aboutsummaryrefslogtreecommitdiff
path: root/drivers/char/nvram.c
blob: 66d2917b003f6361080e063323d88dca49fd623f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
/*
 * CMOS/NV-RAM driver for Linux
 *
 * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
 * idea by and with help from Richard Jelinek <rj@suse.de>
 * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com)
 *
 * This driver allows you to access the contents of the non-volatile memory in
 * the mc146818rtc.h real-time clock. This chip is built into all PCs and into
 * many Atari machines. In the former it's called "CMOS-RAM", in the latter
 * "NVRAM" (NV stands for non-volatile).
 *
 * The data are supplied as a (seekable) character device, /dev/nvram. The
 * size of this file is dependent on the controller.  The usual size is 114,
 * the number of freely available bytes in the memory (i.e., not used by the
 * RTC itself).
 *
 * Checksums over the NVRAM contents are managed by this driver. In case of a
 * bad checksum, reads and writes return -EIO. The checksum can be initialized
 * to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or
 * ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid
 * again; use with care!)
 *
 * This file also provides some functions for other parts of the kernel that
 * want to access the NVRAM: nvram_{read,write,check_checksum,set_checksum}.
 * Obviously this can be used only if this driver is always configured into
 * the kernel and is not a module. Since the functions are used by some Atari
 * drivers, this is the case on the Atari.
 *
 *
 * 	1.1	Cesar Barros: SMP locking fixes
 * 		added changelog
 * 	1.2	Erik Gilling: Cobalt Networks support
 * 		Tim Hockin: general cleanup, Cobalt support
 * 	1.3	Wim Van Sebroeck: convert PRINT_PROC to seq_file
 */

#define NVRAM_VERSION	"1.3"

#include <linux/module.h>
#include <linux/nvram.h>

#define PC		1
#define ATARI		2

/* select machine configuration */
#if defined(CONFIG_ATARI)
#  define MACH ATARI
#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)  /* and ?? */
#  define MACH PC
#else
#  error Cannot build nvram driver for this machine configuration.
#endif

#if MACH == PC

/* RTC in a PC */
#define CHECK_DRIVER_INIT()	1

/* On PCs, the checksum is built only over bytes 2..31 */
#define PC_CKS_RANGE_START	2
#define PC_CKS_RANGE_END	31
#define PC_CKS_LOC		32
#define NVRAM_BYTES		(128-NVRAM_FIRST_BYTE)

#define mach_check_checksum	pc_check_checksum
#define mach_set_checksum	pc_set_checksum
#define mach_proc_infos		pc_proc_infos

#endif

#if MACH == ATARI

/* Special parameters for RTC in Atari machines */
#include <asm/atarihw.h>
#include <asm/atariints.h>
#define RTC_PORT(x)		(TT_RTC_BAS + 2*(x))
#define CHECK_DRIVER_INIT()	(MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))

#define NVRAM_BYTES		50

/* On Ataris, the checksum is over all bytes except the checksum bytes
 * themselves; these are at the very end */
#define ATARI_CKS_RANGE_START	0
#define ATARI_CKS_RANGE_END	47
#define ATARI_CKS_LOC		48

#define mach_check_checksum	atari_check_checksum
#define mach_set_checksum	atari_set_checksum
#define mach_proc_infos		atari_proc_infos

#endif

/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
 * rtc_lock held. Due to the index-port/data-port design of the RTC, we
 * don't want two different things trying to get to it at once. (e.g. the
 * periodic 11 min sync from time.c vs. this driver.)
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/mc146818rtc.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/smp_lock.h>

#include <asm/system.h>

static DEFINE_SPINLOCK(nvram_state_lock);
static int nvram_open_cnt;	/* #times opened */
static int nvram_open_mode;	/* special open modes */
#define NVRAM_WRITE		1 /* opened for writing (exclusive) */
#define NVRAM_EXCL		2 /* opened with O_EXCL */

static int mach_check_checksum(void);
static void mach_set_checksum(void);

#ifdef CONFIG_PROC_FS
static void mach_proc_infos(unsigned char *contents, struct seq_file *seq,
								void *offset);
#endif

/*
 * These functions are provided to be called internally or by other parts of
 * the kernel. It's up to the caller to ensure correct checksum before reading
 * or after writing (needs to be done only once).
 *
 * It is worth noting that these functions all access bytes of general
 * purpose memory in the NVRAM - that is to say, they all add the
 * NVRAM_FIRST_BYTE offset.  Pass them offsets into NVRAM as if you did not
 * know about the RTC cruft.
 */

unsigned char __nvram_read_byte(int i)
{
	return CMOS_READ(NVRAM_FIRST_BYTE + i);
}
EXPORT_SYMBOL(__nvram_read_byte);

unsigned char nvram_read_byte(int i)
{
	unsigned long flags;
	unsigned char c;

	spin_lock_irqsave(&rtc_lock, flags);
	c = __nvram_read_byte(i);
	spin_unlock_irqrestore(&rtc_lock, flags);
	return c;
}
EXPORT_SYMBOL(nvram_read_byte);

