2 * Physical mapping layer for MTD using the Axis partitiontable format
4 * Copyright (c) 2001-2007 Axis Communications AB
6 * This file is under the GPL.
8 * First partition is always sector 0 regardless of if we find a partitiontable
9 * or not. In the start of the next sector, there can be a partitiontable that
10 * tells us what other partitions to define. If there isn't, we use a default
11 * partition split defined below.
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
21 #include <linux/mtd/concat.h>
22 #include <linux/mtd/map.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/mtdram.h>
25 #include <linux/mtd/partitions.h>
27 #include <asm/axisflashmap.h>
30 #define MEM_CSE0_SIZE (0x04000000)
31 #define MEM_CSE1_SIZE (0x04000000)
33 #define FLASH_UNCACHED_ADDR KSEG_E
34 #define FLASH_CACHED_ADDR KSEG_F
36 #define PAGESIZE (512)
38 #if CONFIG_ETRAX_FLASH_BUSWIDTH==1
39 #define flash_data __u8
40 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
41 #define flash_data __u16
42 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
43 #define flash_data __u32
47 extern unsigned long romfs_in_flash; /* 1 when romfs_start, _length in flash */
48 extern unsigned long romfs_start, romfs_length;
49 extern unsigned long nand_boot; /* 1 when booted from nand flash */
51 struct partition_name {
55 /* The master mtd for the entire flash. */
56 struct mtd_info* axisflash_mtd = NULL;
58 /* Map driver functions. */
60 static map_word flash_read(struct map_info *map, unsigned long ofs)
63 tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
67 static void flash_copy_from(struct map_info *map, void *to,
68 unsigned long from, ssize_t len)
70 memcpy(to, (void *)(map->map_priv_1 + from), len);
73 static void flash_write(struct map_info *map, map_word d, unsigned long adr)
75 *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
79 * The map for chip select e0.
81 * We run into tricky coherence situations if we mix cached with uncached
82 * accesses to we only use the uncached version here.
84 * The size field is the total size where the flash chips may be mapped on the
85 * chip select. MTD probes should find all devices there and it does not matter
86 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
87 * probes will ignore them.
89 * The start address in map_priv_1 is in virtual memory so we cannot use
90 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
93 static struct map_info map_cse0 = {
95 .size = MEM_CSE0_SIZE,
96 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
98 .copy_from = flash_copy_from,
100 .map_priv_1 = FLASH_UNCACHED_ADDR
104 * The map for chip select e1.
106 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
107 * address, but there isn't.
109 static struct map_info map_cse1 = {
111 .size = MEM_CSE1_SIZE,
112 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
114 .copy_from = flash_copy_from,
115 .write = flash_write,
116 .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
119 #define MAX_PARTITIONS 7
120 #ifdef CONFIG_ETRAX_NANDBOOT
121 #define NUM_DEFAULT_PARTITIONS 4
122 #define DEFAULT_ROOTFS_PARTITION_NO 2
123 #define DEFAULT_MEDIA_SIZE 0x2000000 /* 32 megs */
125 #define NUM_DEFAULT_PARTITIONS 3
126 #define DEFAULT_ROOTFS_PARTITION_NO (-1)
127 #define DEFAULT_MEDIA_SIZE 0x800000 /* 8 megs */
130 #if (MAX_PARTITIONS < NUM_DEFAULT_PARTITIONS)
131 #error MAX_PARTITIONS must be >= than NUM_DEFAULT_PARTITIONS
134 /* Initialize the ones normally used. */
135 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
138 .size = CONFIG_ETRAX_PTABLE_SECTOR,
174 /* If no partition-table was found, we use this default-set.
175 * Default flash size is 8MB (NOR). CONFIG_ETRAX_PTABLE_SECTOR is most
176 * likely the size of one flash block and "filesystem"-partition needs
177 * to be >=5 blocks to be able to use JFFS.
