Hi Albert,
On 20.06.2013 18:42, Albert ARIBAUD wrote:
>> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
>> index a9657d1..b05f66a 100644
>> --- a/arch/arm/lib/crt0.S
>> +++ b/arch/arm/lib/crt0.S
>> @@ -85,7 +85,13 @@ ENTRY(_main)
>> bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
>> sub sp, #GD_SIZE /* allocate one GD above SP */
>> bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
>> +#if !defined(CONFIG_SPL_BUILD)
>> +/*
>> + * SPL already has GD set to the correct location (in s_init), we mustn't
>> + * move it around now since some data (clocks etc) is already present.
>> + */
>> mov r8, sp /* GD is above SP */
>> +#endif
>> mov r0, #0
>> bl board_init_f
>>
>
> NAK in this form. I don't want gd to be set "somewhere in the code"
> depending on the actual target; I want it set in crt0.S, period.
>
> I see there are several locations in ARM architecture or board code
> which set up GD themselves in the same manner as OMAP does. Luckily all
> these locations set it to the same value, the address of gdata.
>
> The correct fix (read: the one I won't NAK) is thus to add a #else
> clause in the code above, in which r8 will be set to =gdata, and to
> remove the corresponding assignments in the various places where they
> reside.
Here's the problem. Setting r8 in _main is too late. As it has already
been used (in the current implementation) to store some data (e.g.
clocks for baudrate generation etc). Here the code from
arch/arm/cpu/armv7/omap3/board.c:s_init():
#ifdef CONFIG_SPL_BUILD
gd = &gdata;
preloader_console_init();
timer_init();
#endif
Note that this is done *before* _main() is called (we are talking about
SPL for OMAP here). And it did cost me quite some time to find this
problem, that r8 was re-configured in _main() and all the already set
values disappeared again (no serial output etc).
Yes, this needs some cleanup/fixup. Unfortunately I won't find the time
to look into such a cleanup in the next days. Perhaps somebody else
might jump in...
Thanks,
Stefan
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