aboutsummaryrefslogtreecommitdiff
path: root/arch/cris/arch-v32/drivers/axisflashmap.c
blob: b34438e026be436d6c71632a250a23c187d9c6f7 (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
/*
 * Physical mapping layer for MTD using the Axis partitiontable format
 *
 * Copyright (c) 2001-2007 Axis Communications AB
 *
 * This file is under the GPL.
 *
 * First partition is always sector 0 regardless of if we find a partitiontable
 * or not. In the start of the next sector, there can be a partitiontable that
 * tells us what other partitions to define. If there isn't, we use a default
 * partition split defined below.
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>

#include <linux/mtd/concat.h>
#include <linux/mtd/map.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/mtdram.h>
#include <linux/mtd/partitions.h>

#include <linux/cramfs_fs.h>

#include <asm/axisflashmap.h>
#include <asm/mmu.h>

#define MEM_CSE0_SIZE (0x04000000)
#define MEM_CSE1_SIZE (0x04000000)

#define FLASH_UNCACHED_ADDR  KSEG_E
#define FLASH_CACHED_ADDR    KSEG_F

#define PAGESIZE (512)

#if CONFIG_ETRAX_FLASH_BUSWIDTH==1
#define flash_data __u8
#elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
#define flash_data __u16
#elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
#define flash_data __u32
#endif

/* From head.S */
extern unsigned long romfs_in_flash; /* 1 when romfs_start, _length in flash */
extern unsigned long romfs_start, romfs_length;
extern unsigned long nand_boot; /* 1 when booted from nand flash */

struct partition_name {
	char name[6];
};

/* The master mtd for the entire flash. */
struct mtd_info* axisflash_mtd = NULL;

/* Map driver functions. */

static map_word flash_read(struct map_info *map, unsigned long ofs)
{
	map_word tmp;
	tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
	return tmp;
}

static void flash_copy_from(struct map_info *map, void *to,
			    unsigned long from, ssize_t len)
{
	memcpy(to, (void *)(map->map_priv_1 + from), len);
}

static void flash_write(struct map_info *map, map_word d, unsigned long adr)
{
	*(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
}

/*
 * The map for chip select e0.
 *
 * We run into tricky coherence situations if we mix cached with uncached
 * accesses to we only use the uncached version here.
 *
 * The size field is the total size where the flash chips may be mapped on the
 * chip select. MTD probes should find all devices there and it does not matter
 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
 * probes will ignore them.
 *
 * The start address in map_priv_1 is in virtual memory so we cannot use
 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
 * address of cse0.
 */
static struct map_info map_cse0 = {
	.name = "cse0",
	.size = MEM_CSE0_SIZE,
	.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
	.read = flash_read,
	.copy_from = flash_copy_from,
	.write = flash_write,
	.map_priv_1 = FLASH_UNCACHED_ADDR
};

/*
 * The map for chip select e1.
 *
 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
 * address, but there isn't.
 */
static struct map_info map_cse1 = {
	.name = "cse1",
	.size = MEM_CSE1_SIZE,
	.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
	.read = flash_read,
	.copy_from = flash_copy_from,
	.write = flash_write,
	.map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
};

#define MAX_PARTITIONS			7
#ifdef CONFIG_ETRAX_NANDBOOT
#define NUM_DEFAULT_PARTITIONS		4
#define DEFAULT_ROOTFS_PARTITION_NO	2
#define DEFAULT_MEDIA_SIZE              0x2000000 /* 32 megs */
#else
#define NUM_DEFAULT_PARTITIONS		3
#define DEFAULT_ROOTFS_PARTITION_NO	(-1)
#define DEFAULT_MEDIA_SIZE              0x800000 /* 8 megs */
#endif

#if (MAX_PARTITIONS < NUM_DEFAULT_PARTITIONS)
#error MAX_PARTITIONS must be >= than NUM_DEFAULT_PARTITIONS
#endif

/* Initialize the ones normally used. */
static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
	{
		.name = "part0",
		.size = CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = 0
	},
	{
		.name = "part1",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part2",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part3",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part4",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part5",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part6",
		.size = 0,
		.offset = 0
	},
};


