[Arm-netbook] Hacking the Mele A1000 - ultra beginner guide

[Julien Forgeat]

Hi All,

I am making slow progress but now running in problems with building the 
kernel. Turns out arm-linux-gnueabi-objdump segfaults with the following:

/bin/sh: line 1:  6174 Segmentation fault      arm-linux-gnueabi-objdump 
-D standby.elf > standby.lst

Complete log: http://pastebin.com/Cc9jdxd8

After following instructions from 
http://rhombus-tech.net/allwinner_a10/kernel_compile/ (I have 
gcc-4.4-arm-linux-gnueabi from the Ubuntu repo)

As a side question, is this kernel in any way specific to the Mele or is 
it the same for all A10s? In the later case, would it make sense to have 
a PPA or a Deb repo with a built kernel available, or even a .deb we can 
download?

Cheers,

Julien

On 03/23/2012 04:22 PM, Henrik Nordström wrote:
> fre 2012-03-23 klockan 10:34 +0800 skrev julien at forgeat.name:
>> Received the USB TTL Serial/UART module :-)
> Great!
>
>> As Alejandro stated, the 2.54mm cable connectors do not fit, we can at
>> most fir two out of 4, maybe 3 but that would be risking breaking
>> something ^^
> Yes..
>
> you can strip the middle cable connector from it's plastic to cut down
> size a bit, which may allow you to fit GND, Rx, Tx
>
> Also pay attention to order of Rx and Tx. These needs to be crossed. Rx
> on your cable to Tx on mele, Tx on cable to Rx on mele.
>
>> But then, I have been thinking:
>>    (1) the 3.3V Vcc is apparently not always needed (is it only if the
>> cables are very long?)
> If you have a fixed voltage (including voltage selected by jumper)
> serial cable then Vcc is not needed.
>
> The 3.3V pin in the serial port is for serial cables with variable
> voltage level. So you should leave this unconnected in most cases.
>
> The only case when you should connect the serial port 3.3V to the serial
> cable is if you use a buffered/isolated cable with variable voltage
> level and requires a VREF/VIO reference power driving the I/O logics at
> the right level for the board.
>
> Almos all cables have fixed I/O voltage level (single, or selected by
> jumper), and on these you should leave the VCC unconnected. If the cable
> do have a VCC pin then you MUST NOT connect VCC. The VCC pin provided in
> the cable is for powering the device you connect to.
>
>>    (2) 2 cables fit in the connector
>>    (3) We should be able to get ground from somewhere else on the board
> Yes.
>
>> So is it dangerous the connect Rx and Tx on the UART port, Ground on
>> the USB port and not to connect Vcc (or why not, get Vcc from the USB
>> port)?
> ground should work.
>
> But DO NOT connect VCC from there. You will likely destroy something.
> * Your cable do not have a VREF/VIO connection
> * VCC of your cable is 3.3V. USB uses 5V.
>
> Connecting VCC of your cable to USB you short the 3.3V serial cable
> power output to a 5V power usb power output, and BAD things are likely
> to result, possibly (but probably not) involving magic blue smoke
> leaving the A10 CPU or usb serial chip if not 5V tolerant.
>
> Regards
> Henrik
>
>
> _______________________________________________
> arm-netbook mailing list arm-netbook at lists.phcomp.co.uk
> http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
> Send large attachments to arm-netbook at files.phcomp.co.uk

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.phcomp.co.uk/pipermail/arm-netbook/attachments/20120329/e97dbc08/attachment.html