179 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
181 .name = "boot firmware",
182 .size = CONFIG_ETRAX_PTABLE_SECTOR,
187 .size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
188 .offset = CONFIG_ETRAX_PTABLE_SECTOR
190 #define FILESYSTEM_SECTOR (11 * CONFIG_ETRAX_PTABLE_SECTOR)
191 #ifdef CONFIG_ETRAX_NANDBOOT
194 .size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
195 .offset = FILESYSTEM_SECTOR
197 #undef FILESYSTEM_SECTOR
198 #define FILESYSTEM_SECTOR (21 * CONFIG_ETRAX_PTABLE_SECTOR)
202 .size = DEFAULT_MEDIA_SIZE - FILESYSTEM_SECTOR,
203 .offset = FILESYSTEM_SECTOR
207 #ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
208 /* Main flash device */
209 static struct mtd_partition main_partition = {
216 /* Auxiliary partition if we find another flash */
217 static struct mtd_partition aux_partition = {
224 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
225 * chips in that order (because the amd_flash-driver is faster).
227 static struct mtd_info *probe_cs(struct map_info *map_cs)
229 struct mtd_info *mtd_cs = NULL;
232 "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
233 map_cs->name, map_cs->size, map_cs->map_priv_1);
235 #ifdef CONFIG_MTD_CFI
236 mtd_cs = do_map_probe("cfi_probe", map_cs);
238 #ifdef CONFIG_MTD_JEDECPROBE
240 mtd_cs = do_map_probe("jedec_probe", map_cs);
247 * Probe each chip select individually for flash chips. If there are chips on
248 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
249 * so that MTD partitions can cross chip boundaries.
251 * The only known restriction to how you can mount your chips is that each
252 * chip select must hold similar flash chips. But you need external hardware
253 * to do that anyway and you can put totally different chips on cse0 and cse1
254 * so it isn't really much of a restriction.
256 extern struct mtd_info* __init crisv32_nand_flash_probe (void);
257 static struct mtd_info *flash_probe(void)
259 struct mtd_info *mtd_cse0;
260 struct mtd_info *mtd_cse1;
261 struct mtd_info *mtd_total;
262 struct mtd_info *mtds[2];
265 if ((mtd_cse0 = probe_cs(&map_cse0)) != NULL)
266 mtds[count++] = mtd_cse0;
267 if ((mtd_cse1 = probe_cs(&map_cse1)) != NULL)
268 mtds[count++] = mtd_cse1;
270 if (!mtd_cse0 && !mtd_cse1) {
276 /* Since the concatenation layer adds a small overhead we
277 * could try to figure out if the chips in cse0 and cse1 are
278 * identical and reprobe the whole cse0+cse1 window. But since
279 * flash chips are slow, the overhead is relatively small.
280 * So we use the MTD concatenation layer instead of further
281 * complicating the probing procedure.
283 mtd_total = mtd_concat_create(mtds, count, "cse0+cse1");
285 printk(KERN_ERR "%s and %s: Concatenation failed!\n",
286 map_cse0.name, map_cse1.name);
288 /* The best we can do now is to only use what we found
290 mtd_total = mtd_cse0;
291 map_destroy(mtd_cse1);
294 mtd_total = mtd_cse0 ? mtd_cse0 : mtd_cse1;
300 * Probe the flash chip(s) and, if it succeeds, read the partition-table
301 * and register the partitions with MTD.
303 static int __init init_axis_flash(void)
305 struct mtd_info *main_mtd;
306 struct mtd_info *aux_mtd = NULL;
309 struct partitiontable_head *ptable_head = NULL;
310 struct partitiontable_entry *ptable;
312 static char page[PAGESIZE];
314 int ram_rootfs_partition = -1; /* -1 => no RAM rootfs partition */
316 struct mtd_partition *partition;
318 /* We need a root fs. If it resides in RAM, we need to use an
319 * MTDRAM device, so it must be enabled in the kernel config,
320 * but its size must be configured as 0 so as not to conflict
323 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0)
324 if (!romfs_in_flash && !nand_boot) {
325 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
326 "device; configure CONFIG_MTD_MTDRAM with size = 0!\n");
327 panic("This kernel cannot boot from RAM!\n");
331 main_mtd = flash_probe();
333 printk(KERN_INFO "%s: 0x%08llx bytes of NOR flash memory.\n",
334 main_mtd->name, main_mtd->size);
336 #ifdef CONFIG_ETRAX_NANDFLASH
337 aux_mtd = crisv32_nand_flash_probe();
339 printk(KERN_INFO "%s: 0x%08x bytes of NAND flash memory.\n",
340 aux_mtd->name, aux_mtd->size);
342 #ifdef CONFIG_ETRAX_NANDBOOT
344 struct mtd_info *tmp_mtd;
346 printk(KERN_INFO "axisflashmap: Set to boot from NAND flash, "
347 "making NAND flash primary device.\n");
352 #endif /* CONFIG_ETRAX_NANDBOOT */
353 #endif /* CONFIG_ETRAX_NANDFLASH */
355 if (!main_mtd && !aux_mtd) {
356 /* There's no reason to use this module if no flash chip can
357 * be identified. Make sure that's understood.