/* If no partition-table was found, we use this default-set.
 * Default flash size is 8MB (NOR). CONFIG_ETRAX_PTABLE_SECTOR is most
 * likely the size of one flash block and "filesystem"-partition needs
 * to be >=5 blocks to be able to use JFFS.
 */
static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
	{
		.name = "boot firmware",
		.size = CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = 0
	},
	{
		.name = "kernel",
		.size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = CONFIG_ETRAX_PTABLE_SECTOR
	},
#define FILESYSTEM_SECTOR (11 * CONFIG_ETRAX_PTABLE_SECTOR)
#ifdef CONFIG_ETRAX_NANDBOOT
	{
		.name = "rootfs",
		.size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = FILESYSTEM_SECTOR
	},
#undef FILESYSTEM_SECTOR
#define FILESYSTEM_SECTOR (21 * CONFIG_ETRAX_PTABLE_SECTOR)
#endif
	{
		.name = "rwfs",
		.size = DEFAULT_MEDIA_SIZE - FILESYSTEM_SECTOR,
		.offset = FILESYSTEM_SECTOR
	}
};

#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
/* Main flash device */
static struct mtd_partition main_partition = {
	.name = "main",
	.size = 0,
	.offset = 0
};
#endif

/* Auxiliary partition if we find another flash */
static struct mtd_partition aux_partition = {
	.name = "aux",
	.size = 0,
	.offset = 0
};

/*
 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
 * chips in that order (because the amd_flash-driver is faster).
 */
static struct mtd_info *probe_cs(struct map_info *map_cs)
{
	struct mtd_info *mtd_cs = NULL;

	printk(KERN_INFO
	       "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
	       map_cs->name, map_cs->size, map_cs->map_priv_1);

#ifdef CONFIG_MTD_CFI
	mtd_cs = do_map_probe("cfi_probe", map_cs);
#endif
#ifdef CONFIG_MTD_JEDECPROBE
	if (!mtd_cs)
		mtd_cs = do_map_probe("jedec_probe", map_cs);
#endif

	return mtd_cs;
}

/*
 * Probe each chip select individually for flash chips. If there are chips on
 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
 * so that MTD partitions can cross chip boundries.
 *
 * The only known restriction to how you can mount your chips is that each
 * chip select must hold similar flash chips. But you need external hardware
 * to do that anyway and you can put totally different chips on cse0 and cse1
 * so it isn't really much of a restriction.
 */
extern struct mtd_info* __init crisv32_nand_flash_probe (void);
static struct mtd_info *flash_probe(void)
{
	struct mtd_info *mtd_cse0;
	struct mtd_info *mtd_cse1;
	struct mtd_info *mtd_total;
	struct mtd_info *mtds[2];
	int count = 0;

	if ((mtd_cse0 = probe_cs(&map_cse0)) != NULL)
		mtds[count++] = mtd_cse0;
	if ((mtd_cse1 = probe_cs(&map_cse1)) != NULL)
		mtds[count++] = mtd_cse1;

	if (!mtd_cse0 && !mtd_cse1) {
		/* No chip found. */
		return NULL;
	}

	if (count > 1) {
		/* Since the concatenation layer adds a small overhead we
		 * could try to figure out if the chips in cse0 and cse1 are
		 * identical and reprobe the whole cse0+cse1 window. But since
		 * flash chips are slow, the overhead is relatively small.
		 * So we use the MTD concatenation layer instead of further
		 * complicating the probing procedure.
		 */
		mtd_total = mtd_concat_create(mtds, count, "cse0+cse1");
		if (!mtd_total) {
			printk(KERN_ERR "%s and %s: Concatenation failed!\n",
				map_cse0.name, map_cse1.name);

			/* The best we can do now is to only use what we found
			 * at cse0. */
			mtd_total = mtd_cse0;
			map_destroy(mtd_cse1);
		}
	} else
		mtd_total = mtd_cse0 ? mtd_cse0 : mtd_cse1;

	return mtd_total;
}

/*
 * Probe the flash chip(s) and, if it succeeds, read the partition-table
 * and register the partitions with MTD.
 */
static int __init init_axis_flash(void)
{
	struct mtd_info *main_mtd;
	struct mtd_info *aux_mtd = NULL;
	int err = 0;
	int pidx = 0;
	struct partitiontable_head *ptable_head = NULL;
	struct partitiontable_entry *ptable;
	int ptable_ok = 0;
	static char page[PAGESIZE];
	size_t len;
	int ram_rootfs_partition = -1; /* -1 => no RAM rootfs partition */
	int part;

