2 * Physical mapping layer for MTD using the Axis partitiontable format
4 * Copyright (c) 2001, 2002 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.
13 * $Log: axisflashmap.c,v $
14 * Revision 1.11 2004/11/15 10:27:14 starvik
15 * Corrected typo (Thanks to Milton Miller <miltonm@bga.com>).
17 * Revision 1.10 2004/08/16 12:37:22 starvik
18 * Merge of Linux 2.6.8
20 * Revision 1.8 2004/05/14 07:58:03 starvik
21 * Merge of changes from 2.4
23 * Revision 1.6 2003/07/04 08:27:37 starvik
24 * Merge of Linux 2.5.74
26 * Revision 1.5 2002/12/11 13:13:57 starvik
27 * Added arch/ to v10 specific includes
28 * Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
30 * Revision 1.4 2002/11/20 11:56:10 starvik
31 * Merge of Linux 2.5.48
33 * Revision 1.3 2002/11/13 14:54:13 starvik
34 * Copied from linux 2.4
36 * Revision 1.28 2002/10/01 08:08:43 jonashg
37 * The first partition ends at the start of the partition table.
39 * Revision 1.27 2002/08/21 09:23:13 jonashg
42 * Revision 1.26 2002/08/21 08:35:20 jonashg
43 * Cosmetic change to printouts.
45 * Revision 1.25 2002/08/21 08:15:42 jonashg
46 * Made it compile even without CONFIG_MTD_CONCAT defined.
48 * Revision 1.24 2002/08/20 13:12:35 jonashg
49 * * New approach to probing. Probe cse0 and cse1 separately and (mtd)concat
51 * * Removed compile time tests concerning how the mtdram driver has been
52 * configured. The user will know about the misconfiguration at runtime
53 * instead. (The old approach made it impossible to use mtdram for anything
54 * else than RAM boot).
56 * Revision 1.23 2002/05/13 12:12:28 johana
57 * Allow compile without CONFIG_MTD_MTDRAM but warn at compiletime and
58 * be informative at runtime.
60 * Revision 1.22 2002/05/13 10:24:44 johana
61 * Added #if checks on MTDRAM CONFIG
63 * Revision 1.21 2002/05/06 16:05:20 johana
64 * Removed debug printout.
66 * Revision 1.20 2002/05/06 16:03:00 johana
67 * No more cramfs as root hack in generic code.
68 * It's handled by axisflashmap using mtdram.
70 * Revision 1.19 2002/03/15 17:10:28 bjornw
71 * Changed comment about cached access since we changed this before
73 * Revision 1.18 2002/03/05 17:06:15 jonashg
74 * Try amd_flash probe before cfi_probe since amd_flash driver can handle two
75 * (or more) flash chips of different model and the cfi driver cannot.
77 * Revision 1.17 2001/11/12 19:42:38 pkj
78 * Fixed compiler warnings.
80 * Revision 1.16 2001/11/08 11:18:58 jonashg
81 * Always read from uncached address to avoid problems with flushing
82 * cachelines after write and MTD-erase. No performance loss have been
85 * Revision 1.15 2001/10/19 12:41:04 jonashg
86 * Name of probe has changed in MTD.
88 * Revision 1.14 2001/09/21 07:14:10 jonashg
89 * Made root filesystem (cramfs) use mtdblock driver when booting from flash.
91 * Revision 1.13 2001/08/15 13:57:35 jonashg
92 * Entire MTD updated to the linux 2.4.7 version.
94 * Revision 1.12 2001/06/11 09:50:30 jonashg
95 * Oops, 2MB is 0x200000 bytes.
97 * Revision 1.11 2001/06/08 11:39:44 jonashg
98 * Changed sizes and offsets in axis_default_partitions to use
99 * CONFIG_ETRAX_PTABLE_SECTOR.
101 * Revision 1.10 2001/05/29 09:42:03 jonashg
102 * Use macro for end marker length instead of sizeof.
104 * Revision 1.9 2001/05/29 08:52:52 jonashg
105 * Gave names to the magic fours (size of the ptable end marker).
107 * Revision 1.8 2001/05/28 15:36:20 jonashg
108 * * Removed old comment about ptable location in flash (it's a CONFIG_ option).
109 * * Variable ptable was initialized twice to the same value.
111 * Revision 1.7 2001/04/05 13:41:46 markusl
112 * Updated according to review remarks
114 * Revision 1.6 2001/03/07 09:21:21 bjornw
115 * No need to waste .data
117 * Revision 1.5 2001/03/06 16:27:01 jonashg
118 * Probe the entire flash area for flash devices.
120 * Revision 1.4 2001/02/23 12:47:15 bjornw
121 * Uncached flash in LOW_MAP moved from 0xe to 0x8
123 * Revision 1.3 2001/02/16 12:11:45 jonashg
124 * MTD driver amd_flash is now included in MTD CVS repository.
125 * (It's now in drivers/mtd).
127 * Revision 1.2 2001/02/09 11:12:22 jonashg
128 * Support for AMD compatible non-CFI flash chips.
129 * Only tested with Toshiba TC58FVT160 so far.
