What do you use for kernel debugging?

[O'Connor, Daniel]

On 1 Oct 2014, at 0:14, Julian Elischer <julian at freebsd.org> wrote:
> Unfortunately you can't use a USB serial as it requires the USB stack 
> be  working before it can be used..
> similar with ethernet connected debugging which requires that the 
> driver for the ethernet hardware support it.
> (which why we don't have it in the tree though it has been done 
> several times in the past).

There IS a USB debug standard, Linux has some code to support it.

I am not sure what percentage of hardware has it hooked up though (the host controller has a designated debug port but it could physically be anything).

http://www.coreboot.org/EHCI_Debug_Port

The hardware is bit more expensive than a null modem or firewire cable though :(

Regards,
	Daniel O’Connor

Senior Software Engineer
Isilon Platforms Team