	/* We need a root fs. If it resides in RAM, we need to use an
	 * MTDRAM device, so it must be enabled in the kernel config,
	 * but its size must be configured as 0 so as not to conflict
	 * with our usage.
	 */
#if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
	if (!romfs_in_flash && !nand_boot) {
		printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
		       "device; configure CONFIG_MTD_MTDRAM with size = 0!\n");
		panic("This kernel cannot boot from RAM!\n");
	}
#endif

#ifndef CONFIG_ETRAX_VCS_SIM
	main_mtd = flash_probe();
	if (main_mtd)
		printk(KERN_INFO "%s: 0x%08x bytes of NOR flash memory.\n",
		       main_mtd->name, main_mtd->size);

#ifdef CONFIG_ETRAX_NANDFLASH
	aux_mtd = crisv32_nand_flash_probe();
	if (aux_mtd)
		printk(KERN_INFO "%s: 0x%08x bytes of NAND flash memory.\n",
			aux_mtd->name, aux_mtd->size);

#ifdef CONFIG_ETRAX_NANDBOOT
	{
		struct mtd_info *tmp_mtd;

		printk(KERN_INFO "axisflashmap: Set to boot from NAND flash, "
		       "making NAND flash primary device.\n");
		tmp_mtd = main_mtd;
		main_mtd = aux_mtd;
		aux_mtd = tmp_mtd;
	}
#endif /* CONFIG_ETRAX_NANDBOOT */
#endif /* CONFIG_ETRAX_NANDFLASH */

	if (!main_mtd && !aux_mtd) {
		/* There's no reason to use this module if no flash chip can
		 * be identified. Make sure that's understood.
		 */
		printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
	}

#if 0 /* Dump flash memory so we can see what is going on */
	if (main_mtd) {
		int sectoraddr, i;
		for (sectoraddr = 0; sectoraddr < 2*65536+4096;
				sectoraddr += PAGESIZE) {
			main_mtd->read(main_mtd, sectoraddr, PAGESIZE, &len,
				page);
			printk(KERN_INFO
			       "Sector at %d (length %d):\n",
			       sectoraddr, len);
			for (i = 0; i < PAGESIZE; i += 16) {
				printk(KERN_INFO
				       "%02x %02x %02x %02x "
				       "%02x %02x %02x %02x "
				       "%02x %02x %02x %02x "
				       "%02x %02x %02x %02x\n",
				       page[i] & 255, page[i+1] & 255,
				       page[i+2] & 255, page[i+3] & 255,
				       page[i+4] & 255, page[i+5] & 255,
				       page[i+6] & 255, page[i+7] & 255,
				       page[i+8] & 255, page[i+9] & 255,
				       page[i+10] & 255, page[i+11] & 255,
				       page[i+12] & 255, page[i+13] & 255,
				       page[i+14] & 255, page[i+15] & 255);
			}
		}
	}
#endif

	if (main_mtd) {
		main_mtd->owner = THIS_MODULE;
		axisflash_mtd = main_mtd;

		loff_t ptable_sector = CONFIG_ETRAX_PTABLE_SECTOR;

		/* First partition (rescue) is always set to the default. */
		pidx++;
#ifdef CONFIG_ETRAX_NANDBOOT
		/* We know where the partition table should be located,
		 * it will be in first good block after that.
		 */
		int blockstat;
		do {
			blockstat = mtd_block_isbad(main_mtd, ptable_sector);
			if (blockstat < 0)
				ptable_sector = 0; /* read error */
			else if (blockstat)
				ptable_sector += main_mtd->erasesize;
		} while (blockstat && ptable_sector);
#endif
		if (ptable_sector) {
			mtd_read(main_mtd, ptable_sector, PAGESIZE, &len,
				 page);
			ptable_head = &((struct partitiontable *) page)->head;
		}

