xref: /openbmc/linux/drivers/char/nvram.c (revision 64c70b1c)
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  */
36 
37 #define NVRAM_VERSION	"1.2"
38 
39 #include <linux/module.h>
40 #include <linux/smp_lock.h>
41 #include <linux/nvram.h>
42 
43 #define PC		1
44 #define ATARI		2
45 #define COBALT		3
46 
47 /* select machine configuration */
48 #if defined(CONFIG_ATARI)
49 #  define MACH ATARI
50 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)  /* and others?? */
51 #define MACH PC
52 #  if defined(CONFIG_COBALT)
53 #    include <linux/cobalt-nvram.h>
54 #    define MACH COBALT
55 #  else
56 #    define MACH PC
57 #  endif
58 #else
59 #  error Cannot build nvram driver for this machine configuration.
60 #endif
61 
62 #if MACH == PC
63 
64 /* RTC in a PC */
65 #define CHECK_DRIVER_INIT()	1
66 
67 /* On PCs, the checksum is built only over bytes 2..31 */
68 #define PC_CKS_RANGE_START	2
69 #define PC_CKS_RANGE_END	31
70 #define PC_CKS_LOC		32
71 #define NVRAM_BYTES		(128-NVRAM_FIRST_BYTE)
72 
73 #define mach_check_checksum	pc_check_checksum
74 #define mach_set_checksum	pc_set_checksum
75 #define mach_proc_infos		pc_proc_infos
76 
77 #endif
78 
79 #if MACH == COBALT
80 
81 #define CHECK_DRIVER_INIT()     1
82 
83 #define NVRAM_BYTES		(128-NVRAM_FIRST_BYTE)
84 
85 #define mach_check_checksum	cobalt_check_checksum
86 #define mach_set_checksum	cobalt_set_checksum
87 #define mach_proc_infos		cobalt_proc_infos
88 
89 #endif
90 
91 #if MACH == ATARI
92 
93 /* Special parameters for RTC in Atari machines */
94 #include <asm/atarihw.h>
95 #include <asm/atariints.h>
96 #define RTC_PORT(x)		(TT_RTC_BAS + 2*(x))
97 #define CHECK_DRIVER_INIT()	(MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))
98 
99 #define NVRAM_BYTES		50
100 
101 /* On Ataris, the checksum is over all bytes except the checksum bytes
102  * themselves; these are at the very end */
103 #define ATARI_CKS_RANGE_START	0
104 #define ATARI_CKS_RANGE_END	47
105 #define ATARI_CKS_LOC		48
106 
107 #define mach_check_checksum	atari_check_checksum
108 #define mach_set_checksum	atari_set_checksum
109 #define mach_proc_infos		atari_proc_infos
110 
111 #endif
112 
113 /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
114  * rtc_lock held. Due to the index-port/data-port design of the RTC, we
115  * don't want two different things trying to get to it at once. (e.g. the
116  * periodic 11 min sync from time.c vs. this driver.)
117  */
118 
119 #include <linux/types.h>
120 #include <linux/errno.h>
121 #include <linux/miscdevice.h>
122 #include <linux/slab.h>
123 #include <linux/ioport.h>
124 #include <linux/fcntl.h>
125 #include <linux/mc146818rtc.h>
126 #include <linux/init.h>
127 #include <linux/proc_fs.h>
128 #include <linux/spinlock.h>
129 
130 #include <asm/io.h>
131 #include <asm/uaccess.h>
132 #include <asm/system.h>
133 
134 static DEFINE_SPINLOCK(nvram_state_lock);
135 static int nvram_open_cnt;	/* #times opened */
136 static int nvram_open_mode;	/* special open modes */
137 #define NVRAM_WRITE		1 /* opened for writing (exclusive) */
138 #define NVRAM_EXCL		2 /* opened with O_EXCL */
139 
140 static int mach_check_checksum(void);
141 static void mach_set_checksum(void);
142 
143 #ifdef CONFIG_PROC_FS
144 static int mach_proc_infos(unsigned char *contents, char *buffer, int *len,
145     off_t *begin, off_t offset, int size);
146 #endif
147 
148 /*
149  * These functions are provided to be called internally or by other parts of
150  * the kernel. It's up to the caller to ensure correct checksum before reading
151  * or after writing (needs to be done only once).
