Re: How can I jump to non-linux address space?

[Russell King <rmk@arm.linux.org.uk>]

On Fri, Oct 05, 2001 at 05:38:53PM -0700, Ian Thompson wrote:
> I tried both of these, and I must be doing something wrong.  For (1), I
> grabbed the code you mentioned from the RiscPC port (setup_mm_for_reboot()
> and some code from the soft reset routine).  After calling
> setup_mm_for_reboot, if I call __ioremap(), the processor hangs.  If I shut
> down the MMU, I get the same results.

You will need to disable interrupts if the machine vectors are located at
address 0 (check your boot logs with a recent kernel for a message like
"Vectors relocated to ...").

It's probably best to call cpu_proc_fin(), setup_mm_for_reboot() and
cpu_reset(address) directly rather than making your own copy - these
functions already do the right things for you.  setup_mm_for_reboot()
will remap all of user space with a 1:1 virtual to physical mapping,
and hopefully on the Xscale, the two cpu_* functions do the intended
setup for this (I've not reviewed the xscale stuff in any great detail
yet though).

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html