本文针对uboot较新版本uboot-2009进行，nand flash page(512+16)，
方法：跟踪nand write命令即可，需要修改一定是沿途被调用过的命令
uboot本身并没有支持yaffs文件系统烧写，在此我们自己添加：
1.命令部分
common/cmd_nand.c
U_BOOT_CMD(nand, CONFIG_SYS_MAXARGS, 1, do_nand,
"NAND sub-system",
"info - show available NAND devices/n"
"nand device [dev] - show or set current device/n"
"nand read - addr off|partition size/n"
"nand write - addr off|partition size/n"
" read/write 'size' bytes starting at offset 'off'/n"
" to/from memory address 'addr', skipping bad blocks./n"
"nand erase [clean] [off size] - erase 'size' bytes from/n"
" offset 'off' (entire device if not specified)/n"
#if defined(ENABLE_CMD_NAND_YAFFS)
"nand read[.yaffs[1]] is not provide temporarily!/n"
"nand write[.yaffs[1]] addr off size - write the `size' byte yaffs image starting/n"
" at offset `off' from memory address `addr' (.yaffs1 for 512+16 NAND)/n"
#endif
"nand bad - show bad blocks/n"
"nand dump[.oob] off - dump page/n"
"nand scrub - really clean NAND erasing bad blocks (UNSAFE)/n"
"nand markbad off [...] - mark bad block(s) at offset (UNSAFE)/n"
"nand biterr off - make a bit error at offset (UNSAFE)"
#ifdef CONFIG_CMD_NAND_LOCK_UNLOCK
"/n"
"nand lock [tight] [status]/n"
" bring nand to lock state or display locked pages/n"
"nand unlock [offset] [size] - unlock section"
#endif
);
2.源码部分
common/cmd_nand.c
函数：do_nand()
if (strncmp(cmd, "read", 4) == 0 || strncmp(cmd, "write", 5) == 0) {
int read;
if (argc < 4)
goto usage;
addr = (ulong)simple_strtoul(argv[2], NULL, 16);
read = strncmp(cmd, "read", 4) == 0; /* 1 = read, 0 = write */
printf("/nNAND %s: ", read ? "read" : "write");
if (arg_off_size(argc - 3, argv + 3, nand, &off, &size) != 0)
return 1;
s = strchr(cmd, '.');
if (!s || !strcmp(s, ".jffs2") ||
!strcmp(s, ".e") || !strcmp(s, ".i")) {
if (read)
ret = nand_read_skip_bad(nand, off, &size,
(u_char *)addr);
else
ret = nand_write_skip_bad(nand, off, &size,
(u_char *)addr);
#if defined(ENABLE_CMD_NAND_YAFFS)
}else if ( s != NULL &&
(!strcmp(s, ".yaffs") || !strcmp(s, ".yaffs1"))){
if(read) {
printf("nand read.yaffs[1] is not provide temporarily!");
} else {
nand->rw_oob = 1;
#if defined(ENABLE_CMD_NAND_YAFFS_SKIPFB)
nand->skipfirstblk = 1;
#else
nand->skipfirstblk = 0;
#endif
ret = nand_write_skip_bad(nand,off,&size,(u_char *)addr);
#if defined(ENABLE_CMD_NAND_YAFFS_SKIPFB)
nand->skipfirstblk = 0;
#endif
nand->rw_oob = 0;
}
#endif
} else if (!strcmp(s, ".oob")) {
/* out-of-band data */
mtd_oob_ops_t ops = {
.oobbuf = (u8 *)addr,
.ooblen = size,
.mode = MTD_OOB_RAW
};
if (read)
ret = nand->read_oob(nand, off, &ops);
else
ret = nand->write_oob(nand, off, &ops);
} else {
printf("Unknown nand command suffix '%s'./n", s);
return 1;
}
printf(" %zu bytes %s: %s/n", size,
read ? "read" : "written", ret ? "ERROR" : "OK");
return ret == 0 ? 0 : 1;
}
---------------------------------------------------------------------------------------------------------------------------------
include/linux/mtd/mtd.h
struct mtd_info {
u_char type;
u_int32_t flags;
uint64_t size; /* Total size of the MTD */
/* "Major" erase size for the device. Na飗e users may take this
* to be the only erase size available, or may use the more detailed
* information below if they desire
*/
u_int32_t erasesize;
/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
* though individual bits can be cleared), in case of NAND flash it is
* one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
* it is of ECC block size, etc. It is illegal to have writesize = 0.
* Any driver registering a struct mtd_info must ensure a writesize of
* 1 or larger.
*/
u_int32_t writesize;
#if defined(ENABLE_CMD_NAND_YAFFS)
/*Thanks for hugerat's code*/
u_char rw_oob;
u_char skipfirstblk;
#endif
u_int32_t oobsize; /* Amount of OOB data per block (e.g. 16) */
u_int32_t oobavail; /* Available OOB bytes per block */
/* Kernel-only stuff starts here. */
const char *name;
int index;
/* ecc layout structure pointer - read only ! */
struct nand_ecclayout *ecclayout;
/* Data for variable erase regions. If numeraseregions is zero,
* it means that the whole device has erasesize as given above.
