DIY EHCI debug dongle
The wiki is being retired!
Documentation is now handled by the same processes we use for code: Add something to the Documentation/ directory in the coreboot repo, and it will be rendered to https://doc.coreboot.org/. Contributions welcome!
Hardware
An EHCI debug dongle can be built using two Cypress FX2LP prototyping boards with CY7C68013A. There are a few boards in the 10-15 EUR pricerange to choose from and a dozen suppliers in ebay.
A slower uni-directional boot console has been demonstrated to work with one such board and a TTL-UART-to-USB adapter.
Schematics
Schematic is modified from Cypress Application Note AN63787 [1].
Dongle firmware
Firmware is built with sdcc using fx2lib.
Original git repository [2]. Offline.
Recent updates are here [3].