From mint-bounce@lists.fishpool.fi Mon Aug 15 20:52:25 2005 X-Original-To: fnaumann@mail.boerde.de Delivered-To: fnaumann@mail.boerde.de Message-ID: <4300E409.3080101@klockars.net> Date: Mon, 15 Aug 2005 20:50:49 +0200 From: Johan Klockars User-Agent: Mail/News Client 1.0+ (X11/20050503) MIME-Version: 1.0 To: Mint list Subject: Re: [MiNT] what's wrong with this code? References: <20050810084953.GA29857@hysteria.sk> <1123778764.5688.9.camel@linuxbox> <20050815064515.GA21766@hysteria.sk> <4300696F.9000301@klockars.net> <1124121226.5688.19.camel@linuxbox> In-Reply-To: <1124121226.5688.19.camel@linuxbox> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-ecartis-version: Ecartis v1.0.0 Sender: mint-bounce@lists.fishpool.fi Errors-To: mint-bounce@lists.fishpool.fi X-original-sender: johan@klockars.net Precedence: bulk List-help: List-unsubscribe: List-Id: X-List-ID: X-Virus-Scanned: by amavisd-new at relay.boerde.de X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on relay.boerde.de X-Spam-Status: No, hits=-1.0 tagged_above=-50.5 required=7.0 tests=AWL, BAYES_00 X-Spam-Level: >>But has he, really? I have nothing against being proved wrong, but... >> >>Odd's wrong (or very unclear) on one point, which is that the user stack >>would somehow be 'lost'. >> >> > > Thats because the RTE should pull USER stack from the stackframe, but >since the SV bit is forced in the stored SR, you now use this as a SUPER >stack. I.e. the USER stack is lost. > > Uhm... In what universe does a 680x0 RTE pull any stack pointer what-so-ever from the stack? On the stack you'll only find (for a Trap on a 680x0, x > 0): 0(a7).w - SR 2(a7).l - return address 6(a7).w - vector offset (not there on the 68000) No stack pointer is ever saved before entering an exception handler, nor restored on RTE. There are physically separate registers for the various stack pointers, which just get "remapped" in hardware depending on the bits in SR. -- | Why are these | johan@klockars.net | .signatures | | so hard to do | http://www.klockars.net | well? | (fVDI, MGIFv5, QLem)