[Yaffs1] mkyaffs exits with "MTD Erase failure"
Martin Egholm Nielsen
martin at egholm-nielsen.dk
Wed Jun 6 08:06:31 EDT 2007
Hi,
Ricard Wanderlof wrote:
> On Mon, 4 Jun 2007, Martin Egholm Nielsen wrote:
>>>>So, I fixed the timing in the kernel and tried erasing the flash
>>>>again. But with no luck - mkyaffs refuses to erase/program the
>>>>flash:
>>>Mtd refuses to erase blocks that have been marked bad. There is no
>>>workaround on a running kernel, but it is possible to patch the
>>>kernel to do this.
>>But as you see, flash_eraseall on the same device works perfectly fine:
>>flash_eraseall /dev/mtd0
>>....
>>Skipping bad block at 0x0179c000
>>Erasing 16 Kibyte @ 1ffc000 -- 99 % complete.
> flash_eraseall skips bad blocks while erasing. I don't know how mkyaffs
> works though.
Well, glancing at the code, it should be doing something like it:
==== ORIGINAL mkyaffs.c ====
for(addr = 0; addr < meminfo.size; addr += meminfo.erasesize)
{
/* Read the OOB data to determine if the block is valid.
* If the block is damaged, then byte 5 of the OOB data will
* have at least 2 zero bits.
*/
oob.start = addr;
oob.length = 16;
oob.ptr = oobbuf;
if (ioctl(fd, MEMREADOOB, &oob) != 0)
{
perror("ioctl(MEMREADOOB)");
close(fd);
exit(1);
}
if(countBits[oobbuf[5]] < 7)
{
printf("Block at 0x08%lx is damaged and is not being
formatted\n",addr);
}
=======================
However, it doesn't seem to do the trick. So I copied the check from
"flash_eraseall" and put in, as well:
==== NEW mkyaffs.c ====
for(addr = 0; addr < meminfo.size; addr += meminfo.erasesize)
{
/* MEN 2007-06-06 */
loff_t bah = addr;
int ret = ioctl(fd, MEMGETBADBLOCK, &bah);
if (ret > 0)
{
printf( "Block at 0x08%lx would have been ignored by
flash_eraseall!\n", addr );
continue;
} // if
// OLD CODE HERE
=======================
And now it seems to work:
# mkyaffs-hacked-2007-06-06 -e /dev/mtd0
argc 3 sh 0 optcnt 2
Erasing and programming NAND
Erasing block at 0x080
Erasing block at 0x084000
...
Erasing block at 0x0898000
Block at 0x089c000 would have been ignored by flash_eraseall!
....
So that's good!? Unless there is a reason why that check was not there
originally!
Charles Manning, do you care for a comment?
> You can always re-mark the factory bad ones, given that you have written
> down which they were once... if you are using a flash-based BBT, erasing
> the BBT blocks would suffice, as the bad block management in jffs2 when
> using a flash-based BBT doesn't touch bad block markers. I would assume
> from your reasoning that you are not using a flash-based BBT?
I don't, no. And I didn't write down the factory ones...
BR,
Martin
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