152  *
153  * It is worth noting that these functions all access bytes of general
154  * purpose memory in the NVRAM - that is to say, they all add the
155  * NVRAM_FIRST_BYTE offset.  Pass them offsets into NVRAM as if you did not
156  * know about the RTC cruft.
157  */
158 
159 unsigned char
160 __nvram_read_byte(int i)
161 {
162 	return CMOS_READ(NVRAM_FIRST_BYTE + i);
163 }
164 
165 unsigned char
166 nvram_read_byte(int i)
167 {
168 	unsigned long flags;
169 	unsigned char c;
170 
171 	spin_lock_irqsave(&rtc_lock, flags);
172 	c = __nvram_read_byte(i);
173 	spin_unlock_irqrestore(&rtc_lock, flags);
174 	return c;
175 }
176 
177 /* This races nicely with trying to read with checksum checking (nvram_read) */
178 void
179 __nvram_write_byte(unsigned char c, int i)
180 {
181 	CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
182 }
183 
184 void
185 nvram_write_byte(unsigned char c, int i)
186 {
187 	unsigned long flags;
188 
189 	spin_lock_irqsave(&rtc_lock, flags);
190 	__nvram_write_byte(c, i);
191 	spin_unlock_irqrestore(&rtc_lock, flags);
192 }
193 
194 int
195 __nvram_check_checksum(void)
196 {
197 	return mach_check_checksum();
198 }
199 
200 int
201 nvram_check_checksum(void)
202 {
203 	unsigned long flags;
204 	int rv;
205 
206 	spin_lock_irqsave(&rtc_lock, flags);
207 	rv = __nvram_check_checksum();
208 	spin_unlock_irqrestore(&rtc_lock, flags);
209 	return rv;
210 }
211 
212 static void
213 __nvram_set_checksum(void)
214 {
215 	mach_set_checksum();
216 }
217 
218 #if 0
219 void
220 nvram_set_checksum(void)
221 {
222 	unsigned long flags;
223 
224 	spin_lock_irqsave(&rtc_lock, flags);
225 	__nvram_set_checksum();
226 	spin_unlock_irqrestore(&rtc_lock, flags);
227 }
228 #endif  /*  0  */
229 
230 /*
231  * The are the file operation function for user access to /dev/nvram
232  */
233 
234 static loff_t nvram_llseek(struct file *file,loff_t offset, int origin )
235 {
236 	lock_kernel();
237 	switch (origin) {
238 	case 0:
239 		/* nothing to do */
240 		break;
241 	case 1:
242 		offset += file->f_pos;
243 		break;
244 	case 2:
245 		offset += NVRAM_BYTES;
246 		break;
247 	}
248 	unlock_kernel();
249 	return (offset >= 0) ? (file->f_pos = offset) : -EINVAL;
250 }
251 
252 static ssize_t
253 nvram_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
254 {
255 	unsigned char contents[NVRAM_BYTES];
256 	unsigned i = *ppos;
257 	unsigned char *tmp;
258 
259 	spin_lock_irq(&rtc_lock);
260 
261 	if (!__nvram_check_checksum())
262 		goto checksum_err;
263 
264 	for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
265 		*tmp = __nvram_read_byte(i);
266 
267 	spin_unlock_irq(&rtc_lock);
268 
269 	if (copy_to_user(buf, contents, tmp - contents))
270 		return -EFAULT;
271 
272 	*ppos = i;
273 
274 	return tmp - contents;
275 
276       checksum_err:
277 	spin_unlock_irq(&rtc_lock);
278 	return -EIO;
279 }
280 
281 static ssize_t
282 nvram_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
283 {
284 	unsigned char contents[NVRAM_BYTES];
