Say Y here if your target has the gdb-sh-stub
package from www.m17n.org (or any conforming standard LinuxSH BIOS)
in FLASH or EPROM.  The kernel will use standard BIOS calls during
boot for various housekeeping tasks (including calls to read and
write characters to a system console, get a MAC address from an
on-board Ethernet interface, and shut down the hardware).  Note this
does not work with machines with an existing operating system in
mask ROM and no flash (WindowsCE machines fall in this category).
If unsure, say N.

This option will cause messages to be printed if free stack space
drops below a certain limit. Saying Y here will add overhead to
every function call and will therefore incur a major
performance hit. Most users should say N.

If you say Y here the kernel will use a 4Kb stacksize for the
kernel stack attached to each process/thread. This facilitates
running more threads on a system and also reduces the pressure
on the VM subsystem for higher order allocations. This option
will also use IRQ stacks to compensate for the reduced stackspace.

If you say Y here the kernel will use separate kernel stacks
for handling hard and soft interrupts.  This can help avoid
overflowing the process kernel stacks.

This prints out a code trace of the instructions leading up to
the faulting instruction as a debugging aid. As this does grow
the kernel in size a bit, most users will want to say N here.

Those looking for more verbose debugging output should say Y.

Enabling this option will make stacktraces more accurate, at
the cost of an increase in overall kernel size.

If running in painfully slow environments, such as an RTL
simulation or from remote memory via SHdebug, where the memory
can already be guaranteed to ber zeroed on boot, say Y.

For all other cases, say N. If this option seems perplexing, or
you aren't sure, say N.