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/nvram.h>
  42
  43 #define PC              1
  44 #define ATARI           2
  45
  46 /* select machine configuration */
  47 #if defined(CONFIG_ATARI)
  48 #  define MACH ATARI
  49 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)  /* and ?? */
  50 #  define MACH PC
  51 #else
  52 #  error Cannot build nvram driver for this machine configuration.
  53 #endif
  54
  55 #if MACH == PC
  56
  57 /* RTC in a PC */
  58 #define CHECK_DRIVER_INIT()     1
  59
  60 /* On PCs, the checksum is built only over bytes 2..31 */
  61 #define PC_CKS_RANGE_START      2
  62 #define PC_CKS_RANGE_END        31
  63 #define PC_CKS_LOC              32
  64 #define NVRAM_BYTES             (128-NVRAM_FIRST_BYTE)
  65
  66 #define mach_check_checksum     pc_check_checksum
  67 #define mach_set_checksum       pc_set_checksum
  68 #define mach_proc_infos         pc_proc_infos
  69
  70 #endif
  71
  72 #if MACH == ATARI
  73
  74 /* Special parameters for RTC in Atari machines */
  75 #include <asm/atarihw.h>
  76 #include <asm/atariints.h>
  77 #define RTC_PORT(x)             (TT_RTC_BAS + 2*(x))
  78 #define CHECK_DRIVER_INIT()     (MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))
  79
  80 #define NVRAM_BYTES             50
  81
  82 /* On Ataris, the checksum is over all bytes except the checksum bytes
  83  * themselves; these are at the very end */
  84 #define ATARI_CKS_RANGE_START   0
  85 #define ATARI_CKS_RANGE_END     47
  86 #define ATARI_CKS_LOC           48
  87
  88 #define mach_check_checksum     atari_check_checksum
  89 #define mach_set_checksum       atari_set_checksum
  90 #define mach_proc_infos         atari_proc_infos
  91
  92 #endif
  93
  94 /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
  95  * rtc_lock held. Due to the index-port/data-port design of the RTC, we
  96  * don't want two different things trying to get to it at once. (e.g. the
  97  * periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
  98  */
  99
 100 #include <linux/types.h>
 101 #include <linux/errno.h>
 102 #include <linux/miscdevice.h>
 103 #include <linux/ioport.h>
 104 #include <linux/fcntl.h>
 105 #include <linux/mc146818rtc.h>
 106 #include <linux/init.h>
 107 #include <linux/proc_fs.h>
 108 #include <linux/seq_file.h>
 109 #include <linux/spinlock.h>
 110 #include <linux/io.h>
 111 #include <linux/uaccess.h>
 112 #include <linux/mutex.h>
 113 #include <linux/pagemap.h>
 114
 115
 116 static DEFINE_MUTEX(nvram_mutex);
 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         return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
 218                                         NVRAM_BYTES);
 219 }
 220
 221 static ssize_t nvram_read(struct file *file, char __user *buf,
 222                                                 size_t count, loff_t *ppos)
 223 {
 224         unsigned char contents[NVRAM_BYTES];
 225         unsigned i = *ppos;
 226         unsigned char *tmp;
 227
 228         spin_lock_irq(&rtc_lock);
 229
 230         if (!__nvram_check_checksum())
 231                 goto checksum_err;
 232
 233         for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
 234                 *tmp = __nvram_read_byte(i);
 235
 236         spin_unlock_irq(&rtc_lock);
 237
 238         if (copy_to_user(buf, contents, tmp - contents))
 239                 return -EFAULT;
 240
 241         *ppos = i;
 242
 243         return tmp - contents;
 244
 245 checksum_err:
 246         spin_unlock_irq(&rtc_lock);
 247         return -EIO;
 248 }
 249
 250 static ssize_t nvram_write(struct file *file, const char __user *buf,
 251                                                 size_t count, loff_t *ppos)
 252 {
 253         unsigned char contents[NVRAM_BYTES];
 254         unsigned i = *ppos;
 255         unsigned char *tmp;
 256
 257         if (i >= NVRAM_BYTES)
 258                 return 0;       /* Past EOF */
 259
 260         if (count > NVRAM_BYTES - i)
 261                 count = NVRAM_BYTES - i;
 262         if (count > NVRAM_BYTES)
 263                 return -EFAULT; /* Can't happen, but prove it to gcc */
 264
 265         if (copy_from_user(contents, buf, count))
 266                 return -EFAULT;
 267
 268         spin_lock_irq(&rtc_lock);
 269
 270         if (!__nvram_check_checksum())
 271                 goto checksum_err;
 272
 273         for (tmp = contents; count--; ++i, ++tmp)
 274                 __nvram_write_byte(*tmp, i);
 275
 276         __nvram_set_checksum();
 277
 278         spin_unlock_irq(&rtc_lock);
 279
 280         *ppos = i;
 281
 282         return tmp - contents;
 283
 284 checksum_err:
 285         spin_unlock_irq(&rtc_lock);
 286         return -EIO;
 287 }
 288
