
 614         { 0x20, "NetBSD (?)" },
 615         { 0x10, "Linux" },
 616         { 0x00, "unspecified" }
 617 };
 618
 619 static char *languages[] = {
 620         "English (US)",
 621         "German",
 622         "French",
 623         "English (UK)",
 624         "Spanish",
 625         "Italian",
 626         "6 (undefined)",
 627         "Swiss (French)",
 628         "Swiss (German)"
 629 };
 630
 631 static char *dateformat[] = {
 632         "MM%cDD%cYY",
 633         "DD%cMM%cYY",
 634         "YY%cMM%cDD",
 635         "YY%cDD%cMM",
 636         "4 (undefined)",
 637         "5 (undefined)",
 638         "6 (undefined)",
 639         "7 (undefined)"
 640 };
 641
 642 static char *colors[] = {
 643         "2", "4", "16", "256", "65536", "??", "??", "??"
 644 };
 645
 646 static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq,
 647                                                                 void *offset)
 648 {
 649         int checksum = nvram_check_checksum();
 650         int i;
 651         unsigned vmode;
 652
 653         seq_printf(seq, "Checksum status  : %svalid\n", checksum ? "" : "not ");
 654
 655         seq_printf(seq, "Boot preference  : ");
 656         for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
 657                 if (nvram[1] == boot_prefs[i].val) {
 658                         seq_printf(seq, "%s\n", boot_prefs[i].name);
 659                         break;
 660                 }
 661         }
 662         if (i < 0)
 663                 seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
 664
 665         seq_printf(seq, "SCSI arbitration : %s\n",
 666             (nvram[16] & 0x80) ? "on" : "off");
 667         seq_printf(seq, "SCSI host ID     : ");
 668         if (nvram[16] & 0x80)
 669                 seq_printf(seq, "%d\n", nvram[16] & 7);
 670         else
 671                 seq_printf(seq, "n/a\n");
 672
 673         /* the following entries are defined only for the Falcon */
 674         if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
 675                 return;
 676
 677         seq_printf(seq, "OS language      : ");
 678         if (nvram[6] < ARRAY_SIZE(languages))
 679                 seq_printf(seq, "%s\n", languages[nvram[6]]);
 680         else
 681                 seq_printf(seq, "%u (undefined)\n", nvram[6]);
 682         seq_printf(seq, "Keyboard language: ");
 683         if (nvram[7] < ARRAY_SIZE(languages))
 684                 seq_printf(seq, "%s\n", languages[nvram[7]]);
 685         else
 686                 seq_printf(seq, "%u (undefined)\n", nvram[7]);
 687         seq_printf(seq, "Date format      : ");
 688         seq_printf(seq, dateformat[nvram[8] & 7],
 689             nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
 690         seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
 691         seq_printf(seq, "Boot delay       : ");
 692         if (nvram[10] == 0)
 693                 seq_printf(seq, "default");
 694         else
 695                 seq_printf(seq, "%ds%s\n", nvram[10],
 696                     nvram[10] < 8 ? ", no memory test" : "");
 697
 698         vmode = (nvram[14] << 8) || nvram[15];
 699         seq_printf(seq,
 700             "Video mode       : %s colors, %d columns, %s %s monitor\n",
 701             colors[vmode & 7],
 702             vmode & 8 ? 80 : 40,
 703             vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
 704         seq_printf(seq, "                   %soverscan, compat. mode %s%s\n",
 705             vmode & 64 ? "" : "no ",
 706             vmode & 128 ? "on" : "off",
 707             vmode & 256 ?
 708             (vmode & 16 ? ", line doubling" : ", half screen") : "");
 709
 710         return;
 711 }
 712 #endif
 713
 714 #endif /* MACH == ATARI */
 715
 716 MODULE_LICENSE("GPL");
 717 MODULE_ALIAS_MISCDEV(NVRAM_MINOR);