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From: "Ian Thompson" <ithompso@stargateip.com>
To: "Russell King" <rmk@arm.linux.org.uk>
Cc: <linux-kernel@vger.kernel.org>
Subject: RE: How can I jump to non-linux address space?
Date: Fri, 5 Oct 2001 17:38:53 -0700
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> Essentially, you have 2 choices:
>
> 1. Turn off the MMU.
> 2. insert a 1:1 physical to virtual mapping for the ROM and call the code.
>    (with interrupts disabled).
>
> Which one works depends on what the ROM code requires.
>
> There is an example of (1) in the current ARM kernel sources - the RiscPC
> port uses this method to reboot - we can't activate the hardware reset
line
> on these machines, so our only option is to use this method.

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.

Where would be a good place to find an example of how to implement your
second suggestion?

thanks.  sorry to keep bothering you.  i'll also try asking on the arm
newsgroup...
-ian

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