285 	unsigned i = *ppos;
286 	unsigned char *tmp;
287 	int len;
288 
289 	len = (NVRAM_BYTES - i) < count ? (NVRAM_BYTES - i) : count;
290 	if (copy_from_user(contents, buf, len))
291 		return -EFAULT;
292 
293 	spin_lock_irq(&rtc_lock);
294 
295 	if (!__nvram_check_checksum())
296 		goto checksum_err;
297 
298 	for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
299 		__nvram_write_byte(*tmp, i);
300 
301 	__nvram_set_checksum();
302 
303 	spin_unlock_irq(&rtc_lock);
304 
305 	*ppos = i;
306 
307 	return tmp - contents;
308 
309       checksum_err:
310 	spin_unlock_irq(&rtc_lock);
311 	return -EIO;
312 }
313 
314 static int
315 nvram_ioctl(struct inode *inode, struct file *file,
316     unsigned int cmd, unsigned long arg)
317 {
318 	int i;
319 
320 	switch (cmd) {
321 
322 	case NVRAM_INIT:
323 		/* initialize NVRAM contents and checksum */
324 		if (!capable(CAP_SYS_ADMIN))
325 			return -EACCES;
326 
327 		spin_lock_irq(&rtc_lock);
328 
329 		for (i = 0; i < NVRAM_BYTES; ++i)
330 			__nvram_write_byte(0, i);
331 		__nvram_set_checksum();
332 
333 		spin_unlock_irq(&rtc_lock);
334 		return 0;
335 
336 	case NVRAM_SETCKS:
337 		/* just set checksum, contents unchanged (maybe useful after
338 		 * checksum garbaged somehow...) */
339 		if (!capable(CAP_SYS_ADMIN))
340 			return -EACCES;
341 
342 		spin_lock_irq(&rtc_lock);
343 		__nvram_set_checksum();
344 		spin_unlock_irq(&rtc_lock);
345 		return 0;
346 
347 	default:
348 		return -ENOTTY;
349 	}
350 }
351 
352 static int
353 nvram_open(struct inode *inode, struct file *file)
354 {
355 	spin_lock(&nvram_state_lock);
356 
357 	if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
358 	    (nvram_open_mode & NVRAM_EXCL) ||
359 	    ((file->f_mode & 2) && (nvram_open_mode & NVRAM_WRITE))) {
360 		spin_unlock(&nvram_state_lock);
361 		return -EBUSY;
362 	}
363 
364 	if (file->f_flags & O_EXCL)
365 		nvram_open_mode |= NVRAM_EXCL;
366 	if (file->f_mode & 2)
367 		nvram_open_mode |= NVRAM_WRITE;
368 	nvram_open_cnt++;
369 
370 	spin_unlock(&nvram_state_lock);
371 
372 	return 0;
373 }
374 
375 static int
376 nvram_release(struct inode *inode, struct file *file)
377 {
378 	spin_lock(&nvram_state_lock);
379 
380 	nvram_open_cnt--;
381 
382 	/* if only one instance is open, clear the EXCL bit */
383 	if (nvram_open_mode & NVRAM_EXCL)
384 		nvram_open_mode &= ~NVRAM_EXCL;
385 	if (file->f_mode & 2)
386 		nvram_open_mode &= ~NVRAM_WRITE;
387 
388 	spin_unlock(&nvram_state_lock);
389 
390 	return 0;
391 }
392 
393 #ifndef CONFIG_PROC_FS
394 static int
395 nvram_read_proc(char *buffer, char **start, off_t offset,
396     int size, int *eof, void *data)
397 {
398 	return 0;
399 }
400 #else
401 
402 static int
403 nvram_read_proc(char *buffer, char **start, off_t offset,
404     int size, int *eof, void *data)
405 {
406 	unsigned char contents[NVRAM_BYTES];
407 	int i, len = 0;
408 	off_t begin = 0;
409 
410 	spin_lock_irq(&rtc_lock);
411 	for (i = 0; i < NVRAM_BYTES; ++i)