/* This races nicely with trying to read with checksum checking (nvram_read) */
void __nvram_write_byte(unsigned char c, int i)
{
	CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
}
EXPORT_SYMBOL(__nvram_write_byte);

void nvram_write_byte(unsigned char c, int i)
{
	unsigned long flags;

	spin_lock_irqsave(&rtc_lock, flags);
	__nvram_write_byte(c, i);
	spin_unlock_irqrestore(&rtc_lock, flags);
}
EXPORT_SYMBOL(nvram_write_byte);

int __nvram_check_checksum(void)
{
	return mach_check_checksum();
}
EXPORT_SYMBOL(__nvram_check_checksum);

int nvram_check_checksum(void)
{
	unsigned long flags;
	int rv;

	spin_lock_irqsave(&rtc_lock, flags);
	rv = __nvram_check_checksum();
	spin_unlock_irqrestore(&rtc_lock, flags);
	return rv;
}
EXPORT_SYMBOL(nvram_check_checksum);

static void __nvram_set_checksum(void)
{
	mach_set_checksum();
}

#if 0
void nvram_set_checksum(void)
{
	unsigned long flags;

	spin_lock_irqsave(&rtc_lock, flags);
	__nvram_set_checksum();
	spin_unlock_irqrestore(&rtc_lock, flags);
}
#endif  /*  0  */

/*
 * The are the file operation function for user access to /dev/nvram
 */

static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
{
	switch (origin) {
	case 0:
		/* nothing to do */
		break;
	case 1:
		offset += file->f_pos;
		break;
	case 2:
		offset += NVRAM_BYTES;
		break;
	}

	return (offset >= 0) ? (file->f_pos = offset) : -EINVAL;
}

static ssize_t nvram_read(struct file *file, char __user *buf,
						size_t count, loff_t *ppos)
{
	unsigned char contents[NVRAM_BYTES];
	unsigned i = *ppos;
	unsigned char *tmp;

	spin_lock_irq(&rtc_lock);

	if (!__nvram_check_checksum())
		goto checksum_err;

	for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
		*tmp = __nvram_read_byte(i);

	spin_unlock_irq(&rtc_lock);

	if (copy_to_user(buf, contents, tmp - contents))
		return -EFAULT;

	*ppos = i;

	return tmp - contents;

checksum_err:
	spin_unlock_irq(&rtc_lock);
	return -EIO;
}

static ssize_t nvram_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	unsigned char contents[NVRAM_BYTES];
	unsigned i = *ppos;
	unsigned char *tmp;

	if (i >= NVRAM_BYTES)
		return 0;	/* Past EOF */

	if (count > NVRAM_BYTES - i)
		count = NVRAM_BYTES - i;
	if (count > NVRAM_BYTES)
		return -EFAULT;	/* Can't happen, but prove it to gcc */

	if (copy_from_user(contents, buf, count))
		return -EFAULT;

	spin_lock_irq(&rtc_lock);

	if (!__nvram_check_checksum())
		goto checksum_err;

	for (tmp = contents; count--; ++i, ++tmp)
		__nvram_write_byte(*tmp, i);

	__nvram_set_checksum();

	spin_unlock_irq(&rtc_lock);

	*ppos = i;

	return tmp - contents;

checksum_err:
	spin_unlock_irq(&rtc_lock);
	return -EIO;
}

static long nvram_ioctl(struct file *file, unsigned int cmd,
			unsigned long arg)
{
	int i;

	switch (cmd) {

	case NVRAM_INIT:
		/* initialize NVRAM contents and checksum */
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;

		lock_kernel();
		spin_lock_irq(&rtc_lock);

		for (i = 0; i < NVRAM_BYTES; ++i)
			__nvram_write_byte(0, i);
		__nvram_set_checksum();

		spin_unlock_irq(&rtc_lock);
		unlock_kernel();
		return 0;

	case NVRAM_SETCKS:
		/* just set checksum, contents unchanged (maybe useful after
		 * checksum garbaged somehow...) */
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;

		lock_kernel();
		spin_lock_irq(&rtc_lock);
		__nvram_set_checksum();
		spin_unlock_irq(&rtc_lock);
		unlock_kernel();
		return 0;

	default:
		return -ENOTTY;
	}
}

static int nvram_open(struct inode *inode, struct file *file)
{
	spin_lock(&nvram_state_lock);

	if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
	    (nvram_open_mode & NVRAM_EXCL) ||
	    ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
		spin_unlock(&nvram_state_lock);
		return -EBUSY;
	}

	if (file->f_flags & O_EXCL)
		nvram_open_mode |= NVRAM_EXCL;
	if (file->f_mode & FMODE_WRITE)
		nvram_open_mode |= NVRAM_WRITE;
	nvram_open_cnt++;

	spin_unlock(&nvram_state_lock);

	return 0;
}

static int nvram_release(struct inode *inode, struct file *file)
{
	spin_lock(&nvram_state_lock);

	nvram_open_cnt--;

