[U-Boot] Can't erase or read NOR using mtd part-id

[Alexandre Gambier <a.gambier@ftemaximal.fr>]

Dear Wolfgang,

Thanks for this explanation.

Best regards
Alex

On 02/09/2011 07:50 PM, Wolfgang Denk wrote:
> Dear Alexandre Gambier,
>
> In message<4D52B843.5010004@ftemaximal.fr>  you wrote:
>> I'm using u-boot to boot a Linux-based device.
>> I created some MTD partitions for my NOR and NAND flashes.
>>
>> Here is the configuration:
>>
>> device nor0<NOR>, # parts = 4
>>    #: name                        size            offset          mask_flags
>>    0: U-Boot              0x00080000      0x00000000      0
>>    1: Environment         0x00020000      0x00080000      0
>>    2: Kernel              0x00400000      0x000a0000      0
>>    3: FreeNOR             0x00360000      0x004a0000      0
>>
> ...
>> When I want to erase the U-Boot partition I can't use the command `erase
>> U-Boot`, the following error occurs : "incorrect device type in U-Boot".
>> I must use the command `erase 1:0-7`.
>>
>> Is-it normal ?
> There are many ways to specify a flash area. When referring to MTD
> partitions, the synatx is "<device name>,<partition number>", i. e.
> for the partition named "U-Boot" above you use
>
> 	erase nor0,0
>
> So yes, the behaviour is normal.
>
>> My second question is when I try to read the Environment partition with
>> the command `md.b Environment 128` I get the following dump (which is
>> not correct).
>>
>> 0000000e: 0e 40 ff e0 18 40 c0 cb 18 40 18 40 0c cb 03 61
>> . at ...@... at .@...a
> ...
>
> Only very few commands (and only flash related ones) accept MTD
> partition specifications for addresses.  "md" does not. What happpens
> here is that the argument "Environment" gets parsed as a hex number.
> Only the first character, 'E', can successfully be converted, then the
> conversion stops (without error message).  Then you get the dump
> starting at 0x0000000E.
>
>> Is-it normal as well ?
> Yes, it is.
>
> Best regards,
>
> Wolfgang Denk
>