131 * Revision 1.1 2001/01/12 17:01:18 bjornw
132 * * Added axisflashmap.c, a physical mapping for MTD that reads and understands
133 * Axis partition-table format.
138 #include <linux/module.h>
139 #include <linux/types.h>
140 #include <linux/kernel.h>
141 #include <linux/config.h>
142 #include <linux/init.h>
143 #include <linux/slab.h>
145 #include <linux/mtd/concat.h>
146 #include <linux/mtd/map.h>
147 #include <linux/mtd/mtd.h>
148 #include <linux/mtd/mtdram.h>
149 #include <linux/mtd/partitions.h>
151 #include <asm/axisflashmap.h>
153 #include <asm/arch/sv_addr_ag.h>
155 #ifdef CONFIG_CRIS_LOW_MAP
156 #define FLASH_UNCACHED_ADDR KSEG_8
157 #define FLASH_CACHED_ADDR KSEG_5
159 #define FLASH_UNCACHED_ADDR KSEG_E
160 #define FLASH_CACHED_ADDR KSEG_F
163 #if CONFIG_ETRAX_FLASH_BUSWIDTH==1
164 #define flash_data __u8
165 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
166 #define flash_data __u16
167 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
168 #define flash_data __u32
172 extern unsigned long romfs_start, romfs_length, romfs_in_flash;
174 /* The master mtd for the entire flash. */
175 struct mtd_info* axisflash_mtd = NULL;
177 /* Map driver functions. */
179 static map_word flash_read(struct map_info *map, unsigned long ofs)
182 tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
186 static void flash_copy_from(struct map_info *map, void *to,
187 unsigned long from, ssize_t len)
189 memcpy(to, (void *)(map->map_priv_1 + from), len);
192 static void flash_write(struct map_info *map, map_word d, unsigned long adr)
194 *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
198 * The map for chip select e0.
200 * We run into tricky coherence situations if we mix cached with uncached
201 * accesses to we only use the uncached version here.
203 * The size field is the total size where the flash chips may be mapped on the
204 * chip select. MTD probes should find all devices there and it does not matter
205 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
206 * probes will ignore them.
208 * The start address in map_priv_1 is in virtual memory so we cannot use
209 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
212 static struct map_info map_cse0 = {
214 .size = MEM_CSE0_SIZE,
215 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
217 .copy_from = flash_copy_from,
218 .write = flash_write,
219 .map_priv_1 = FLASH_UNCACHED_ADDR
223 * The map for chip select e1.
225 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
226 * address, but there isn't.
228 static struct map_info map_cse1 = {
230 .size = MEM_CSE1_SIZE,
231 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
233 .copy_from = flash_copy_from,
234 .write = flash_write,
235 .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
238 /* If no partition-table was found, we use this default-set. */
239 #define MAX_PARTITIONS 7
240 #define NUM_DEFAULT_PARTITIONS 3
243 * Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
244 * size of one flash block and "filesystem"-partition needs 5 blocks to be able
247 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
249 .name = "boot firmware",
250 .size = CONFIG_ETRAX_PTABLE_SECTOR,
255 .size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
256 .offset = CONFIG_ETRAX_PTABLE_SECTOR
259 .name = "filesystem",
260 .size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
261 .offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
265 /* Initialize the ones normally used. */
266 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
269 .size = CONFIG_ETRAX_PTABLE_SECTOR,
305 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
306 * chips in that order (because the amd_flash-driver is faster).
308 static struct mtd_info *probe_cs(struct map_info *map_cs)
310 struct mtd_info *mtd_cs = NULL;
313 "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
314 map_cs->name, map_cs->size, map_cs->map_priv_1);
316 #ifdef CONFIG_MTD_AMDSTD
317 mtd_cs = do_map_probe("amd_flash", map_cs);
319 #ifdef CONFIG_MTD_CFI
321 mtd_cs = do_map_probe("cfi_probe", map_cs);
329 * Probe each chip select individually for flash chips. If there are chips on
330 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
331 * so that MTD partitions can cross chip boundries.
333 * The only known restriction to how you can mount your chips is that each
334 * chip select must hold similar flash chips. But you need external hardware
335 * to do that anyway and you can put totally different chips on cse0 and cse1
336 * so it isn't really much of a restriction.
338 static struct mtd_info *flash_probe(void)
340 struct mtd_info *mtd_cse0;
341 struct mtd_info *mtd_cse1;
342 struct mtd_info *mtd_cse;
344 mtd_cse0 = probe_cs(&map_cse0);
345 mtd_cse1 = probe_cs(&map_cse1);
347 if (!mtd_cse0 && !mtd_cse1) {
352 if (mtd_cse0 && mtd_cse1) {
353 #ifdef CONFIG_MTD_CONCAT
354 struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };
356 /* Since the concatenation layer adds a small overhead we
357 * could try to figure out if the chips in cse0 and cse1 are
358 * identical and reprobe the whole cse0+cse1 window. But since
359 * flash chips are slow, the overhead is relatively small.
360 * So we use the MTD concatenation layer instead of further
361 * complicating the probing procedure.