	/* if only one instance is open, clear the EXCL bit */
	if (nvram_open_mode & NVRAM_EXCL)
		nvram_open_mode &= ~NVRAM_EXCL;
	if (file->f_mode & FMODE_WRITE)
		nvram_open_mode &= ~NVRAM_WRITE;

	spin_unlock(&nvram_state_lock);

	return 0;
}

#ifndef CONFIG_PROC_FS
static int nvram_add_proc_fs(void)
{
	return 0;
}

#else

static int nvram_proc_read(struct seq_file *seq, void *offset)
{
	unsigned char contents[NVRAM_BYTES];
	int i = 0;

	spin_lock_irq(&rtc_lock);
	for (i = 0; i < NVRAM_BYTES; ++i)
		contents[i] = __nvram_read_byte(i);
	spin_unlock_irq(&rtc_lock);

	mach_proc_infos(contents, seq, offset);

	return 0;
}

static int nvram_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, nvram_proc_read, NULL);
}

static const struct file_operations nvram_proc_fops = {
	.owner		= THIS_MODULE,
	.open		= nvram_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int nvram_add_proc_fs(void)
{
	if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops))
		return -ENOMEM;
	return 0;
}

#endif /* CONFIG_PROC_FS */

static const struct file_operations nvram_fops = {
	.owner		= THIS_MODULE,
	.llseek		= nvram_llseek,
	.read		= nvram_read,
	.write		= nvram_write,
	.unlocked_ioctl	= nvram_ioctl,
	.open		= nvram_open,
	.release	= nvram_release,
};

static struct miscdevice nvram_dev = {
	NVRAM_MINOR,
	"nvram",
	&nvram_fops
};

static int __init nvram_init(void)
{
	int ret;

	/* First test whether the driver should init at all */
	if (!CHECK_DRIVER_INIT())
		return -ENODEV;

	ret = misc_register(&nvram_dev);
	if (ret) {
		printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
		    NVRAM_MINOR);
		goto out;
	}
	ret = nvram_add_proc_fs();
	if (ret) {
		printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n");
		goto outmisc;
	}
	ret = 0;
	printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n");
out:
	return ret;
outmisc:
	misc_deregister(&nvram_dev);
	goto out;
}

static void __exit nvram_cleanup_module(void)
{
	remove_proc_entry("driver/nvram", NULL);
	misc_deregister(&nvram_dev);
}

module_init(nvram_init);
module_exit(nvram_cleanup_module);

/*
 * Machine specific functions
 */

#if MACH == PC

static int pc_check_checksum(void)
{
	int i;
	unsigned short sum = 0;
	unsigned short expect;

	for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
		sum += __nvram_read_byte(i);
	expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
	    __nvram_read_byte(PC_CKS_LOC+1);
	return (sum & 0xffff) == expect;
}

static void pc_set_checksum(void)
{
	int i;
	unsigned short sum = 0;

	for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
		sum += __nvram_read_byte(i);
	__nvram_write_byte(sum >> 8, PC_CKS_LOC);
	__nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
}

#ifdef CONFIG_PROC_FS

static char *floppy_types[] = {
	"none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M",
	"3.5'' 2.88M", "3.5'' 2.88M"
};

static char *gfx_types[] = {
	"EGA, VGA, ... (with BIOS)",
	"CGA (40 cols)",
	"CGA (80 cols)",
	"monochrome",
};

static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq,
								void *offset)
{
	int checksum;
	int type;

	spin_lock_irq(&rtc_lock);
	checksum = __nvram_check_checksum();
	spin_unlock_irq(&rtc_lock);

	seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not ");

	seq_printf(seq, "# floppies     : %d\n",
	    (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0);
	seq_printf(seq, "Floppy 0 type  : ");
	type = nvram[2] >> 4;
	if (type < ARRAY_SIZE(floppy_types))
		seq_printf(seq, "%s\n", floppy_types[type]);
	else
		seq_printf(seq, "%d (unknown)\n", type);
	seq_printf(seq, "Floppy 1 type  : ");
	type = nvram[2] & 0x0f;
	if (type < ARRAY_SIZE(floppy_types))
		seq_printf(seq, "%s\n", floppy_types[type]);
	else
		seq_printf(seq, "%d (unknown)\n", type);

