My router has 8GB DDR what config need to change in UBOOT to access 8GB

[ramakrishnakatt]

we are using powerpc-fsl_networking-linux-gcc? is this sufficient or we need to use 64bit power pc compiler.

[LPP]

36-bit address mode is required to support physical memory larger than 4GB

Please refer to Section 6.1.3 U-boot Configuration of the following document:

Freescale Linux SDK for QorIQ Processors

http://cache.freescale.com/files/soft_dev_tools/doc/support_info/QorIQ-SDK-1.7-IC-RevB.zip

Have a great day,
Pavel

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[ramakrishnakatt]

Hi Pavel,

Thanks for your information, but in our current uboot code i did not find any config files with name T1040RDB_36BIT_config

Can you point out the config file for 36-bit access in Uboot

Thanks

Rama

[scottwood]

T1040 U-Boot always supports 36-bit addressing.  You don't need to do anything special.

[ramakrishnakatt]

Hi Scott,

Our requirement is to test Uboot higher address, we can't  able to access higher address from Uboot prompt.

if we want access, 0xfe0000000, from uboot prompt how we will access?

if we try to dump with md command it is displaying only 0xe0000000,, what is the solution, what things we have to change to make 36-bit access

[scottwood]

FWIW, 0xfe0000000 is CCSR which is mapped to virtual 0xe0000000, so you can use md for that.  You just can't access DDR above 2 GiB.

[scottwood]

U-Boot on PPC always runs in 32-bit mode, so it can't address that extra RAM itself.  To access it, you need to load an OS, or write a standalone application or custom U-Boot code that creates temporary TLB mappings to access it in chunks.