[Arm-netbook] rev0 a10 eoma68 board bringup

[luke.leighton]

On Sat, Dec 22, 2012 at 2:20 AM, Henrik Nordström
<henrik at henriknordstrom.net> wrote:
> fre 2012-12-21 klockan 22:15 +0000 skrev luke.leighton:
>
>>  it's going into FEL mode all right - it's that when it's in FEL mode
>> and you plug it in you get "USB device not accepting address, error
>> -77" or something like that, which is a definite "oops".
>
> Hmm.. have maybe d+/d- been switched?

 they were.  they're not any more.  i've tried flipping them.  nothing
when inverted.  response when put correct way round - just failing to
accept the USB address.

> Or shorted?

 no.  both of them show a signal.

> Or perhaps connected to the wrong pins?

 i've checked the gerbers: they're to the correct wires.

> The only parameters FEL should depend on are
> - Sufficient CPU voltage
> - Correct 3.3V I/O voltage
> - Correct clock crystal frequency

 yeah.  that's not hard!

>>  what i'm going to do is to use this to find out the point at which
>> loading is failing.  keep moving the GPIO set to a point in the code
>> where it stops happening.  repeat and use binary search to find the
>> function which goes tits-up.
>
> No sign of life from the UART either?

none.

> sunxi-current u-boot SPL activates UART very early. If that too is
> failing then it is not a good sign.

 it's hard to tell if it's "failing" when there's no response at all.
bear in mind i can only use UART3.

 my guess is that the chip's shutting down very very quickly, like
after a second or so.

 i'm going to try setting virtually every pin to INPUT (is there a way
to set them tri-state?) and see what happens.

l.