Hello All,

My board has one 16-bit flash: ST M29W640DB.

M29W640DB (16 bit bus):

0x00000000-0x00700000 : "Root"

0x00700000-0x00720000 : "U-Boot Bootloader"

0x00720000-0x01000000 : "Linux Kernel"

When power on, Linux kernel boots from flash and print out info such as:

"

..............................................

PPP generic driver version 2.4.2

..............................................

EP8248 flash map (size->0x800000 mem->0xFF800000)

Amd/Fujitsu Extended Query Table v1.3 at 0x0040

number of CFI chips: 1

cfi_cmdset_0002: Disabling fast programming due to code brokenness.

Creating 3 MTD partitions on "EP8248 flash memory":

0x00000000-0x00700000 : "Root"

0x00700000-0x00720000 : "U-Boot Bootloader"

0x00720000-0x01000000 : "Linux Kernel"

......................................

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00060000: 0x0020 instead

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00060004: 0x22df instead

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0006000c: 0x0008 instead

Further such events for this erase block will not be printed

................................................................

Further such events for this erase block will not be printed

JFFS2: Erase block at 0x003a0000 is not formatted. It will be erased

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x003c0000: 0x0020 instead

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x003c0004: 0x22df instead

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x003c000c: 0x0008 instead

Further such events for this erase block will not be printed

JFFS2: Erase block at 0x003c0000 is not formatted. It will be erased

....................................................................

....................................................................

"

In u-boot, I entered commands to display memory:

u-boot=> md 0xff000000

The magic number 0x1985 IS here!No 0x0020 exists at all!!

It's quite strange!! Why Linux detects 0x0020 instead?

Why U-boot can read the data on flash correctly while linux can't?

Why linux always read all data as 0x0020?

When I simply replace ST M29W640DB with AMD AM29DL640D (the two chips are

pin-to-pin compatible,) JFFS2 works very fine!

What's the problem?

I don't want to use AMD FLASH, can u suggest me what necessary changes are to be made in the code so that the ST M29W640DB Flash work,

Regards,

VB

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