[coreboot] Re: Debugging EHCI - but Pre-CBMEM romstage/ramstage console overflowed, log truncated

[Kyösti Mälkki]

On Sun, Oct 27, 2019 at 8:53 AM Mike Banon  wrote:
> Good day, I'm researching if it's possible to support a cheaper
> FT232BL-based EHCI usbdebug dongle like the already-supported FT232H
> -- to make EHCI debugging more accessible to the newcoming
> coreboot'ers -- and need the detailed logs (i.e.
> CONFIG_DEBUG_CONSOLE_INIT) to figure this out.

EHCI debug mode requires USB 2.0 High Speed (480 Mbps) device which
FT232BL is not. That hardware can possibly provide console with GRUB
payload but nothing earlier than that.

Kyösti