 289 static long nvram_ioctl(struct file *file, unsigned int cmd,
 290                         unsigned long arg)
 291 {
 292         int i;
 293
 294         switch (cmd) {
 295
 296         case NVRAM_INIT:
 297                 /* initialize NVRAM contents and checksum */
 298                 if (!capable(CAP_SYS_ADMIN))
 299                         return -EACCES;
 300
 301                 mutex_lock(&nvram_mutex);
 302                 spin_lock_irq(&rtc_lock);
 303
 304                 for (i = 0; i < NVRAM_BYTES; ++i)
 305                         __nvram_write_byte(0, i);
 306                 __nvram_set_checksum();
 307
 308                 spin_unlock_irq(&rtc_lock);
 309                 mutex_unlock(&nvram_mutex);
 310                 return 0;
 311
 312         case NVRAM_SETCKS:
 313                 /* just set checksum, contents unchanged (maybe useful after
 314                  * checksum garbaged somehow...) */
 315                 if (!capable(CAP_SYS_ADMIN))
 316                         return -EACCES;
 317
 318                 mutex_lock(&nvram_mutex);
 319                 spin_lock_irq(&rtc_lock);
 320                 __nvram_set_checksum();
 321                 spin_unlock_irq(&rtc_lock);
 322                 mutex_unlock(&nvram_mutex);
 323                 return 0;
 324
 325         default:
 326                 return -ENOTTY;
 327         }
 328 }
 329
 330 static int nvram_open(struct inode *inode, struct file *file)
 331 {
 332         spin_lock(&nvram_state_lock);
 333
 334         if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
 335             (nvram_open_mode & NVRAM_EXCL) ||
 336             ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
 337                 spin_unlock(&nvram_state_lock);
 338                 return -EBUSY;
 339         }
 340
 341         if (file->f_flags & O_EXCL)
 342                 nvram_open_mode |= NVRAM_EXCL;
 343         if (file->f_mode & FMODE_WRITE)
 344                 nvram_open_mode |= NVRAM_WRITE;
 345         nvram_open_cnt++;
 346
 347         spin_unlock(&nvram_state_lock);
 348
 349         return 0;
 350 }
 351
 352 static int nvram_release(struct inode *inode, struct file *file)
 353 {
 354         spin_lock(&nvram_state_lock);
 355
 356         nvram_open_cnt--;
 357
 358         /* if only one instance is open, clear the EXCL bit */
 359         if (nvram_open_mode & NVRAM_EXCL)
 360                 nvram_open_mode &= ~NVRAM_EXCL;
 361         if (file->f_mode & FMODE_WRITE)
 362                 nvram_open_mode &= ~NVRAM_WRITE;
 363
 364         spin_unlock(&nvram_state_lock);
 365
 366         return 0;
 367 }
 368
 369 #ifndef CONFIG_PROC_FS
 370 static int nvram_add_proc_fs(void)
 371 {
 372         return 0;
 373 }
 374
 375 #else
 376
 377 static int nvram_proc_read(struct seq_file *seq, void *offset)
 378 {
 379         unsigned char contents[NVRAM_BYTES];
 380         int i = 0;
 381
 382         spin_lock_irq(&rtc_lock);
 383         for (i = 0; i < NVRAM_BYTES; ++i)
 384                 contents[i] = __nvram_read_byte(i);
 385         spin_unlock_irq(&rtc_lock);
 386
 387         mach_proc_infos(contents, seq, offset);
 388
 389         return 0;
 390 }
 391
 392 static int nvram_proc_open(struct inode *inode, struct file *file)
 393 {
 394         return single_open(file, nvram_proc_read, NULL);
 395 }
 396
 397 static const struct file_operations nvram_proc_fops = {
 398         .owner          = THIS_MODULE,
 399         .open           = nvram_proc_open,
 400         .read           = seq_read,
 401         .llseek         = seq_lseek,
 402         .release        = single_release,
 403 };
 404
 405 static int nvram_add_proc_fs(void)
 406 {
 407         if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops))
 408                 return -ENOMEM;
 409         return 0;
 410 }
 411
 412 #endif /* CONFIG_PROC_FS */
 413
 414 static const struct file_operations nvram_fops = {
 415         .owner          = THIS_MODULE,
 416         .llseek         = nvram_llseek,
 417         .read           = nvram_read,
 418         .write          = nvram_write,
 419         .unlocked_ioctl = nvram_ioctl,
 420         .open           = nvram_open,
 421         .release        = nvram_release,
 422 };
 423
 424 static struct miscdevice nvram_dev = {
 425         NVRAM_MINOR,
 426         "nvram",
 427         &nvram_fops
 428 };
 429
 430 static int __init nvram_init(void)
 431 {
 432         int ret;
 433
 434         /* First test whether the driver should init at all */
 435         if (!CHECK_DRIVER_INIT())
 436                 return -ENODEV;
 437
 438         ret = misc_register(&nvram_dev);
 439         if (ret) {
 440                 printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
