[U-Boot] T4QDS e6500 core and U-Boot 64-bit

[York Sun <yorksun@freescale.com>]

On 01/25/2014 07:46 AM, Timur Tabi wrote:
> On Fri, Jan 24, 2014 at 7:45 AM, Wolfgang Denk <wd@denx.de> wrote:
>>
>> For the "test"
>> part, it is probably much easier to add a customized memory test (or
>> fix just the existing memory test such that it can be built for a 64
>> bit mode) and use this, then trying to run all of U-Boot in 64 bit
>> mode.
> 
> There already is PowerPC memory test code in U-Boot that supports more
> than 2GB.  It uses sliding TLB windows.  If it doesn't already support
> 12GB, then it should be easy to add that support.

If the target is to test memory, current u-boot supports 36-bit address to cover
64GB memory. As everybody explained, only 2GB is "visible" at a time. But
actually all memory are read to use (by Linux or other OS). The POST memory test
slides the 2GB window to cover all DDR. It will remap back the window, as you
would see the message on the console.

York