359 printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
362 #if 0 /* Dump flash memory so we can see what is going on */
365 for (sectoraddr = 0; sectoraddr < 2*65536+4096;
366 sectoraddr += PAGESIZE) {
367 main_mtd->read(main_mtd, sectoraddr, PAGESIZE, &len,
370 "Sector at %d (length %d):\n",
372 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, page, PAGESIZE, false);
378 loff_t ptable_sector = CONFIG_ETRAX_PTABLE_SECTOR;
379 main_mtd->owner = THIS_MODULE;
380 axisflash_mtd = main_mtd;
383 /* First partition (rescue) is always set to the default. */
385 #ifdef CONFIG_ETRAX_NANDBOOT
386 /* We know where the partition table should be located,
387 * it will be in first good block after that.
391 blockstat = mtd_block_isbad(main_mtd, ptable_sector);
393 ptable_sector = 0; /* read error */
395 ptable_sector += main_mtd->erasesize;
396 } while (blockstat && ptable_sector);
399 mtd_read(main_mtd, ptable_sector, PAGESIZE, &len,
401 ptable_head = &((struct partitiontable *) page)->head;
404 #if 0 /* Dump partition table so we can see what is going on */
406 "axisflashmap: flash read %d bytes at 0x%08x, data: %8ph\n",
407 len, CONFIG_ETRAX_PTABLE_SECTOR, page);
409 "axisflashmap: partition table offset %d, data: %8ph\n",
410 PARTITION_TABLE_OFFSET, page + PARTITION_TABLE_OFFSET);
414 if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
415 && (ptable_head->size <
416 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
417 PARTITIONTABLE_END_MARKER_SIZE))
418 && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
420 PARTITIONTABLE_END_MARKER_SIZE)
421 == PARTITIONTABLE_END_MARKER)) {
422 /* Looks like a start, sane length and end of a
423 * partition table, lets check csum etc.
425 struct partitiontable_entry *max_addr =
426 (struct partitiontable_entry *)
427 ((unsigned long)ptable_head + sizeof(*ptable_head) +
429 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
431 unsigned long csum = 0;
433 ptable = (struct partitiontable_entry *)
434 ((unsigned long)ptable_head + sizeof(*ptable_head));
436 /* Lets be PARANOID, and check the checksum. */
437 p = (unsigned char*) ptable;
439 while (p <= (unsigned char*)max_addr) {
445 ptable_ok = (csum == ptable_head->checksum);
447 /* Read the entries and use/show the info. */
448 printk(KERN_INFO "axisflashmap: "
449 "Found a%s partition table at 0x%p-0x%p.\n",
450 (ptable_ok ? " valid" : "n invalid"), ptable_head,
453 /* We have found a working bootblock. Now read the
454 * partition table. Scan the table. It ends with 0xffffffff.
457 && ptable->offset != PARTITIONTABLE_END_MARKER
459 && pidx < MAX_PARTITIONS - 1) {
461 axis_partitions[pidx].offset = offset + ptable->offset;
462 #ifdef CONFIG_ETRAX_NANDFLASH
463 if (main_mtd->type == MTD_NANDFLASH) {
464 axis_partitions[pidx].size =
465 (((ptable+1)->offset ==
466 PARTITIONTABLE_END_MARKER) ?
468 ((ptable+1)->offset + offset)) -
469 (ptable->offset + offset);
472 #endif /* CONFIG_ETRAX_NANDFLASH */
473 axis_partitions[pidx].size = ptable->size;
474 #ifdef CONFIG_ETRAX_NANDBOOT
475 /* Save partition number of jffs2 ro partition.