412 		contents[i] = __nvram_read_byte(i);
413 	spin_unlock_irq(&rtc_lock);
414 
415 	*eof = mach_proc_infos(contents, buffer, &len, &begin, offset, size);
416 
417 	if (offset >= begin + len)
418 		return 0;
419 	*start = buffer + (offset - begin);
420 	return (size < begin + len - offset) ? size : begin + len - offset;
421 
422 }
423 
424 /* This macro frees the machine specific function from bounds checking and
425  * this like that... */
426 #define PRINT_PROC(fmt,args...)					\
427 	do {							\
428 		*len += sprintf(buffer+*len, fmt, ##args);	\
429 		if (*begin + *len > offset + size)		\
430 			return 0;				\
431 		if (*begin + *len < offset) {			\
432 			*begin += *len;				\
433 			*len = 0;				\
434 		}						\
435 	} while(0)
436 
437 #endif /* CONFIG_PROC_FS */
438 
439 static const struct file_operations nvram_fops = {
440 	.owner		= THIS_MODULE,
441 	.llseek		= nvram_llseek,
442 	.read		= nvram_read,
443 	.write		= nvram_write,
444 	.ioctl		= nvram_ioctl,
445 	.open		= nvram_open,
446 	.release	= nvram_release,
447 };
448 
449 static struct miscdevice nvram_dev = {
450 	NVRAM_MINOR,
451 	"nvram",
452 	&nvram_fops
453 };
454 
455 static int __init
456 nvram_init(void)
457 {
458 	int ret;
459 
460 	/* First test whether the driver should init at all */
461 	if (!CHECK_DRIVER_INIT())
462 		return -ENXIO;
463 
464 	ret = misc_register(&nvram_dev);
465 	if (ret) {
466 		printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
467 		    NVRAM_MINOR);
468 		goto out;
469 	}
470 	if (!create_proc_read_entry("driver/nvram", 0, NULL, nvram_read_proc,
471 		NULL)) {
472 		printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n");
473 		ret = -ENOMEM;
474 		goto outmisc;
475 	}
476 	ret = 0;
477 	printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n");
478       out:
479 	return ret;
480       outmisc:
481 	misc_deregister(&nvram_dev);
482 	goto out;
483 }
484 
485 static void __exit
486 nvram_cleanup_module(void)
487 {
488 	remove_proc_entry("driver/nvram", NULL);
489 	misc_deregister(&nvram_dev);
490 }
491 
492 module_init(nvram_init);
493 module_exit(nvram_cleanup_module);
494 
495 /*
496  * Machine specific functions
497  */
498 
499 #if MACH == PC
500 
501 static int
502 pc_check_checksum(void)
503 {
504 	int i;
505 	unsigned short sum = 0;
506 	unsigned short expect;
507 
508 	for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
509 		sum += __nvram_read_byte(i);
510 	expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
511 	    __nvram_read_byte(PC_CKS_LOC+1);
512 	return ((sum & 0xffff) == expect);
513 }
514 
515 static void
516 pc_set_checksum(void)
517 {
518 	int i;
519 	unsigned short sum = 0;
520 
521 	for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
522 		sum += __nvram_read_byte(i);
523 	__nvram_write_byte(sum >> 8, PC_CKS_LOC);
524 	__nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
525 }
526 
527 #ifdef CONFIG_PROC_FS
528 
529 static char *floppy_types[] = {
