[U-Boot] md,mw commands

[albert.u.boot at aribaud.net]

Hi V.Balaji,

Le 2012-03-06 10:41, VISWANADHULA BALAJI a écrit :
> Hi,
>
>     Iam  using 256MB RAM on arm11 board.I just tried md,mw commands 
> from
> uboot like the following
>
> mw C800000 0xbbbbbbbb 0x500       here C800000 is the 200MB of RAM
>
> MCS8142>> md C800000
> 0c800000: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800010: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800020: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800030: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800040: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800050: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800060: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800070: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800080: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c800090: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c8000a0: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c8000b0: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c8000c0: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c8000d0: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c8000e0: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
> 0c8000f0: bbbbbbbb bbbbbbbb bbbbbbbb bbbbbbbb    ................
>
> mw  32000000 0xffffffff  0x500  here 32000000 is the 800MB of RAM
>
> MCS8142>> md 32000000
> 32000000: ffffffff ffffffff ffffffff ffffffff    ................
> 32000010: ffffffff ffffffff ffffffff ffffffff    ................
> 32000020: ffffffff ffffffff ffffffff ffffffff    ................
> 32000030: ffffffff ffffffff ffffffff ffffffff    ................
> 32000040: ffffffff ffffffff ffffffff ffffffff    ................
> 32000050: ffffffff ffffffff ffffffff ffffffff    ................
> 32000060: ffffffff ffffffff ffffffff ffffffff    ................
> 32000070: ffffffff ffffffff ffffffff ffffffff    ................
>
>
> How it is possible to see the data even after the 256MB of RAM.If i 
> give
> the sizes like 256MB ,512MB mw command get hangs otherwise the data 
> is
> writing to the RAM even the size exceeds the size of actual RAM. 
> Please
> help me.

Did you check the configuration of your board's memory controller, 
especially how "chip select" mechanism is mapped onto ARM11 address 
space?

A bad configuration can mirror the actual 256 MB several times over a 
bigger area -- so address 0 of your RAM would be seen at ARM11 address 
0, but also 0x10000000, 0x20000000, etc.

A quick check would be to write something at 0x10000000 and then read 
0x20000000, and see if it mirrors 0x10000000.

> Thanks
> V.Balaji

Amicalement,
-- 
Albert.