#if 0 /* Dump partition table so we can see what is going on */
		printk(KERN_INFO
		       "axisflashmap: flash read %d bytes at 0x%08x, data: "
		       "%02x %02x %02x %02x %02x %02x %02x %02x\n",
		       len, CONFIG_ETRAX_PTABLE_SECTOR,
		       page[0] & 255, page[1] & 255,
		       page[2] & 255, page[3] & 255,
		       page[4] & 255, page[5] & 255,
		       page[6] & 255, page[7] & 255);
		printk(KERN_INFO
		       "axisflashmap: partition table offset %d, data: "
		       "%02x %02x %02x %02x %02x %02x %02x %02x\n",
		       PARTITION_TABLE_OFFSET,
		       page[PARTITION_TABLE_OFFSET+0] & 255,
		       page[PARTITION_TABLE_OFFSET+1] & 255,
		       page[PARTITION_TABLE_OFFSET+2] & 255,
		       page[PARTITION_TABLE_OFFSET+3] & 255,
		       page[PARTITION_TABLE_OFFSET+4] & 255,
		       page[PARTITION_TABLE_OFFSET+5] & 255,
		       page[PARTITION_TABLE_OFFSET+6] & 255,
		       page[PARTITION_TABLE_OFFSET+7] & 255);
#endif
	}

	if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
	    && (ptable_head->size <
		(MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
		PARTITIONTABLE_END_MARKER_SIZE))
	    && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
				  ptable_head->size -
				  PARTITIONTABLE_END_MARKER_SIZE)
		== PARTITIONTABLE_END_MARKER)) {
		/* Looks like a start, sane length and end of a
		 * partition table, lets check csum etc.
		 */
		struct partitiontable_entry *max_addr =
			(struct partitiontable_entry *)
			((unsigned long)ptable_head + sizeof(*ptable_head) +
			 ptable_head->size);
		unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
		unsigned char *p;
		unsigned long csum = 0;

		ptable = (struct partitiontable_entry *)
			((unsigned long)ptable_head + sizeof(*ptable_head));

		/* Lets be PARANOID, and check the checksum. */
		p = (unsigned char*) ptable;

		while (p <= (unsigned char*)max_addr) {
			csum += *p++;
			csum += *p++;
			csum += *p++;
			csum += *p++;
		}
		ptable_ok = (csum == ptable_head->checksum);

		/* Read the entries and use/show the info.  */
		printk(KERN_INFO "axisflashmap: "
		       "Found a%s partition table at 0x%p-0x%p.\n",
		       (ptable_ok ? " valid" : "n invalid"), ptable_head,
		       max_addr);

		/* We have found a working bootblock.  Now read the
		 * partition table.  Scan the table.  It ends with 0xffffffff.
		 */
		while (ptable_ok
		       && ptable->offset != PARTITIONTABLE_END_MARKER
		       && ptable < max_addr
		       && pidx < MAX_PARTITIONS - 1) {

			axis_partitions[pidx].offset = offset + ptable->offset;
#ifdef CONFIG_ETRAX_NANDFLASH
			if (main_mtd->type == MTD_NANDFLASH) {
				axis_partitions[pidx].size =
					(((ptable+1)->offset ==
					  PARTITIONTABLE_END_MARKER) ?
					  main_mtd->size :
					  ((ptable+1)->offset + offset)) -
					(ptable->offset + offset);

			} else
#endif /* CONFIG_ETRAX_NANDFLASH */
				axis_partitions[pidx].size = ptable->size;
#ifdef CONFIG_ETRAX_NANDBOOT
			/* Save partition number of jffs2 ro partition.
			 * Needed if RAM booting or root file system in RAM.
			 */
			if (!nand_boot &&
			    ram_rootfs_partition < 0 && /* not already set */
			    ptable->type == PARTITION_TYPE_JFFS2 &&
			    (ptable->flags & PARTITION_FLAGS_READONLY_MASK) ==
				PARTITION_FLAGS_READONLY)
				ram_rootfs_partition = pidx;
#endif /* CONFIG_ETRAX_NANDBOOT */
			pidx++;
			ptable++;
		}
	}

	/* Decide whether to use default partition table. */
	/* Only use default table if we actually have a device (main_mtd) */

	struct mtd_partition *partition = &axis_partitions[0];
	if (main_mtd && !ptable_ok) {
		memcpy(axis_partitions, axis_default_partitions,
		       sizeof(axis_default_partitions));
		pidx = NUM_DEFAULT_PARTITIONS;
		ram_rootfs_partition = DEFAULT_ROOTFS_PARTITION_NO;
	}

