[U-Boot] i.MX35PDK: Starting U-Boot from serial NOR-Flash

[Stefano Babic <sbabic@denx.de>]

On 03/08/2012 10:03, Michael Hornung wrote:
> Hi Fabio,
> 

Hi Michael,

>>>
>>
>> Didn't you also had to remove the init_sdram call in lowlevel_init.S ?
>>
> 
> No, I didn't change it since it seems not to make any difference. Hope
> we're talking about the same, I changed the following and it did not
> make any difference whether it was commented or not:
> 
> +++ b/board/freescale/mx35pdk/lowlevel_init.S
> 
>  init_sdram_start:
>         /*init_sdram*/
> -       setup_sdram
> +/*     setup_sdram */
> 

Because the RAM is already set up via the imximage.

> 
>>>
>>> Then I did the following change:
>>>
>>> +++ b/board/freescale/mx35pdk/mx35pdk.c
>>>
>>>         size1 = get_ram_size((void *)PHYS_SDRAM_1, PHYS_SDRAM_1_SIZE);
>>> -       size2 = get_ram_size((void *)PHYS_SDRAM_2, PHYS_SDRAM_2_SIZE);
>>> +        size2 = 0;
>>> +       /*size2 = get_ram_size((void *)PHYS_SDRAM_2, PHYS_SDRAM_2_SIZE);*/
>>
>> I think we should not touch this.
>>
> 
> Hey, but it works (halfways) :-)

It depends on your mx35pdk. The board can be equipped with one or two
banks. If it works commenting these lines, it means that in your
imximage.cfg you set only one bank. The setup_sdram() sets both banks.


>>> Could you please give me some hits what to do next?
>>
>> Can you please try to remove  #define CONFIG_ENV_IS_IN_FLASH and insert:
>>
>> #define CONFIG_SYS_NO_FLASH
>>
>> #define CONFIG_ENV_OFFSET      (6 * 64 * 1024)
>> #define CONFIG_ENV_SIZE        (8 * 1024)
>> #define CONFIG_ENV_IS_IN_MMC
>> #define CONFIG_SYS_MMC_ENV_DEV
> 
> A first quick try ended up with the following (I'll try harder today:

Mmhh...you had already a running u-boot - your problem is moved, because
the kernel is not correctly started.

I think you should start from this condition (the running u-boot) and
try to understand where the kernel hangs. This can be of course
something related to u-boot and in u-boot code, but trying to disable
things that worked can be completelky unrelated.

By the way, if you set CONFIG_SYS_NO_FLASH, you should also set that the
environment is embedded (that means, you have only the default) and
deactivate the flash driver (CONFIG_CFI).

Best regards,
Stefano Babic


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