[Arm-netbook] a10 eoma68 cpu card bring-up

[mike.valk at gmail.com]

2013/5/15 luke.leighton <luke.leighton at gmail.com>:
> On Wed, May 15, 2013 at 2:46 PM, mike.valk at gmail.com
> <mike.valk at gmail.com> wrote:
>> 2013/5/15 luke.leighton <luke.leighton at gmail.com>:
>>
>> Congratulations Luke, et al.
>>
>>> On Wed, May 15, 2013 at 11:16 AM, joem <joem at martindale-electric.co.uk> wrote:
>>>
>>>> Congratulations Luke!!!!!!!!!!
>>>>
>>>> You manage to thread a fine needle through all the hardware and
>>>> software, issue after issue, step by step, until you have finally a
>>>> bootable EOMA. :)
>>>
>>>  still am going through repro'ing henrik's kernel compile, all good
>>> fun because this revision of the board doesn't have JTAG.  don't ask.
>>> really.  just... don't ask :)
>>
>> Err. Not even a serial (UART) interface?
>
>  only by accident.
>
>> Suggestion for the next iteration of the board. Add an extra micro-sd
>> slot.
>
>  yes.  except that requires case rework, which will be an extra $10k.

I thought to put it on the bottom side of the outside facing side.
We're using two midmount connectors and a top mount micro-sd.

      MicroSD
-HDMI---------USB-
      MicroSD

I know very simplistic though, I understand that the PCB is crowded
with traces already.

>
>> Some of the benfits.
>> 1. Boot from removable storage. While keeping a swappable storage available
>> 2. Less wear on the soldered on flash
>> 3. The A10 can expose UART and JTAG via the sd interface
>> http://linux-sunxi.org/MicroSD_Breakout
>>
>> Ehm why aren't you trying UART/JTAG over the SD-Card interface now anyway?
>
>  because they wired the wrong fucking SD card interface *without*
> notifying me.  did i say "don't ask"? :)

Sorry I did ;-). I assumed solder pads for JTAG/UART on the board.

>
>  it's actually for very very good reasons, namely that the board's
> been designed extremely well - 2 GND planes, 1 Power meaning it stands
> a high chance of passing FCC - but it's leaving only 3 signal planes.
>
>  so, only 3 signal planes for 4 DDR3 RAM ICs, processor, PMICs, NAND
> Flash, MicroHDMI, MicroUSB, MicroSD and a 68-pin connector in a space
> only 45 x 75 mm it's a goddamn miracle the engineer pulled that off -
> he's extremely competent in that regard.

Applause. Good job indeed.

>
>  so they couldn't route SD0 to the MicroSD because it was on the other
> side of the CPU, likewise SD3 would have crossed over.  so the
> engineer made a very sensible decision to swap them over... but didn't
> _tell_ me.
>
>  and i'd already truncated the GPIO pins from 16 to 8, which cut SD3
> in half.... actually now SD0.  if they'd asked i would have said "oi!"
> and asked them to drop IR_TX and IR_RX and put the full SD0 on them
> instead.
>
>  but yes.  we want a top-loading micro-sd... in the future, not not,

Someting like this you mean?
http://static.videomaker.com/sites/videomaker.com/files/styles/vm_image_token_lightbox/public/articles/15633/micro-sd-card-in-cell-phone.jpg?itok=jd9JlrmU

That whould indeed make more sense for an SD card with the OS. Which
you don't want to accidentally eject while running.

> because it's too much cost and time right now.  i shouldn't say
> "never": if on the other hand someone reading this can come up with
> around $15k we'll do it immediately.
>
>  oh, btw we're more than certainly going to the A20 now.
>
> l.
>
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