	/* Add artificial partitions for rootfs if necessary */
	if (romfs_in_flash) {
		/* rootfs is in directly accessible flash memory = NOR flash.
		   Add an overlapping device for the rootfs partition. */
		printk(KERN_INFO "axisflashmap: Adding partition for "
		       "overlapping root file system image\n");
		axis_partitions[pidx].size = romfs_length;
		axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
		axis_partitions[pidx].name = "romfs";
		axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
		ram_rootfs_partition = -1;
		pidx++;
	} else if (romfs_length && !nand_boot) {
		/* romfs exists in memory, but not in flash, so must be in RAM.
		 * Configure an MTDRAM partition. */
		if (ram_rootfs_partition < 0) {
			/* None set yet, put it at the end */
			ram_rootfs_partition = pidx;
			pidx++;
		}
		printk(KERN_INFO "axisflashmap: Adding partition for "
		       "root file system image in RAM\n");
		axis_partitions[ram_rootfs_partition].size = romfs_length;
		axis_partitions[ram_rootfs_partition].offset = romfs_start;
		axis_partitions[ram_rootfs_partition].name = "romfs";
		axis_partitions[ram_rootfs_partition].mask_flags |=
			MTD_WRITEABLE;
	}

#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
	if (main_mtd) {
		main_partition.size = main_mtd->size;
		err = mtd_device_register(main_mtd, &main_partition, 1);
		if (err)
			panic("axisflashmap: Could not initialize "
			      "partition for whole main mtd device!\n");
	}
#endif

	/* Now, register all partitions with mtd.
	 * We do this one at a time so we can slip in an MTDRAM device
	 * in the proper place if required. */

	for (part = 0; part < pidx; part++) {
		if (part == ram_rootfs_partition) {
			/* add MTDRAM partition here */
			struct mtd_info *mtd_ram;

			mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
			if (!mtd_ram)
				panic("axisflashmap: Couldn't allocate memory "
				      "for mtd_info!\n");
			printk(KERN_INFO "axisflashmap: Adding RAM partition "
			       "for rootfs image.\n");
			err = mtdram_init_device(mtd_ram,
						 (void *)partition[part].offset,
						 partition[part].size,
						 partition[part].name);
			if (err)
				panic("axisflashmap: Could not initialize "
				      "MTD RAM device!\n");
			/* JFFS2 likes to have an erasesize. Keep potential
			 * JFFS2 rootfs happy by providing one. Since image
			 * was most likely created for main mtd, use that
			 * erasesize, if available. Otherwise, make a guess. */
			mtd_ram->erasesize = (main_mtd ? main_mtd->erasesize :
				CONFIG_ETRAX_PTABLE_SECTOR);
		} else {
			err = mtd_device_register(main_mtd, &partition[part],
						  1);
			if (err)
				panic("axisflashmap: Could not add mtd "
					"partition %d\n", part);
		}
	}
#endif /* CONFIG_EXTRAX_VCS_SIM */

#ifdef CONFIG_ETRAX_VCS_SIM
	/* For simulator, always use a RAM partition.
	 * The rootfs will be found after the kernel in RAM,
	 * with romfs_start and romfs_end indicating location and size.
	 */
	struct mtd_info *mtd_ram;

	mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
	if (!mtd_ram) {
		panic("axisflashmap: Couldn't allocate memory for "
		      "mtd_info!\n");
	}

	printk(KERN_INFO "axisflashmap: Adding RAM partition for romfs, "
	       "at %u, size %u\n",
	       (unsigned) romfs_start, (unsigned) romfs_length);

	err = mtdram_init_device(mtd_ram, (void *)romfs_start,
				 romfs_length, "romfs");
	if (err) {
		panic("axisflashmap: Could not initialize MTD RAM "
		      "device!\n");
	}
#endif /* CONFIG_EXTRAX_VCS_SIM */

#ifndef CONFIG_ETRAX_VCS_SIM
	if (aux_mtd) {
		aux_partition.size = aux_mtd->size;
		err = mtd_device_register(aux_mtd, &aux_partition, 1);
		if (err)
			panic("axisflashmap: Could not initialize "
			      "aux mtd device!\n");

	}
#endif /* CONFIG_EXTRAX_VCS_SIM */

	return err;
}

/* This adds the above to the kernels init-call chain. */
module_init(init_axis_flash);

EXPORT_SYMBOL(axisflash_mtd);