[Automated-testing] minnowboard boot & control

[William Mills]

On 02/04/2014 04:51 PM, Otavio Salvador wrote:
> Hello,
>
> On Tue, Feb 4, 2014 at 7:45 PM, William Mills <wmills at ti.com> wrote:
> ...
>> On BeagleBone Black:
>> The Si Boot ROM can boot from TFTP.
>> The Si Boot ROM can boot from eMMC or SD.
>> With relay controlled pull-ups/downs I can control the boot device.
>>
>> With this control I can recover a device regardless of what a previous test
>> has done to eMMC or SD Card.
>> (My work is documented at:
>> http://processors.wiki.ti.com/index.php/BeagleBone_in_a_Board_Farm
>> )
>
> Except U-Boot tests or am I wrong?
>

I think your asking if I can test experimental (broken) u-boots and
still recover.

Yes, with this setup I can.
With the relays, I set the boot mode to TFTP at the ROM level.
The full boot sequence is:
ROM -> TFTP SPL -> TFTP Uboot -> whatever U-boot decides

With an unpatched u-boot you can use the serial console to interrupt
and get control of u-boot and then have it boot whatever you want.

(Back in July I had u-boot hacks to make it get uEnv.txt from TFTP also 
and then the files on the TFTP were in complete control.
Resurrecting that work and cleaning it up is on my TODO list :)