On Mon, 14 Jun 2010, Mitch Bradley wrote:

First, the primary use case for "keeping OFW alive" is for debugging purposes.
OFW remains resident in memory so that, if the OS is set to allow it (not the
default), a hot-key freezes the OS and enters OFW, where a human can inspect
the state of devices and OS data structures. A high skill level is required,
so it's okay if some fiddling is necessary to find or establish virtual
addresses or do similar magic .  

Why would you impose such pain on yourself in order to try to make OFW a 
viable debugging tool on ARM for live kernels, while you can achieve the 
same and more much less intrusively and so much more safely with a JTAG 
based debugger?

If the cost of a JTAG solution is a concern, you can order USB based 
JTAG dongles on the net for less than $30 and use them with OpenOCD[1].

Otherwise, what's wrong with already supported kgdb, or even kdb?

[1] http://openocd.berlios.de/web/


Nicolas