From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A7DC4E7.38588294@mvista.com> Date: Sun, 04 Feb 2001 16:08:55 -0500 From: Dan Malek MIME-Version: 1.0 To: Tom Gall CC: Troy Benjegerdes , linuxppc-dev@lists.linuxppc.org Subject: Re: Power3/4 Was: Re: Fast Altivec References: <3A7AE117.628B22A6@mvista.com> <20010202125143.D31120@altus.drgw.net> <3A7D8C19.B829A8D0@mvista.com> <3A7DB6B5.7370D32D@vnet.ibm.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Tom Gall wrote: > .... At the moment it is nice > that one define handles issues for the entire family of boxes. I learned years ago when I did a processor port it was important to separate the processor and platform specific configuration definitions. When you do that second platform that uses the same processor you will discover how badly it was integrated :-). > .... But you are right > it could be split and I can see the case for making the split. It seems like these are CHRP machines with some kind of extended address bus mapping? We either need to devise a new configuration name or integrate the changes with some "CHRP extension" that isn't based on the POWERx configuration. > Which set of changes are you interested in using for the 7450? You say the chip > has 36 bit addressing, how does that work? It can use a 36-bit physical address bus, so any processor register that holds a physical address (SDR, page tables, etc) has "extended" bits that can be used when the proper configuration bits are set in the HID0. I was going to use some of the I/O mapping functions (often with comments like "big hack" in them :-), to support this as well. Generally, I am looking at some VM changes that allow us to support beyond 4G virtual/physical with 32-bit processors (other than using the HIGHMEM hack). Some of the things in BRIDGE64 and POWERx are appropriate to use but seem to have knowledge of the underlying platform, so a slightly different configuration name and minor code changes would be useful. I just started looking and still have lots of work to do here. > 6392 messages yet to read... ug! Boy am I behind in mail since LinuxWorld... Heh... -- Dan ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/