[U-Boot] [RFC PATCH 1/5] armv7: move boot hook before '_start'

[Marek Vasut]

On 06/13/2017 11:44 AM, Dr. Philipp Tomsich wrote:
> Marek,
> 
>> On 13 Jun 2017, at 10:42, Marek Vasut <marex at denx.de
>> <mailto:marex at denx.de>> wrote:
>>
>> On 06/13/2017 03:51 AM, Kever Yang wrote:
>>> Hi Marek,
>>
>> Hi,
>>
>>> On 06/07/2017 02:28 PM, Marek Vasut wrote:
>>>> On 06/07/2017 04:28 AM, Kever Yang wrote:
>>>>> Hi Andre, Steve, Marek,
>>>>>
>>>>>     Could you help to check how to make it work with this patch on
>>>>> sunxi, bcm and socfpga platform?
>>>> The socfpga expects the hook at that exact position (0x40 I think) , so
>>>> if you moved it somewhere, you broke socfpga.
>>>
>>> I know this break socfpga, and that's why I cc you for help, could you
>>> help the take a look if we can have a solution on socfpga to "make it
>>> work with this patch"?
>>
>> Can you generate the same u-boot binary with this patch ? If so, then it
>> will work on socfpga. SoCFPGA expects that small piece of stuff at
>> offset 0x40 , so if you move this boot0 hook, it will break. HTH
> 
> So the SoCFPGA-implementation relies on the boot0 hook to always start
> at 0x40?  Then this needs fixing anyway… or it will break once someone
> else touches the armv7 startup code.

I think it's not just the SoCFPGA.

> That said, I read your comment to mean that the following changes would
> work for SoCFPGA:
> 1.arch/arm/lib/vectors.S:
> #if CONFIG_IS_ENABLED(BOOT0_HOOK)
> … pull in the boot0 hook, which needs to contain the vectors
> #else
> b reset
> … remaining vectors … 
> #endif
> 2.boot0.h (for socfpga):
> b reset
> … remaining vectors …
> /* now at 0x40 */
> … whatever currently lives in the boot0.h for socfpga ...
> 
> Ok?

I'm not sure I understand what you're trying to say. IIRC the SoCFPGA
bootrom checks the content at 0x40-0x48 in SRAM and then jumps to 0x50
if the content is valid. Otherwise it reloads the content from
SD/SPI/NAND...

[...]

btw can you please disable the HTML email ?

-- 
Best regards,
Marek Vasut