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,