 441                     NVRAM_MINOR);
 442                 goto out;
 443         }
 444         ret = nvram_add_proc_fs();
 445         if (ret) {
 446                 printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n");
 447                 goto outmisc;
 448         }
 449         ret = 0;
 450         printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n");
 451 out:
 452         return ret;
 453 outmisc:
 454         misc_deregister(&nvram_dev);
 455         goto out;
 456 }
 457
 458 static void __exit nvram_cleanup_module(void)
 459 {
 460         remove_proc_entry("driver/nvram", NULL);
 461         misc_deregister(&nvram_dev);
 462 }
 463
 464 module_init(nvram_init);
 465 module_exit(nvram_cleanup_module);
 466
 467 /*
 468  * Machine specific functions
 469  */
 470
 471 #if MACH == PC
 472
 473 static int pc_check_checksum(void)
 474 {
 475         int i;
 476         unsigned short sum = 0;
 477         unsigned short expect;
 478
 479         for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
 480                 sum += __nvram_read_byte(i);
 481         expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
 482             __nvram_read_byte(PC_CKS_LOC+1);
 483         return (sum & 0xffff) == expect;
 484 }
 485
 486 static void pc_set_checksum(void)
 487 {
 488         int i;
 489         unsigned short sum = 0;
 490
 491         for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
 492                 sum += __nvram_read_byte(i);
 493         __nvram_write_byte(sum >> 8, PC_CKS_LOC);
 494         __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
 495 }
 496
 497 #ifdef CONFIG_PROC_FS
 498
 499 static const char * const floppy_types[] = {
 500         "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M",
 501         "3.5'' 2.88M", "3.5'' 2.88M"
 502 };
 503
 504 static const char * const gfx_types[] = {
 505         "EGA, VGA, ... (with BIOS)",
 506         "CGA (40 cols)",
 507         "CGA (80 cols)",
 508         "monochrome",
 509 };
 510
 511 static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq,
 512                                                                 void *offset)
 513 {
 514         int checksum;
 515         int type;
 516
 517         spin_lock_irq(&rtc_lock);
 518         checksum = __nvram_check_checksum();
 519         spin_unlock_irq(&rtc_lock);
 520
 521         seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not ");
 522
 523         seq_printf(seq, "# floppies     : %d\n",
 524             (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0);
 525         seq_printf(seq, "Floppy 0 type  : ");
 526         type = nvram[2] >> 4;
 527         if (type < ARRAY_SIZE(floppy_types))
 528                 seq_printf(seq, "%s\n", floppy_types[type]);
 529         else
 530                 seq_printf(seq, "%d (unknown)\n", type);
 531         seq_printf(seq, "Floppy 1 type  : ");
 532         type = nvram[2] & 0x0f;
 533         if (type < ARRAY_SIZE(floppy_types))
 534                 seq_printf(seq, "%s\n", floppy_types[type]);
 535         else
 536                 seq_printf(seq, "%d (unknown)\n", type);
 537
 538         seq_printf(seq, "HD 0 type      : ");
 539         type = nvram[4] >> 4;
 540         if (type)
 541                 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type);
 542         else
 543                 seq_printf(seq, "none\n");
 544
 545         seq_printf(seq, "HD 1 type      : ");
 546         type = nvram[4] & 0x0f;
 547         if (type)
 548                 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type);
 549         else
 550                 seq_printf(seq, "none\n");
 551
 552         seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
 553             nvram[18] | (nvram[19] << 8),
 554             nvram[20], nvram[25],
 555             nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8));
 556         seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
 557             nvram[39] | (nvram[40] << 8),
 558             nvram[41], nvram[46],
 559             nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8));
 560
 561         seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8));
 562         seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n",
 563             nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8));
 564
 565         seq_printf(seq, "Gfx adapter    : %s\n",
 566             gfx_types[(nvram[6] >> 4) & 3]);
 567
 568         seq_printf(seq, "FPU            : %sinstalled\n",
 569             (nvram[6] & 2) ? "" : "not ");
 570
 571         return;
 572 }
 573 #endif
 574
 575 #endif /* MACH == PC */
 576
 577 #if MACH == ATARI
 578
 579 static int atari_check_checksum(void)
 580 {
 581         int i;