363 mtd_cse = mtd_concat_create(mtds,
364 sizeof(mtds) / sizeof(mtds[0]),
367 printk(KERN_ERR "%s and %s: Cannot concatenate due to kernel "
368 "(mis)configuration!\n", map_cse0.name, map_cse1.name);
372 printk(KERN_ERR "%s and %s: Concatenation failed!\n",
373 map_cse0.name, map_cse1.name);
375 /* The best we can do now is to only use what we found
379 map_destroy(mtd_cse1);
382 mtd_cse = mtd_cse0? mtd_cse0 : mtd_cse1;
389 * Probe the flash chip(s) and, if it succeeds, read the partition-table
390 * and register the partitions with MTD.
392 static int __init init_axis_flash(void)
394 struct mtd_info *mymtd;
397 struct partitiontable_head *ptable_head = NULL;
398 struct partitiontable_entry *ptable;
399 int use_default_ptable = 1; /* Until proven otherwise. */
400 const char *pmsg = " /dev/flash%d at 0x%08x, size 0x%08x\n";
402 if (!(mymtd = flash_probe())) {
403 /* There's no reason to use this module if no flash chip can
404 * be identified. Make sure that's understood.
406 printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
408 printk(KERN_INFO "%s: 0x%08x bytes of flash memory.\n",
409 mymtd->name, mymtd->size);
410 axisflash_mtd = mymtd;
414 mymtd->owner = THIS_MODULE;
415 ptable_head = (struct partitiontable_head *)(FLASH_CACHED_ADDR +
416 CONFIG_ETRAX_PTABLE_SECTOR +
417 PARTITION_TABLE_OFFSET);
419 pidx++; /* First partition is always set to the default. */
421 if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
422 && (ptable_head->size <
423 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
424 PARTITIONTABLE_END_MARKER_SIZE))
425 && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
427 PARTITIONTABLE_END_MARKER_SIZE)
428 == PARTITIONTABLE_END_MARKER)) {
429 /* Looks like a start, sane length and end of a
430 * partition table, lets check csum etc.
433 struct partitiontable_entry *max_addr =
434 (struct partitiontable_entry *)
435 ((unsigned long)ptable_head + sizeof(*ptable_head) +
437 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
439 unsigned long csum = 0;
441 ptable = (struct partitiontable_entry *)
442 ((unsigned long)ptable_head + sizeof(*ptable_head));
444 /* Lets be PARANOID, and check the checksum. */
445 p = (unsigned char*) ptable;
447 while (p <= (unsigned char*)max_addr) {
453 ptable_ok = (csum == ptable_head->checksum);
455 /* Read the entries and use/show the info. */
456 printk(KERN_INFO " Found a%s partition table at 0x%p-0x%p.\n",
457 (ptable_ok ? " valid" : "n invalid"), ptable_head,
460 /* We have found a working bootblock. Now read the
461 * partition table. Scan the table. It ends when
462 * there is 0xffffffff, that is, empty flash.
465 && ptable->offset != 0xffffffff
467 && pidx < MAX_PARTITIONS) {
469 axis_partitions[pidx].offset = offset + ptable->offset;
470 axis_partitions[pidx].size = ptable->size;
472 printk(pmsg, pidx, axis_partitions[pidx].offset,
473 axis_partitions[pidx].size);
477 use_default_ptable = !ptable_ok;
480 if (romfs_in_flash) {
481 /* Add an overlapping device for the root partition (romfs). */
483 axis_partitions[pidx].name = "romfs";
484 axis_partitions[pidx].size = romfs_length;
485 axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
486 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
489 " Adding readonly flash partition for romfs image:\n");
490 printk(pmsg, pidx, axis_partitions[pidx].offset,
491 axis_partitions[pidx].size);
496 if (use_default_ptable) {
497 printk(KERN_INFO " Using default partition table.\n");
498 err = add_mtd_partitions(mymtd, axis_default_partitions,
499 NUM_DEFAULT_PARTITIONS);
501 err = add_mtd_partitions(mymtd, axis_partitions, pidx);
505 panic("axisflashmap could not add MTD partitions!\n");
509 if (!romfs_in_flash) {
510 /* Create an RAM device for the root partition (romfs). */
512 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
513 /* No use trying to boot this kernel from RAM. Panic! */
514 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
515 "device due to kernel (mis)configuration!\n");
516 panic("This kernel cannot boot from RAM!\n");
518 struct mtd_info *mtd_ram;
520 mtd_ram = (struct mtd_info *)kmalloc(sizeof(struct mtd_info),
523 panic("axisflashmap couldn't allocate memory for "
527 printk(KERN_INFO " Adding RAM partition for romfs image:\n");
528 printk(pmsg, pidx, romfs_start, romfs_length);
530 err = mtdram_init_device(mtd_ram, (void*)romfs_start,
531 romfs_length, "romfs");
533 panic("axisflashmap could not initialize MTD RAM "
542 /* This adds the above to the kernels init-call chain. */
543 module_init(init_axis_flash);
545 EXPORT_SYMBOL(axisflash_mtd);