	seq_printf(seq, "HD 0 type      : ");
	type = nvram[4] >> 4;
	if (type)
		seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type);
	else
		seq_printf(seq, "none\n");

	seq_printf(seq, "HD 1 type      : ");
	type = nvram[4] & 0x0f;
	if (type)
		seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type);
	else
		seq_printf(seq, "none\n");

	seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
	    nvram[18] | (nvram[19] << 8),
	    nvram[20], nvram[25],
	    nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8));
	seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
	    nvram[39] | (nvram[40] << 8),
	    nvram[41], nvram[46],
	    nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8));

	seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8));
	seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n",
	    nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8));

	seq_printf(seq, "Gfx adapter    : %s\n",
	    gfx_types[(nvram[6] >> 4) & 3]);

	seq_printf(seq, "FPU            : %sinstalled\n",
	    (nvram[6] & 2) ? "" : "not ");

	return;
}
#endif

#endif /* MACH == PC */

#if MACH == ATARI

static int atari_check_checksum(void)
{
	int i;
	unsigned char sum = 0;

	for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
		sum += __nvram_read_byte(i);
	return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
	    (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
}

static void atari_set_checksum(void)
{
	int i;
	unsigned char sum = 0;

	for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
		sum += __nvram_read_byte(i);
	__nvram_write_byte(~sum, ATARI_CKS_LOC);
	__nvram_write_byte(sum, ATARI_CKS_LOC + 1);
}

#ifdef CONFIG_PROC_FS

static struct {
	unsigned char val;
	char *name;
} boot_prefs[] = {
	{ 0x80, "TOS" },
	{ 0x40, "ASV" },
	{ 0x20, "NetBSD (?)" },
	{ 0x10, "Linux" },
	{ 0x00, "unspecified" }
};

static char *languages[] = {
	"English (US)",
	"German",
	"French",
	"English (UK)",
	"Spanish",
	"Italian",
	"6 (undefined)",
	"Swiss (French)",
	"Swiss (German)"
};

static char *dateformat[] = {
	"MM%cDD%cYY",
	"DD%cMM%cYY",
	"YY%cMM%cDD",
	"YY%cDD%cMM",
	"4 (undefined)",
	"5 (undefined)",
	"6 (undefined)",
	"7 (undefined)"
};

static char *colors[] = {
	"2", "4", "16", "256", "65536", "??", "??", "??"
};

static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq,
								void *offset)
{
	int checksum = nvram_check_checksum();
	int i;
	unsigned vmode;

	seq_printf(seq, "Checksum status  : %svalid\n", checksum ? "" : "not ");

	seq_printf(seq, "Boot preference  : ");
	for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
		if (nvram[1] == boot_prefs[i].val) {
			seq_printf(seq, "%s\n", boot_prefs[i].name);
			break;
		}
	}
	if (i < 0)
		seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);

	seq_printf(seq, "SCSI arbitration : %s\n",
	    (nvram[16] & 0x80) ? "on" : "off");
	seq_printf(seq, "SCSI host ID     : ");
	if (nvram[16] & 0x80)
		seq_printf(seq, "%d\n", nvram[16] & 7);
	else
		seq_printf(seq, "n/a\n");

	/* the following entries are defined only for the Falcon */
	if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
		return;

	seq_printf(seq, "OS language      : ");
	if (nvram[6] < ARRAY_SIZE(languages))
		seq_printf(seq, "%s\n", languages[nvram[6]]);
	else
		seq_printf(seq, "%u (undefined)\n", nvram[6]);
	seq_printf(seq, "Keyboard language: ");
	if (nvram[7] < ARRAY_SIZE(languages))
		seq_printf(seq, "%s\n", languages[nvram[7]]);
	else
		seq_printf(seq, "%u (undefined)\n", nvram[7]);
	seq_printf(seq, "Date format      : ");
	seq_printf(seq, dateformat[nvram[8] & 7],
	    nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
	seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
	seq_printf(seq, "Boot delay       : ");
	if (nvram[10] == 0)
		seq_printf(seq, "default");
	else
		seq_printf(seq, "%ds%s\n", nvram[10],
		    nvram[10] < 8 ? ", no memory test" : "");

	vmode = (nvram[14] << 8) || nvram[15];
	seq_printf(seq,
	    "Video mode       : %s colors, %d columns, %s %s monitor\n",
	    colors[vmode & 7],
	    vmode & 8 ? 80 : 40,
	    vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
	seq_printf(seq, "                   %soverscan, compat. mode %s%s\n",
	    vmode & 64 ? "" : "no ",
	    vmode & 128 ? "on" : "off",
	    vmode & 256 ?
	    (vmode & 16 ? ", line doubling" : ", half screen") : "");

	return;
}
#endif

#endif /* MACH == ATARI */

MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(NVRAM_MINOR);