*/
int numeraseregions;
struct mtd_erase_region_info *eraseregions;
------------------------------------------------------------------------------------------------------------------------------
drivers/mtd/nand/nand_base.c
static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const uint8_t *buf)
{
struct nand_chip *chip = mtd->priv;
int ret;
#if defined(ENABLE_CMD_NAND_YAFFS)
int oldopsmode = 0;
if(mtd->rw_oob==1) {
size_t oobsize = mtd->oobsize;
size_t datasize = mtd->writesize;
int i = 0;
uint8_t oobtemp[oobsize];
int datapages = 0;
datapages = len/(datasize);
for(i=0;i<(datapages);i++) {
memcpy((void *)oobtemp,
(void *)(buf+datasize*(i+1)),
oobsize);
memmove((void *)(buf+datasize*(i+1)),
(void *)(buf+datasize*(i+1)+oobsize),
(datapages-(i+1))*(datasize)+(datapages-1)*oobsize);
memcpy((void *)(buf+(datapages)*(datasize+oobsize)-oobsize),
(void *)(oobtemp),
oobsize);
}
}
#endif
/* Do not allow reads past end of device */
if ((to + len) > mtd->size)
return -EINVAL;
if (!len)
return 0;
nand_get_device(chip, mtd, FL_WRITING);
chip->ops.len = len;
chip->ops.datbuf = (uint8_t *)buf;
#if defined(ENABLE_CMD_NAND_YAFFS)
if(mtd->rw_oob!=1) {
chip->ops.oobbuf = NULL;
} else {
chip->ops.oobbuf = (uint8_t *)(buf+len);
chip->ops.ooblen = mtd->oobsize;
oldopsmode = chip->ops.mode;
chip->ops.mode = MTD_OOB_RAW;
}
#else
chip->ops.oobbuf = NULL;
#endif
ret = nand_do_write_ops(mtd, to, &chip->ops);
*retlen = chip->ops.retlen;
nand_release_device(mtd);
#if defined(ENABLE_CMD_NAND_YAFFS)
chip->ops.mode = oldopsmode;
#endif
return ret;
}
--------------------------------------------------------------------------------------------------------------------
drivers/mtd/nand/nand_util.c
int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
u_char *buffer)
{
int rval;
size_t left_to_write = *length;
size_t len_incl_bad;
u_char *p_buffer = buffer;
#if defined(ENABLE_CMD_NAND_YAFFS)
if(nand->rw_oob==1) {
size_t oobsize = nand->oobsize;
size_t datasize = nand->writesize;
int datapages = 0;
if (((*length)%(nand->oobsize+nand->writesize)) != 0) {
printf ("Attempt to write error length data!/n");
return -EINVAL;
}
datapages = *length/(datasize+oobsize);
*length = datapages*datasize;
left_to_write = *length;
// nand->skipfirstblock=1;
}
#endif
/* Reject writes, which are not page aligned */
if ((offset & (nand->writesize - 1)) != 0 ||
(*length & (nand->writesize - 1)) != 0) {
printf ("Attempt to write non page aligned data/n");
return -EINVAL;
}
len_incl_bad = get_len_incl_bad (nand, offset, *length);
if ((offset + len_incl_bad) > nand->size) {
printf ("Attempt to write outside the flash area/n");
return -EINVAL;
}
#if !defined(ENABLE_CMD_NAND_YAFFS)
if (len_incl_bad == *length) {
rval = nand_write (nand, offset, length, buffer);
if (rval != 0)
printf ("NAND write to offset %llx failed %d/n",
offset, rval);
return rval;
}
#endif
while (left_to_write > 0) {
size_t block_offset = offset & (nand->erasesize - 1);
size_t write_size;
WATCHDOG_RESET ();
if (nand_block_isbad (nand, offset & ~(nand->erasesize - 1))) {
printf ("Skip bad block 0x%08llx/n",
offset & ~(nand->erasesize - 1));
offset += nand->erasesize - block_offset;
continue;
}
#if defined(ENABLE_CMD_NAND_YAFFS)
if(nand->skipfirstblk==1) {
nand->skipfirstblk=0;
printf ("Skip the first good block %llx/n",
offset & ~(nand->erasesize - 1));
offset += nand->erasesize - block_offset;
continue;
}
#endif
if (left_to_write < (nand->erasesize - block_offset))
write_size = left_to_write;
else
write_size = nand->erasesize - block_offset;
printf("/rWriting at 0x%llx -- ",offset); /*Thanks for hugerat's code*/
rval = nand_write (nand, offset, &write_size, p_buffer);
if (rval != 0) {
printf ("NAND write to offset %llx failed %d/n",
offset, rval);
*length -= left_to_write;
return rval;
}
left_to_write -= write_size;
printf("%d%% is complete.",100-(left_to_write/(*length/100)));/*Thanks for hugerat's code*/
offset += write_size;
#if defined(ENABLE_CMD_NAND_YAFFS)
if(nand->rw_oob==1) {
p_buffer += write_size+(write_size/nand->writesize*nand->oobsize);
} else {
p_buffer += write_size;
}
#else
p_buffer += write_size;
#endif
}
return 0;
}
3.添加配置
为了支持write.yaffs命令，在板子的配置头文件中添加：
#define ENABLE_CMD_NAND_YAFFS 1
#define ENABLE_CMD_NAND_YAFFS_SKIPFB 1
即可
4.使用
烧写yaffs文件系统时，只要nand write.yaffs 即可
