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 1.6 2003/07/04 08:27:37 starvik
15 * Merge of Linux 2.5.74
17 * Revision 1.5 2002/12/11 13:13:57 starvik
18 * Added arch/ to v10 specific includes
19 * Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
21 * Revision 1.4 2002/11/20 11:56:10 starvik
22 * Merge of Linux 2.5.48
24 * Revision 1.3 2002/11/13 14:54:13 starvik
25 * Copied from linux 2.4
27 * Revision 1.28 2002/10/01 08:08:43 jonashg
28 * The first partition ends at the start of the partition table.
30 * Revision 1.27 2002/08/21 09:23:13 jonashg
33 * Revision 1.26 2002/08/21 08:35:20 jonashg
34 * Cosmetic change to printouts.
36 * Revision 1.25 2002/08/21 08:15:42 jonashg
37 * Made it compile even without CONFIG_MTD_CONCAT defined.
39 * Revision 1.24 2002/08/20 13:12:35 jonashg
40 * * New approach to probing. Probe cse0 and cse1 separately and (mtd)concat
42 * * Removed compile time tests concerning how the mtdram driver has been
43 * configured. The user will know about the misconfiguration at runtime
44 * instead. (The old approach made it impossible to use mtdram for anything
45 * else than RAM boot).
47 * Revision 1.23 2002/05/13 12:12:28 johana
48 * Allow compile without CONFIG_MTD_MTDRAM but warn at compiletime and
49 * be informative at runtime.
51 * Revision 1.22 2002/05/13 10:24:44 johana
52 * Added #if checks on MTDRAM CONFIG
54 * Revision 1.21 2002/05/06 16:05:20 johana
55 * Removed debug printout.
57 * Revision 1.20 2002/05/06 16:03:00 johana
58 * No more cramfs as root hack in generic code.
59 * It's handled by axisflashmap using mtdram.
61 * Revision 1.19 2002/03/15 17:10:28 bjornw
62 * Changed comment about cached access since we changed this before
64 * Revision 1.18 2002/03/05 17:06:15 jonashg
65 * Try amd_flash probe before cfi_probe since amd_flash driver can handle two
66 * (or more) flash chips of different model and the cfi driver cannot.
68 * Revision 1.17 2001/11/12 19:42:38 pkj
69 * Fixed compiler warnings.
71 * Revision 1.16 2001/11/08 11:18:58 jonashg
72 * Always read from uncached address to avoid problems with flushing
73 * cachelines after write and MTD-erase. No performance loss have been
76 * Revision 1.15 2001/10/19 12:41:04 jonashg
77 * Name of probe has changed in MTD.
79 * Revision 1.14 2001/09/21 07:14:10 jonashg
80 * Made root filesystem (cramfs) use mtdblock driver when booting from flash.
82 * Revision 1.13 2001/08/15 13:57:35 jonashg
83 * Entire MTD updated to the linux 2.4.7 version.
85 * Revision 1.12 2001/06/11 09:50:30 jonashg
86 * Oops, 2MB is 0x200000 bytes.
88 * Revision 1.11 2001/06/08 11:39:44 jonashg
89 * Changed sizes and offsets in axis_default_partitions to use
90 * CONFIG_ETRAX_PTABLE_SECTOR.
92 * Revision 1.10 2001/05/29 09:42:03 jonashg
93 * Use macro for end marker length instead of sizeof.
95 * Revision 1.9 2001/05/29 08:52:52 jonashg
96 * Gave names to the magic fours (size of the ptable end marker).
98 * Revision 1.8 2001/05/28 15:36:20 jonashg
99 * * Removed old comment about ptable location in flash (it's a CONFIG_ option).
100 * * Variable ptable was initialized twice to the same value.
102 * Revision 1.7 2001/04/05 13:41:46 markusl
103 * Updated according to review remarks
105 * Revision 1.6 2001/03/07 09:21:21 bjornw
106 * No need to waste .data
108 * Revision 1.5 2001/03/06 16:27:01 jonashg
109 * Probe the entire flash area for flash devices.
111 * Revision 1.4 2001/02/23 12:47:15 bjornw
112 * Uncached flash in LOW_MAP moved from 0xe to 0x8
114 * Revision 1.3 2001/02/16 12:11:45 jonashg
115 * MTD driver amd_flash is now included in MTD CVS repository.
116 * (It's now in drivers/mtd).
118 * Revision 1.2 2001/02/09 11:12:22 jonashg
119 * Support for AMD compatible non-CFI flash chips.
120 * Only tested with Toshiba TC58FVT160 so far.
122 * Revision 1.1 2001/01/12 17:01:18 bjornw
123 * * Added axisflashmap.c, a physical mapping for MTD that reads and understands
124 * Axis partition-table format.
