[U-Boot] ppc405ep boot freeze with u-boot 1.3.4

[Stefan Roese <sr@denx.de>]

Hi Reto,

On Friday 21 November 2008, Reto Stalder wrote:
> I have a custom ppc405ep board with 128MB SDRAM, very similar to the
> AMCC Taihu board. U-Boot 1.1.4 works perfectly fine. But version 1.3.4
> freezes after saying "Relocating now" in debug mode.

This is an indication of an SDRAM initialization problem.

> Additionally, I've observed a strange effect concerning memory size:
> When a BDI2000 emulator is connected and the SDRAM size is set to 64MB
> or less, the board starts to the prompt. When a BDI2000 emulator is
> connected and the SDRAM size is set to 128MB, it freezes as well.

What does this mean: "the SDRAM size is set to 64MB"? Who *set's* the SDRAM 
size? Does the board do an SDRAM size autodetection? Which SDRAM init code is 
used? You probably don't reset the SDRAM controller after running an SDRAM 
initialization from the BDI2000. How do you start via the BDI2000? 
With "reset run"? Or differently?

> Has somebody any ideas, where the problem could reside, or what else to
> do, to isolate the problem?
>
> Every comment is welcome ;-),

Even 1.3.4 is old. I suggest that you give the latest git version a try. And 
please use the code in cpu/ppc4xx/sdram.c to init the SDRAM controller. How 
many SDRAM banks do you use? 1 or 2? If you use two then you need to enable 
both banks via those config options:

/*
 * SDRAM configuration (please see cpu/ppc/sdram.[ch])
 */
#define CONFIG_SDRAM_BANK0      1       /* init onboard SDRAM bank 0 */
#define CONFIG_SDRAM_BANK1      1       /* init onboard SDRAM bank 1 */
...

Please see taihu.h or zeus.h as a reference. This should help.

Best regards,
Stefan

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