[U-Boot] [SOLVED] Strange / Unreadable console output

Andreas Bießmann andreas.devel at googlemail.com
Thu Aug 16 19:30:31 CEST 2012


On 16.08.2012 18:51, Markus Hubig wrote:
> Hi Andreas,
> 
> On Thu, Aug 16, 2012 at 05:33:26PM +0200, Andreas Bießmann wrote:
>> On 16.08.2012 17:07, Markus Hubig wrote:
> 
> <snip>
> 
>>> But it definitly dosn't work here. I checked with an oscilator, if I toggle
>>> the pin in board_init() I can nicely see it going high and low but if I
>>> toggle it in board_early_init_f() *nothing* happens!
>>
>> Well as mentioned in my mail the mdelay() can not work in
>> board_eraly_init_f() cause the timers are not setup at this stage. You
>> need to provide some nop-loop based delay here to have proper delay!
>> As mentioned before my at91sam9263 (running at about 200 MHz produce 38
>> us out of a mdelay(10); I dunno what your g20 variant with about 400 MHz
>> produces here). A simple test could be to move the timer init in
>> a/a/lib/board.c before board_early_init_f in the init_sequence. Then the
>> mdelay() will work as expected!
> 
> You were right! The problem was the missing delay after setting the pin!
> Just moving the timer_init() before board_early_init_f() in the init_sequence
> didn't work because we need the clocks from board_early_init_f() first. But I
> found the
> 
> | board_postclk_init()
> 
> function and the corresponding
> 
> | CONFIG_BOARD_POSTCLK_INIT
> 
> switch, so I put everything there and now it all works fine! ;-)  

great!

>> send a patch (including working serial console output ;)
> 
> Unfortunately the board_postclk_init() function was not in the init_sequence
> at arch/arm/lib/board.c so I added it there. I will provide two patches, one
> for the board stuff and one for the stamp stuff, if this is OK with you ...

I think adding the postclock stuff to arm is ok. Albert is responsible
for that so if he is willing to accept that the stamp9g20 stuff is no
problem.

Best regards

Andreas Bießmann


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