530 	"none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M",
531 	"3.5'' 2.88M", "3.5'' 2.88M"
532 };
533 
534 static char *gfx_types[] = {
535 	"EGA, VGA, ... (with BIOS)",
536 	"CGA (40 cols)",
537 	"CGA (80 cols)",
538 	"monochrome",
539 };
540 
541 static int
542 pc_proc_infos(unsigned char *nvram, char *buffer, int *len,
543     off_t *begin, off_t offset, int size)
544 {
545 	int checksum;
546 	int type;
547 
548 	spin_lock_irq(&rtc_lock);
549 	checksum = __nvram_check_checksum();
550 	spin_unlock_irq(&rtc_lock);
551 
552 	PRINT_PROC("Checksum status: %svalid\n", checksum ? "" : "not ");
553 
554 	PRINT_PROC("# floppies     : %d\n",
555 	    (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0);
556 	PRINT_PROC("Floppy 0 type  : ");
557 	type = nvram[2] >> 4;
558 	if (type < ARRAY_SIZE(floppy_types))
559 		PRINT_PROC("%s\n", floppy_types[type]);
560 	else
561 		PRINT_PROC("%d (unknown)\n", type);
562 	PRINT_PROC("Floppy 1 type  : ");
563 	type = nvram[2] & 0x0f;
564 	if (type < ARRAY_SIZE(floppy_types))
565 		PRINT_PROC("%s\n", floppy_types[type]);
566 	else
567 		PRINT_PROC("%d (unknown)\n", type);
568 
569 	PRINT_PROC("HD 0 type      : ");
570 	type = nvram[4] >> 4;
571 	if (type)
572 		PRINT_PROC("%02x\n", type == 0x0f ? nvram[11] : type);
573 	else
574 		PRINT_PROC("none\n");
575 
576 	PRINT_PROC("HD 1 type      : ");
577 	type = nvram[4] & 0x0f;
578 	if (type)
579 		PRINT_PROC("%02x\n", type == 0x0f ? nvram[12] : type);
580 	else
581 		PRINT_PROC("none\n");
582 
583 	PRINT_PROC("HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
584 	    nvram[18] | (nvram[19] << 8),
585 	    nvram[20], nvram[25],
586 	    nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8));
587 	PRINT_PROC("HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
588 	    nvram[39] | (nvram[40] << 8),
589 	    nvram[41], nvram[46],
590 	    nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8));
591 
592 	PRINT_PROC("DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8));
593 	PRINT_PROC("Extended memory: %d kB (configured), %d kB (tested)\n",
594 	    nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8));
595 
596 	PRINT_PROC("Gfx adapter    : %s\n", gfx_types[(nvram[6] >> 4) & 3]);
597 
598 	PRINT_PROC("FPU            : %sinstalled\n",
599 	    (nvram[6] & 2) ? "" : "not ");
600 
601 	return 1;
602 }
603 #endif
604 
605 #endif /* MACH == PC */
606 
607 #if MACH == COBALT
608 
609 /* the cobalt CMOS has a wider range of its checksum */
610 static int cobalt_check_checksum(void)
611 {
612 	int i;
613 	unsigned short sum = 0;
614 	unsigned short expect;
615 
616 	for (i = COBT_CMOS_CKS_START; i <= COBT_CMOS_CKS_END; ++i) {
617 		if ((i == COBT_CMOS_CHECKSUM) || (i == (COBT_CMOS_CHECKSUM+1)))
618 			continue;
619 
620 		sum += __nvram_read_byte(i);
621 	}
622 	expect = __nvram_read_byte(COBT_CMOS_CHECKSUM) << 8 |
623 	    __nvram_read_byte(COBT_CMOS_CHECKSUM+1);
624 	return ((sum & 0xffff) == expect);
625 }
626 
627 static void cobalt_set_checksum(void)
628 {