476 * Needed if RAM booting or root file system in RAM.
479 ram_rootfs_partition < 0 && /* not already set */
480 ptable->type == PARTITION_TYPE_JFFS2 &&
481 (ptable->flags & PARTITION_FLAGS_READONLY_MASK) ==
482 PARTITION_FLAGS_READONLY)
483 ram_rootfs_partition = pidx;
484 #endif /* CONFIG_ETRAX_NANDBOOT */
490 /* Decide whether to use default partition table. */
491 /* Only use default table if we actually have a device (main_mtd) */
493 partition = &axis_partitions[0];
494 if (main_mtd && !ptable_ok) {
495 memcpy(axis_partitions, axis_default_partitions,
496 sizeof(axis_default_partitions));
497 pidx = NUM_DEFAULT_PARTITIONS;
498 ram_rootfs_partition = DEFAULT_ROOTFS_PARTITION_NO;
501 /* Add artificial partitions for rootfs if necessary */
502 if (romfs_in_flash) {
503 /* rootfs is in directly accessible flash memory = NOR flash.
504 Add an overlapping device for the rootfs partition. */
505 printk(KERN_INFO "axisflashmap: Adding partition for "
506 "overlapping root file system image\n");
507 axis_partitions[pidx].size = romfs_length;
508 axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
509 axis_partitions[pidx].name = "romfs";
510 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
511 ram_rootfs_partition = -1;
513 } else if (romfs_length && !nand_boot) {
514 /* romfs exists in memory, but not in flash, so must be in RAM.
515 * Configure an MTDRAM partition. */
516 if (ram_rootfs_partition < 0) {
517 /* None set yet, put it at the end */
518 ram_rootfs_partition = pidx;
521 printk(KERN_INFO "axisflashmap: Adding partition for "
522 "root file system image in RAM\n");
523 axis_partitions[ram_rootfs_partition].size = romfs_length;
524 axis_partitions[ram_rootfs_partition].offset = romfs_start;
525 axis_partitions[ram_rootfs_partition].name = "romfs";
526 axis_partitions[ram_rootfs_partition].mask_flags |=
530 #ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
532 main_partition.size = main_mtd->size;
533 err = mtd_device_register(main_mtd, &main_partition, 1);
535 panic("axisflashmap: Could not initialize "
536 "partition for whole main mtd device!\n");
540 /* Now, register all partitions with mtd.
541 * We do this one at a time so we can slip in an MTDRAM device
542 * in the proper place if required. */
544 for (part = 0; part < pidx; part++) {
545 if (part == ram_rootfs_partition) {
546 /* add MTDRAM partition here */
547 struct mtd_info *mtd_ram;
549 mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
551 panic("axisflashmap: Couldn't allocate memory "
553 printk(KERN_INFO "axisflashmap: Adding RAM partition "
554 "for rootfs image.\n");
555 err = mtdram_init_device(mtd_ram,
556 (void *)(u_int32_t)partition[part].offset,
557 partition[part].size,
558 partition[part].name);
560 panic("axisflashmap: Could not initialize "
561 "MTD RAM device!\n");
562 /* JFFS2 likes to have an erasesize. Keep potential
563 * JFFS2 rootfs happy by providing one. Since image
564 * was most likely created for main mtd, use that
565 * erasesize, if available. Otherwise, make a guess. */
566 mtd_ram->erasesize = (main_mtd ? main_mtd->erasesize :
567 CONFIG_ETRAX_PTABLE_SECTOR);
569 err = mtd_device_register(main_mtd, &partition[part],
572 panic("axisflashmap: Could not add mtd "
573 "partition %d\n", part);
578 aux_partition.size = aux_mtd->size;
579 err = mtd_device_register(aux_mtd, &aux_partition, 1);
581 panic("axisflashmap: Could not initialize "
582 "aux mtd device!\n");
589 /* This adds the above to the kernels init-call chain. */
590 module_init(init_axis_flash);
592 EXPORT_SYMBOL(axisflash_mtd);