[coreboot] $7 cheap FT232H board as EHCI debug dongle for coreboot - would it work?

[Mike Banon]

> Not likely those PCBs have gone through much testing on assembly line, how about 4...

>From about 100-200 reviews for these cheap " aliexpress boards " so
far I've found just one negative that's quality related and not
shipping related ( FTDI chip was badly soldered ) - quite a low
failure rate. These boards are very simple and their failure rate
mostly depends on the failure rate of FTDI chips and their soldering
quality

> It writes just the same you get with cbmem -c utility, assuming you
can reach OS on the DUT.

Didn't know that, but its' too late ;)

Best regards,
Mike Banon

On Mon, Mar 5, 2018 at 1:36 PM, Kyösti Mälkki <kyosti.malkki at gmail.com> wrote:
> On Mon, Mar 5, 2018 at 12:18 PM, Mike Banon <mikebdp2 at gmail.com> wrote:
>> Hi Kyosti, Thank you very much for your reply!
>>
>> I will try to get a couple of these FT232H boards: perhaps just 1 is
>> required for the successful setup, but these boards are not common
>> (just 15 or 20 search results) so maybe its' a good idea to take 2 ;)
>>
>
> Not likely those PCBs have gone through much testing on assembly line,
> how about 4...
>
>> If this FT232H board works, it would be an ideal replacement both for
>> commercial AMIDebug Rx / Ajays NET20DC (because much cheaper) and
>> FX2LP (because no DIY will be required). Maybe this info could even be
>> added to the official coreboot wiki, but I don't have an account there
>> and it seems hard to get, so I'm using the DangerousPrototypes wiki
>>
>
> It won't become a compatible replacement, as you would need to modify
> the (proprietary) software of both device-under-test and the host.
> FT232H could be made to work with linux kernel early_printk=dbgp but I
> don't think anyone has done that.
>
> FX2LP approach was able to mimic the net20dc USB descriptors,
> including the special response of debug feature and endpoint number
> assignment.
>
>> Will write an update when I'd get the boards and test them with AMD
>> G505S laptop. I'm curious what Lenovo G505S is writing to the coreboot
>> log while it boots
>
> It writes just the same you get with cbmem -c utility, assuming you
> can reach OS on the DUT.
>
> Kyösti