629 	int i;
630 	unsigned short sum = 0;
631 
632 	for (i = COBT_CMOS_CKS_START; i <= COBT_CMOS_CKS_END; ++i) {
633 		if ((i == COBT_CMOS_CHECKSUM) || (i == (COBT_CMOS_CHECKSUM+1)))
634 			continue;
635 
636 		sum += __nvram_read_byte(i);
637 	}
638 
639 	__nvram_write_byte(sum >> 8, COBT_CMOS_CHECKSUM);
640 	__nvram_write_byte(sum & 0xff, COBT_CMOS_CHECKSUM+1);
641 }
642 
643 #ifdef CONFIG_PROC_FS
644 
645 static int cobalt_proc_infos(unsigned char *nvram, char *buffer, int *len,
646 	off_t *begin, off_t offset, int size)
647 {
648 	int i;
649 	unsigned int checksum;
650 	unsigned int flags;
651 	char sernum[14];
652 	char *key = "cNoEbTaWlOtR!";
653 	unsigned char bto_csum;
654 
655 	spin_lock_irq(&rtc_lock);
656 	checksum = __nvram_check_checksum();
657 	spin_unlock_irq(&rtc_lock);
658 
659 	PRINT_PROC("Checksum status: %svalid\n", checksum ? "" : "not ");
660 
661 	flags = nvram[COBT_CMOS_FLAG_BYTE_0] << 8
662 	    | nvram[COBT_CMOS_FLAG_BYTE_1];
663 
664 	PRINT_PROC("Console: %s\n",
665 		flags & COBT_CMOS_CONSOLE_FLAG ?  "on": "off");
666 
667 	PRINT_PROC("Firmware Debug Messages: %s\n",
668 		flags & COBT_CMOS_DEBUG_FLAG ? "on": "off");
669 
670 	PRINT_PROC("Auto Prompt: %s\n",
671 		flags & COBT_CMOS_AUTO_PROMPT_FLAG ? "on": "off");
672 
673 	PRINT_PROC("Shutdown Status: %s\n",
674 		flags & COBT_CMOS_CLEAN_BOOT_FLAG ? "clean": "dirty");
675 
676 	PRINT_PROC("Hardware Probe: %s\n",
677 		flags & COBT_CMOS_HW_NOPROBE_FLAG ? "partial": "full");
678 
679 	PRINT_PROC("System Fault: %sdetected\n",
680 		flags & COBT_CMOS_SYSFAULT_FLAG ? "": "not ");
681 
682 	PRINT_PROC("Panic on OOPS: %s\n",
683 		flags & COBT_CMOS_OOPSPANIC_FLAG ? "yes": "no");
684 
685 	PRINT_PROC("Delayed Cache Initialization: %s\n",
686 		flags & COBT_CMOS_DELAY_CACHE_FLAG ? "yes": "no");
687 
688 	PRINT_PROC("Show Logo at Boot: %s\n",
689 		flags & COBT_CMOS_NOLOGO_FLAG ? "no": "yes");
690 
691 	PRINT_PROC("Boot Method: ");
692 	switch (nvram[COBT_CMOS_BOOT_METHOD]) {
693 	case COBT_CMOS_BOOT_METHOD_DISK:
694 		PRINT_PROC("disk\n");
695 		break;
696 
697 	case COBT_CMOS_BOOT_METHOD_ROM:
698 		PRINT_PROC("rom\n");
699 		break;
700 
701 	case COBT_CMOS_BOOT_METHOD_NET:
702 		PRINT_PROC("net\n");
703 		break;
704 
705 	default:
706 		PRINT_PROC("unknown\n");
707 		break;
708 	}
709 
710 	PRINT_PROC("Primary Boot Device: %d:%d\n",
711 		nvram[COBT_CMOS_BOOT_DEV0_MAJ],
712 		nvram[COBT_CMOS_BOOT_DEV0_MIN] );
713 	PRINT_PROC("Secondary Boot Device: %d:%d\n",
714 		nvram[COBT_CMOS_BOOT_DEV1_MAJ],
715 		nvram[COBT_CMOS_BOOT_DEV1_MIN] );
716 	PRINT_PROC("Tertiary Boot Device: %d:%d\n",
717 		nvram[COBT_CMOS_BOOT_DEV2_MAJ],
718 		nvram[COBT_CMOS_BOOT_DEV2_MIN] );
719 
720 	PRINT_PROC("Uptime: %d\n",
721 		nvram[COBT_CMOS_UPTIME_0] << 24 |
722 		nvram[COBT_CMOS_UPTIME_1] << 16 |
723 		nvram[COBT_CMOS_UPTIME_2] << 8  |
724 		nvram[COBT_CMOS_UPTIME_3]);
725 
726 	PRINT_PROC("Boot Count: %d\n",
727 		nvram[COBT_CMOS_BOOTCOUNT_0] << 24 |
728 		nvram[COBT_CMOS_BOOTCOUNT_1] << 16 |
