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

[Mike Banon]

These digikey cables do not explicitly mention that they have FT232H
chip, also they cost $23.5 minimum while aliexpress board costs $7 -
3x times less expensive

On Mon, Mar 5, 2018 at 7:06 PM, Vadim Bendebury  wrote:
> Did you consider one of these:
>
> https://www.digikey.com/products/en/cable-assemblies/smart-cables/468?k=ftdi...
>
> there are many options, it is important to match the cable's VDD to your
> board's (1.8V vs 3.3V), the rest of the parameters is way less important.
>
> -vb
>
> On Sat, Mar 3, 2018 at 5:27 AM, Mike Banon  wrote:
> > Good day! I am looking for the dirt cheap EHCI debug dongle. Initially
> > I found these instructions for FX2LP -
> > https://www.coreboot.org/DIY_EHCI_debug_dongle - but they require a
> > lot of manual soldering/mods which depend on your boards revision and
> > I am not sure if the currently produced boards are 100% compatible
> > with the wiki instructions
> >
> > But then I noticed a coreboot has USBDEBUG_DONGLE_FTDI_FT232H option:
> > " Use this with FT232H usb-to-uart. Configuration is hard-coded to use
> > 8n1, no flow control "
> >
> > Kyösti Mälkki tested it " with gizmosphere/gizmo1 Explorer add-on
> > board, which exposes the following device:
> >    0x0403 Future Technology Devices International, Ltd
> >    0x6014 FT232H Single HS USB-UART/FIFO IC "
> > but gizmo1 is expensive and I am not a fan of the single board
> > computers (SBCs) : they all require the binary blobs which could
> > contain the scary backdoors
> >
> > However, there are $7 cheap FT232H boards with USB available at
> > AliExpress:
> >
> > https://www.aliexpress.com/item/NEW-CJMCU-FT232H-Multifunction-High-Speed-US...
> >
> > I plan to get a couple of these boards, connect them to each other
> > with 1P 2.54mm wires, plug the 1st board into master PC
> > (coreboot-PC-under-debug) USB 2.0 port and the 2nd board into slave PC
> > (another coreboot PC which will be logging the debug info)
> >
> > Please tell me: could this setup work in theory, or there are obvious
> > shortcomings that could prevent it from working?
> >
> > Best regards,
> > Mike Banon