I don't have 8241/8245 experience, but I do have 8260 experience (also uses the 603e core). Floating point (FPU) works well under linux.
Using floating point in the kernel is severely frowned on, however, because it takes time, both for the calculations and for additional FPU register store/restore operations (big speed hit). IIRC, you need to specially configure the kernel or modify the kernel because the kernel assumes it does NOT execute floating point instructions internally and therefore doesn't save/restore the FPU registers for its internal use (i.e. the kernel context does not have FPU registers saved/restored, user contexts do have FPU registers saved/restored). You don't want to go there unless you really, really have to and if you think about the problem a bit, I suspect you will discover you don't have to. Pretty much any fairly recent gcc compiler should work. For a very good head start in configuring your environment, see Wolfgang Denk's Embedded Linux Development Kit (ELDK). http://www.denx.de/e/index1.php?main=doc/ELDK/index gvb At 09:38 AM 3/4/2003 -0500, ivancheng at avantwave.com wrote: >Hi, > > We are evaluating the mpc8241/8245 on the floating point unit. For they >are based on the 603e core, there is a hardware floating point support. And >we are going to cross-compile the kernel and apps in intel platform. I am >very interested to know > >- whether the FPU is supported in the linux distribution in both user/kernel >mode. >- If so, how should I compile for the applicaiton/driver with gcc? >- , and in which version of gcc does it support? > >Thanks very much for any comments. > >Ivan Cheng > > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
