From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <39BD1B9B.1729B5B@mvista.com> Date: Mon, 11 Sep 2000 10:51:23 -0700 From: Mark Hatle MIME-Version: 1.0 To: clark@esteem.com, Navin Boppuri , linuxppc-embedded@lists.linuxppc.org Subject: Re: Differences between MPC823 powerpc & any other powerpc References: <1.5.4.32.20000911170434.006a51e8@pop.esteem.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: clark@esteem.com wrote: > > At 11:48 AM 5/12/00 +0100, you wrote: > > > >Hello, > > > >I would like to know what are the basic difference between the MPC823 > >PowerPC and any other PowerPC , say, the G4? Why dont the binaries running > >on G4 not work correctly on the MPC823? > > For starters the MPC823 has no FPU. I think you could compile FPU > emulation into the kernel to remedy this but I'm not sure. G4 compiled > programs may use alti-vec instructions but I'm not sure on this either. > In addition to no FPU, the 8xx series also has half of the cachelines that all of the other PPC's have. (4xx, 6xx, 7xx, 74xx, 82xx) This causes a problem with glibc [and possibly other things] which expect a certain line size to do fast memset's, memcpy's etc. (The result of having the wrong cacheline size is to miss area's of memory in the previous listed functions.) Also w/ the no FPU comes ABI issues including (especially?) var args issues. --Mark ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/