I've got several designs with multiple AVR, as well as USB "intelligent" devices.
So one of the issues, is have a "serial" port is not a "option" in some of the designs.
I see the ideal would be to add a "console" driver to uboot that simulates a serial port.
And possible a driver also for the "kernel". (a gadget driver gives me a psedo network device, so I guess I could just telnet, but that does leave me hanging for kernel debug.
Any ideas or suggestions?
There's a usbtty driver in u-boot. With a low-level driver for the ap7000 udc, this might be something similar to what you want perhaps?
For the kernel, you have the CDC ACM (serial) and Ethernet gadget drivers. I think it will be difficult to use those as an early debug console, as they depend on so much infrastructure (interrupts, DMA, etc.) that they have to be initialized late. But that shouldn't really be a problem unless you're debugging the early kernel init code, and I think netconsoles are usually initialized late anyway.
cool.
Thanks. usbtty will save some time.
Is there any example code for using the udc in a stand-alone application?
