Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!udel!mmdf From: Tyler Sarna Newsgroups: comp.os.minix Subject: Re: Better performance for 68K based minix? Message-ID: <51516@nigel.ee.udel.edu> Date: 22 Apr 91 16:23:22 GMT Sender: mmdf@ee.udel.edu Lines: 32 In comp.os.minix, Christoph van Wuellen writes: > It is totally illegal that FS calls phys-copy. > This works (INCIDENTALLY) on the Mac, ST, and AMIGA since they have > no MMU and memory protection hardware. This isn't strictly true. Many Amiga's and Mac's have MMU's, and apparently the new Atari machine (being 030-based) does too. It isn't that they don't have them, they just aren't currently used under Minix. Someone may well use the MMU some day, either for complete VM, just for memory protection, instead of shadowing, or to simply remap memory above 0x00FFFFFF so that Minix can use it (sizeof(foo *) == 4 means a pointer is 4 bytes, darnit. If only three were needed, sizeof would be three. Why do otherwise highly intelligent people insist on storing extra garbage in pointers?!?! There are these neat little things called "structures" or "records", which were designed just for things like this.) > FS really is NOT allowed to access anything outside its address space > since it is a normal process. It has to call a kernel function to > copy stuff to another process, which might e.g. reside on another > machine! Or more likely, "which might be at a virtual != physical address". -- Tyler "Ty" Sarna tsarna@polar.bowdoin.edu "My hair does not require trimming, you lunkhead." - Data