729 		nvram[COBT_CMOS_BOOTCOUNT_2] << 8  |
730 		nvram[COBT_CMOS_BOOTCOUNT_3]);
731 
732 	/* 13 bytes of serial num */
733 	for (i=0 ; i<13 ; i++) {
734 		sernum[i] = nvram[COBT_CMOS_SYS_SERNUM_0 + i];
735 	}
736 	sernum[13] = '\0';
737 
738 	checksum = 0;
739 	for (i=0 ; i<13 ; i++) {
740 		checksum += sernum[i] ^ key[i];
741 	}
742 	checksum = ((checksum & 0x7f) ^ (0xd6)) & 0xff;
743 
744 	PRINT_PROC("Serial Number: %s", sernum);
745 	if (checksum != nvram[COBT_CMOS_SYS_SERNUM_CSUM]) {
746 		PRINT_PROC(" (invalid checksum)");
747 	}
748 	PRINT_PROC("\n");
749 
750 	PRINT_PROC("Rom Revison: %d.%d.%d\n", nvram[COBT_CMOS_ROM_REV_MAJ],
751 		nvram[COBT_CMOS_ROM_REV_MIN], nvram[COBT_CMOS_ROM_REV_REV]);
752 
753 	PRINT_PROC("BTO Server: %d.%d.%d.%d", nvram[COBT_CMOS_BTO_IP_0],
754 		nvram[COBT_CMOS_BTO_IP_1], nvram[COBT_CMOS_BTO_IP_2],
755 		nvram[COBT_CMOS_BTO_IP_3]);
756 	bto_csum = nvram[COBT_CMOS_BTO_IP_0] + nvram[COBT_CMOS_BTO_IP_1]
757 		+ nvram[COBT_CMOS_BTO_IP_2] + nvram[COBT_CMOS_BTO_IP_3];
758 	if (bto_csum != nvram[COBT_CMOS_BTO_IP_CSUM]) {
759 		PRINT_PROC(" (invalid checksum)");
760 	}
761 	PRINT_PROC("\n");
762 
763 	if (flags & COBT_CMOS_VERSION_FLAG
764 	 && nvram[COBT_CMOS_VERSION] >= COBT_CMOS_VER_BTOCODE) {
765 		PRINT_PROC("BTO Code: 0x%x\n",
766 			nvram[COBT_CMOS_BTO_CODE_0] << 24 |
767 			nvram[COBT_CMOS_BTO_CODE_1] << 16 |
768 			nvram[COBT_CMOS_BTO_CODE_2] << 8 |
769 			nvram[COBT_CMOS_BTO_CODE_3]);
770 	}
771 
772 	return 1;
773 }
774 #endif /* CONFIG_PROC_FS */
775 
776 #endif /* MACH == COBALT */
777 
778 #if MACH == ATARI
779 
780 static int
781 atari_check_checksum(void)
782 {
783 	int i;
784 	unsigned char sum = 0;
785 
786 	for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
787 		sum += __nvram_read_byte(i);
788 	return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff) &&
789 	    __nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
790 }
791 
792 static void
793 atari_set_checksum(void)
794 {
795 	int i;
796 	unsigned char sum = 0;
797 
798 	for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
799 		sum += __nvram_read_byte(i);
800 	__nvram_write_byte(~sum, ATARI_CKS_LOC);
801 	__nvram_write_byte(sum, ATARI_CKS_LOC + 1);
802 }
803 
804 #ifdef CONFIG_PROC_FS
805 
806 static struct {
807 	unsigned char val;
808 	char *name;
809 } boot_prefs[] = {
810 	{ 0x80, "TOS" },
811 	{ 0x40, "ASV" },
812 	{ 0x20, "NetBSD (?)" },
813 	{ 0x10, "Linux" },
814 	{ 0x00, "unspecified" }
815 };
816 
817 static char *languages[] = {
818 	"English (US)",
819 	"German",
820 	"French",
821 	"English (UK)",
822 	"Spanish",
823 	"Italian",
824 	"6 (undefined)",
825 	"Swiss (French)",
826 	"Swiss (German)"
827 };
828 
829 static char *dateformat[] = {
830 	"MM%cDD%cYY",
831 	"DD%cMM%cYY",
832 	"YY%cMM%cDD",
833 	"YY%cDD%cMM",
834 	"4 (undefined)",
835 	"5 (undefined)",
836 	"6 (undefined)",
837 	"7 (undefined)"
838 };
839 
840 static char *colors[] = {
841 	"2", "4", "16", "256", "65536", "??", "??", "??"
