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From: Hollis Blanchard <hollis@penguinppc.org>
Date: Sun, 30 Oct 2005 20:28:49 -0600
To: "Ingmar" <i2a@gmx.net>
Cc: linuxppc-dev list <linuxppc-dev@ozlabs.org>
Subject: Re: exception vectors
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On Oct 30, 2005, at 6:35 PM, Ingmar wrote:
>
> I am trying to overwrite the exception vector space of an ibook G4 :).

Why?

> I have set up (for every exception) a small piece of code, that's a=20
> prefix of a
> handler to be called. My problem is, that writing the =93small=94 =
chunks=20
> of code to
> the exception vector space gives no problem(so it seams) but writing=20=

> all the
> pieces of code as one chunk gives a exception [dsi, dsisr 0x42000000],=20=

> this
> indicates a store problem.

Code please. You're just calling memcpy?

> I have tried different modes of copying, mmu on/off, also chanced the=20=

> WING bit,
> switched the exception prefix on.

You could not have gotten a DSI if you disabled the MMU...

> I don't believe putting the exception vectors to there =93place=94 one =
by=20
> one is the
> right way, in the Linux kernel the kernel get relocated and the code=20=

> comes into
> place. I have taken this as an example, unfortunately to to result =
:(..

So you are not trying to overwrite Linux's functioning exception=20
handlers, but rather trying to write your own OS?

>  - Am I overlooking something?
>  - Is the a =93standard way=94 to overwrite the exception vector space =
of=20
> a powerpc?

Do you think this is a common task? :)

-Hollis