129 #include <linux/module.h>
130 #include <linux/types.h>
131 #include <linux/kernel.h>
132 #include <linux/config.h>
133 #include <linux/init.h>
135 #include <linux/mtd/concat.h>
136 #include <linux/mtd/map.h>
137 #include <linux/mtd/mtd.h>
138 #include <linux/mtd/mtdram.h>
139 #include <linux/mtd/partitions.h>
141 #include <asm/axisflashmap.h>
143 #include <asm/arch/sv_addr_ag.h>
145 #ifdef CONFIG_CRIS_LOW_MAP
146 #define FLASH_UNCACHED_ADDR KSEG_8
147 #define FLASH_CACHED_ADDR KSEG_5
149 #define FLASH_UNCACHED_ADDR KSEG_E
150 #define FLASH_CACHED_ADDR KSEG_F
154 extern unsigned long romfs_start, romfs_length, romfs_in_flash;
156 /* Map driver functions. */
158 static __u8 flash_read8(struct map_info *map, unsigned long ofs)
160 return *(__u8 *)(map->map_priv_1 + ofs);
163 static __u16 flash_read16(struct map_info *map, unsigned long ofs)
165 return *(__u16 *)(map->map_priv_1 + ofs);
168 static __u32 flash_read32(struct map_info *map, unsigned long ofs)
170 return *(volatile unsigned int *)(map->map_priv_1 + ofs);
173 static void flash_copy_from(struct map_info *map, void *to,
174 unsigned long from, ssize_t len)
176 memcpy(to, (void *)(map->map_priv_1 + from), len);
179 static void flash_write8(struct map_info *map, __u8 d, unsigned long adr)
181 *(__u8 *)(map->map_priv_1 + adr) = d;
184 static void flash_write16(struct map_info *map, __u16 d, unsigned long adr)
186 *(__u16 *)(map->map_priv_1 + adr) = d;
189 static void flash_write32(struct map_info *map, __u32 d, unsigned long adr)
191 *(__u32 *)(map->map_priv_1 + adr) = d;
195 * The map for chip select e0.
197 * We run into tricky coherence situations if we mix cached with uncached
198 * accesses to we only use the uncached version here.
200 * The size field is the total size where the flash chips may be mapped on the
201 * chip select. MTD probes should find all devices there and it does not matter
202 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
203 * probes will ignore them.
205 * The start address in map_priv_1 is in virtual memory so we cannot use
206 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
209 static struct map_info map_cse0 = {
211 .size = MEM_CSE0_SIZE,
212 .buswidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
213 .read8 = flash_read8,
214 .read16 = flash_read16,
215 .read32 = flash_read32,
216 .copy_from = flash_copy_from,
217 .write8 = flash_write8,
218 .write16 = flash_write16,
219 .write32 = flash_write32,
220 .map_priv_1 = FLASH_UNCACHED_ADDR
224 * The map for chip select e1.
226 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
227 * address, but there isn't.
229 static struct map_info map_cse1 = {
231 .size = MEM_CSE1_SIZE,
232 .buswidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
233 .read8 = flash_read8,
234 .read16 = flash_read16,
235 .read32 = flash_read32,
236 .copy_from = flash_copy_from,
237 .write8 = flash_write8,
238 .write16 = flash_write16,
239 .write32 = flash_write32,
240 .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
243 /* If no partition-table was found, we use this default-set. */
244 #define MAX_PARTITIONS 7
245 #define NUM_DEFAULT_PARTITIONS 3
248 * Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
249 * size of one flash block and "filesystem"-partition needs 5 blocks to be able
252 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
254 .name = "boot firmware",
255 .size = CONFIG_ETRAX_PTABLE_SECTOR,
260 .size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
261 .offset = CONFIG_ETRAX_PTABLE_SECTOR
264 .name = "filesystem",
265 .size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
266 .offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
270 /* Initialize the ones normally used. */
271 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
274 .size = CONFIG_ETRAX_PTABLE_SECTOR,
310 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
311 * chips in that order (because the amd_flash-driver is faster).
313 static struct mtd_info *probe_cs(struct map_info *map_cs)
315 struct mtd_info *mtd_cs = NULL;
317 printk("%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
318 map_cs->name, map_cs->size, map_cs->map_priv_1);
320 #ifdef CONFIG_MTD_AMDSTD
321 mtd_cs = do_map_probe("amd_flash", map_cs);
323 #ifdef CONFIG_MTD_CFI
325 mtd_cs = do_map_probe("cfi_probe", map_cs);
333 * Probe each chip select individually for flash chips. If there are chips on
334 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
335 * so that MTD partitions can cross chip boundries.
337 * The only known restriction to how you can mount your chips is that each
338 * chip select must hold similar flash chips. But you need external hardware
339 * to do that anyway and you can put totally different chips on cse0 and cse1
340 * so it isn't really much of a restriction.
342 static struct mtd_info *flash_probe(void)
344 struct mtd_info *mtd_cse0;
345 struct mtd_info *mtd_cse1;
346 struct mtd_info *mtd_cse;
348 mtd_cse0 = probe_cs(&map_cse0);
349 mtd_cse1 = probe_cs(&map_cse1);
351 if (!mtd_cse0 && !mtd_cse1) {
356 if (mtd_cse0 && mtd_cse1) {
357 #ifdef CONFIG_MTD_CONCAT
358 struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };
360 /* Since the concatenation layer adds a small overhead we
361 * could try to figure out if the chips in cse0 and cse1 are
362 * identical and reprobe the whole cse0+cse1 window. But since
363 * flash chips are slow, the overhead is relatively small.