842 };
843 
844 static int
845 atari_proc_infos(unsigned char *nvram, char *buffer, int *len,
846     off_t *begin, off_t offset, int size)
847 {
848 	int checksum = nvram_check_checksum();
849 	int i;
850 	unsigned vmode;
851 
852 	PRINT_PROC("Checksum status  : %svalid\n", checksum ? "" : "not ");
853 
854 	PRINT_PROC("Boot preference  : ");
855 	for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
856 		if (nvram[1] == boot_prefs[i].val) {
857 			PRINT_PROC("%s\n", boot_prefs[i].name);
858 			break;
859 		}
860 	}
861 	if (i < 0)
862 		PRINT_PROC("0x%02x (undefined)\n", nvram[1]);
863 
864 	PRINT_PROC("SCSI arbitration : %s\n",
865 	    (nvram[16] & 0x80) ? "on" : "off");
866 	PRINT_PROC("SCSI host ID     : ");
867 	if (nvram[16] & 0x80)
868 		PRINT_PROC("%d\n", nvram[16] & 7);
869 	else
870 		PRINT_PROC("n/a\n");
871 
872 	/* the following entries are defined only for the Falcon */
873 	if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
874 		return 1;
875 
876 	PRINT_PROC("OS language      : ");
877 	if (nvram[6] < ARRAY_SIZE(languages))
878 		PRINT_PROC("%s\n", languages[nvram[6]]);
879 	else
880 		PRINT_PROC("%u (undefined)\n", nvram[6]);
881 	PRINT_PROC("Keyboard language: ");
882 	if (nvram[7] < ARRAY_SIZE(languages))
883 		PRINT_PROC("%s\n", languages[nvram[7]]);
884 	else
885 		PRINT_PROC("%u (undefined)\n", nvram[7]);
886 	PRINT_PROC("Date format      : ");
887 	PRINT_PROC(dateformat[nvram[8] & 7],
888 	    nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
889 	PRINT_PROC(", %dh clock\n", nvram[8] & 16 ? 24 : 12);
890 	PRINT_PROC("Boot delay       : ");
891 	if (nvram[10] == 0)
892 		PRINT_PROC("default");
893 	else
894 		PRINT_PROC("%ds%s\n", nvram[10],
895 		    nvram[10] < 8 ? ", no memory test" : "");
896 
897 	vmode = (nvram[14] << 8) || nvram[15];
898 	PRINT_PROC("Video mode       : %s colors, %d columns, %s %s monitor\n",
899 	    colors[vmode & 7],
900 	    vmode & 8 ? 80 : 40,
901 	    vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
902 	PRINT_PROC("                   %soverscan, compat. mode %s%s\n",
903 	    vmode & 64 ? "" : "no ",
904 	    vmode & 128 ? "on" : "off",
905 	    vmode & 256 ?
906 	    (vmode & 16 ? ", line doubling" : ", half screen") : "");
907 
908 	return 1;
909 }
910 #endif
911 
912 #endif /* MACH == ATARI */
913 
914 MODULE_LICENSE("GPL");
915 
916 EXPORT_SYMBOL(__nvram_read_byte);
917 EXPORT_SYMBOL(nvram_read_byte);
918 EXPORT_SYMBOL(__nvram_write_byte);
919 EXPORT_SYMBOL(nvram_write_byte);
920 EXPORT_SYMBOL(__nvram_check_checksum);
921 EXPORT_SYMBOL(nvram_check_checksum);
922 MODULE_ALIAS_MISCDEV(NVRAM_MINOR);
923