Hi Wolfgang

Cannot get MTD information: Inappropriate ioctl for device got printed

Thanks Rahanesh

Wolfgang Denk wrote:

Dear Rahanesh,

In message 4AB0DFCA.4040909@tataelxsi.co.in you wrote:

...

When i executed fw_printenv on an embedded board , it threw an error

IOCTL error : Cannot get MTD information!! Any idea why this error occurred?

Well, looking in the source code, I see a single place with a similar error message:

786 rc = ioctl (fd, MEMGETINFO, &mtdinfo); 787 if (rc < 0) { 788 perror ("Cannot get MTD information"); 789 return -1; 790 }

But then, the error message would be:

Cannot get MTD information: XXX XXX XXX

with "XXX XXX XXX" giving an explanation of what goes wrong.

What was the "XXX XXX XXX" that got printed in your case?

...

The contents of config file which i used shown below

# MTD device name Device offset Env. size Flash sector size Number of sectors /dev/mtd0 0x0000 0x1000 0x10000

Are you sure this is correct? Your environment size is only 4 KiB? And your flash secor size is 64 KiB?

Best regards,

Wolfgang Denk

Dear Wolfgang,

Well, that most certainly means that your /dev/mtd0 is not a NOR or NAND flash device.

I use mtd_debug utility to identify the /dev/mtd0 device. It said it is Nor flash.

Thanks Rahanesh

Hi Rahanesh,

...

Well, that most certainly means that your /dev/mtd0 is not a NOR or NAND flash device.

   Now used the fw_printenv under tools/env directory of uboot. It 

does not have IOCTL error.

    On issuing a fw_printenv it showd following messages

     Bad data CRC, Using default environment and printed only few 

environment variables.

This should have made big warning signs flash up - if data crc was not correct, it was 99% sure that your configuration wasn't ok.

      Then i did a fw_setenv bootdelay 6. It showed some messgaes of 

erasing flash. But it actually erased my uboot itself.

No big wonder here.

      What might be the issue? config file?

Of course.

       MTD device name   Device offset   Env. size        Flash 

sector size Number of sectors /dev/mtd0 0x0000 0x1000 0x10000

What does Device Offset mean?

Offset is the offset into the area mapped by the device file.

/dev/mtd0 has both uboot as well as environment variables. Environment variables lie at bottom of /dev/mtd0. Is that the meaning of device offset?

That would be the meaning. You can always test by reading /dev/mtd0 directly from linux and inspect its contents, i.e. try

dd if=/dev/mtd0 bs=64k count=1 | hexdump -C | less

(or something comparable) and look for your environment.

#define CFG_ENV_ADDR 0xAD03F000 (Flash starts at 0xAD000000) #define CFG_ENV_SIZE 0x1000 #define CFG_ENV_SECT_SIZE 0x10000

These are the macro that i found in include/configs/board.h

This looks completly weird to me. Can you tell me exactly what board you are working with? It looks like this cannot be a NOR flash..

Cheers Detlev