364 * So we use the MTD concatenation layer instead of further
365 * complicating the probing procedure.
367 mtd_cse = mtd_concat_create(mtds,
368 sizeof(mtds) / sizeof(mtds[0]),
371 printk(KERN_ERR "%s and %s: Cannot concatenate due to kernel "
372 "(mis)configuration!\n", map_cse0.name, map_cse1.name);
376 printk(KERN_ERR "%s and %s: Concatenation failed!\n",
377 map_cse0.name, map_cse1.name);
379 /* The best we can do now is to only use what we found
383 map_destroy(mtd_cse1);
386 mtd_cse = mtd_cse0? mtd_cse0 : mtd_cse1;
393 * Probe the flash chip(s) and, if it succeeds, read the partition-table
394 * and register the partitions with MTD.
396 static int __init init_axis_flash(void)
398 struct mtd_info *mymtd;
401 struct partitiontable_head *ptable_head;
402 struct partitiontable_entry *ptable;
403 int use_default_ptable = 1; /* Until proven otherwise. */
404 const char *pmsg = " /dev/flash%d at 0x%08x, size 0x%08x\n";
406 if (!(mymtd = flash_probe())) {
407 /* There's no reason to use this module if no flash chip can
408 * be identified. Make sure that's understood.
410 panic("axisflashmap found no flash chip!\n");
413 printk("%s: 0x%08x bytes of flash memory.\n",
414 mymtd->name, mymtd->size);
416 mymtd->owner = THIS_MODULE;
418 ptable_head = (struct partitiontable_head *)(FLASH_CACHED_ADDR +
419 CONFIG_ETRAX_PTABLE_SECTOR + PARTITION_TABLE_OFFSET);
420 pidx++; /* First partition is always set to the default. */
422 if ((ptable_head->magic == PARTITION_TABLE_MAGIC)
423 && (ptable_head->size <
424 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
425 PARTITIONTABLE_END_MARKER_SIZE))
426 && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
428 PARTITIONTABLE_END_MARKER_SIZE)
429 == PARTITIONTABLE_END_MARKER)) {
430 /* Looks like a start, sane length and end of a
431 * partition table, lets check csum etc.
434 struct partitiontable_entry *max_addr =
435 (struct partitiontable_entry *)
436 ((unsigned long)ptable_head + sizeof(*ptable_head) +
438 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
440 unsigned long csum = 0;
442 ptable = (struct partitiontable_entry *)
443 ((unsigned long)ptable_head + sizeof(*ptable_head));
445 /* Lets be PARANOID, and check the checksum. */
446 p = (unsigned char*) ptable;
448 while (p <= (unsigned char*)max_addr) {
454 ptable_ok = (csum == ptable_head->checksum);
456 /* Read the entries and use/show the info. */
457 printk(" Found a%s partition table at 0x%p-0x%p.\n",
458 (ptable_ok ? " valid" : "n invalid"), ptable_head,
461 /* We have found a working bootblock. Now read the
462 * partition table. Scan the table. It ends when
463 * there is 0xffffffff, that is, empty flash.
466 && ptable->offset != 0xffffffff
468 && pidx < MAX_PARTITIONS) {
470 axis_partitions[pidx].offset = offset + ptable->offset;
471 axis_partitions[pidx].size = ptable->size;
473 printk(pmsg, pidx, axis_partitions[pidx].offset,
474 axis_partitions[pidx].size);
478 use_default_ptable = !ptable_ok;
481 if (romfs_in_flash) {
482 /* Add an overlapping device for the root partition (romfs). */
484 axis_partitions[pidx].name = "romfs";
485 axis_partitions[pidx].size = romfs_length;
486 axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
487 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
489 printk(" Adding readonly flash partition for romfs image:\n");
490 printk(pmsg, pidx, axis_partitions[pidx].offset,
491 axis_partitions[pidx].size);
495 if (use_default_ptable) {
496 printk(" Using default partition table.\n");
497 err = add_mtd_partitions(mymtd, axis_default_partitions,
498 NUM_DEFAULT_PARTITIONS);
500 err = add_mtd_partitions(mymtd, axis_partitions, pidx);
504 panic("axisflashmap could not add MTD partitions!\n");
507 if (!romfs_in_flash) {
508 /* Create an RAM device for the root partition (romfs). */
510 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
511 /* No use trying to boot this kernel from RAM. Panic! */
512 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
513 "device due to kernel (mis)configuration!\n");
514 panic("This kernel cannot boot from RAM!\n");
516 struct mtd_info *mtd_ram;
518 mtd_ram = (struct mtd_info *)kmalloc(sizeof(struct mtd_info),
521 panic("axisflashmap couldn't allocate memory for "
525 printk(" Adding RAM partition for romfs image:\n");
526 printk(pmsg, pidx, romfs_start, romfs_length);
528 err = mtdram_init_device(mtd_ram, (void*)romfs_start,
529 romfs_length, "romfs");
531 panic("axisflashmap could not initialize MTD RAM "
540 /* This adds the above to the kernels init-call chain. */
541 module_init(init_axis_flash);