 582         unsigned char sum = 0;
 583
 584         for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
 585                 sum += __nvram_read_byte(i);
 586         return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
 587             (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
 588 }
 589
 590 static void atari_set_checksum(void)
 591 {
 592         int i;
 593         unsigned char sum = 0;
 594
 595         for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
 596                 sum += __nvram_read_byte(i);
 597         __nvram_write_byte(~sum, ATARI_CKS_LOC);
 598         __nvram_write_byte(sum, ATARI_CKS_LOC + 1);
 599 }
 600
 601 #ifdef CONFIG_PROC_FS
 602
 603 static struct {
 604         unsigned char val;
 605         const char *name;
 606 } boot_prefs[] = {
 607         { 0x80, "TOS" },
 608         { 0x40, "ASV" },
 609         { 0x20, "NetBSD (?)" },
 610         { 0x10, "Linux" },
 611         { 0x00, "unspecified" }
 612 };
 613
 614 static const char * const languages[] = {
 615         "English (US)",
 616         "German",
 617         "French",
 618         "English (UK)",
 619         "Spanish",
 620         "Italian",
 621         "6 (undefined)",
 622         "Swiss (French)",
 623         "Swiss (German)"
 624 };
 625
 626 static const char * const dateformat[] = {
 627         "MM%cDD%cYY",
 628         "DD%cMM%cYY",
 629         "YY%cMM%cDD",
 630         "YY%cDD%cMM",
 631         "4 (undefined)",
 632         "5 (undefined)",
 633         "6 (undefined)",
 634         "7 (undefined)"
 635 };
 636
 637 static const char * const colors[] = {
 638         "2", "4", "16", "256", "65536", "??", "??", "??"
 639 };
 640
 641 static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq,
 642                                                                 void *offset)
 643 {
 644         int checksum = nvram_check_checksum();
 645         int i;
 646         unsigned vmode;
 647
 648         seq_printf(seq, "Checksum status  : %svalid\n", checksum ? "" : "not ");
 649
 650         seq_printf(seq, "Boot preference  : ");
 651         for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
 652                 if (nvram[1] == boot_prefs[i].val) {
 653                         seq_printf(seq, "%s\n", boot_prefs[i].name);
 654                         break;
 655                 }
 656         }
 657         if (i < 0)
 658                 seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
 659
 660         seq_printf(seq, "SCSI arbitration : %s\n",
 661             (nvram[16] & 0x80) ? "on" : "off");
 662         seq_printf(seq, "SCSI host ID     : ");
 663         if (nvram[16] & 0x80)
 664                 seq_printf(seq, "%d\n", nvram[16] & 7);
 665         else
 666                 seq_printf(seq, "n/a\n");
 667
 668         /* the following entries are defined only for the Falcon */
 669         if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
 670                 return;
 671
 672         seq_printf(seq, "OS language      : ");
 673         if (nvram[6] < ARRAY_SIZE(languages))
 674                 seq_printf(seq, "%s\n", languages[nvram[6]]);
 675         else
 676                 seq_printf(seq, "%u (undefined)\n", nvram[6]);
 677         seq_printf(seq, "Keyboard language: ");
 678         if (nvram[7] < ARRAY_SIZE(languages))
 679                 seq_printf(seq, "%s\n", languages[nvram[7]]);
 680         else
 681                 seq_printf(seq, "%u (undefined)\n", nvram[7]);
 682         seq_printf(seq, "Date format      : ");
 683         seq_printf(seq, dateformat[nvram[8] & 7],
 684             nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
 685         seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
 686         seq_printf(seq, "Boot delay       : ");
 687         if (nvram[10] == 0)
 688                 seq_printf(seq, "default");
 689         else
 690                 seq_printf(seq, "%ds%s\n", nvram[10],
 691                     nvram[10] < 8 ? ", no memory test" : "");
 692
 693         vmode = (nvram[14] << 8) | nvram[15];
 694         seq_printf(seq,
 695             "Video mode       : %s colors, %d columns, %s %s monitor\n",
 696             colors[vmode & 7],
 697             vmode & 8 ? 80 : 40,
 698             vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
 699         seq_printf(seq, "                   %soverscan, compat. mode %s%s\n",
 700             vmode & 64 ? "" : "no ",
 701             vmode & 128 ? "on" : "off",
 702             vmode & 256 ?
 703             (vmode & 16 ? ", line doubling" : ", half screen") : "");
 704
 705         return;
 706 }
 707 #endif
 708
 709 #endif /* MACH == ATARI */
 710
 711 MODULE_LICENSE("GPL");
 712 MODULE_ALIAS_MISCDEV(NVRAM_MINOR);