[U-Boot] [PATCH 00/35][RFC] arm: socfpga: Usability fixes

[Chin Liang See]

Dear Wolfgang,

On Wed, 2014-09-17 at 16:11 +0200, ZY - wd wrote:
> Dear Chin Liang See,
> 
> In message <1410952049.7769.11.camel at clsee-VirtualBox.altera.com> you wrote:
> >
> > Hmmm... actually I can get it works well for my Altera dev kit. The
> > get_dram_size would take in the argument PHYS_SDRAM_1_SIZE. From here,
> > the function will ensure the memory specified can read and writable. If
> > its failing here, probably the SDRAM access might have issue. FYI,
> > PHYS_SDRAM_1_SIZE is 0x40000000 for 1GB.
> 
> Normally, get_dram_size() would be called with a size argument that is
> _larger_ (twice as big) as the biggest possible memory configuration
> on the respective device.  Otherwise it can only detect smaller memory
> sizes, but would fail to detect if a bigger memory device is
> installed by accident.
> 

Yup, you are right. But currently, the memory space after the SDRAM is a
bridge to FPGA. We will get data abort when trying to read that area
(for a blank FPGA). 

I believe Marek's suggestion to work around the DABT and memory
detection would work around SOCFPGA memory detection. Its something we
would work closely with Marek to enable this auto detection.

Thanks
Chin Liang

> Best regards,
> 
> Wolfgang Denk
>