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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msunews!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!swrinde!ihnp4.ucsd.edu!dog.ee.lbl.gov!news.cs.utah.edu!cc.usu.edu!kurto From: kurto@cc.usu.edu (Kurt Olsen) Newsgroups: comp.os.386bsd.questions Subject: Re: Nagging FreeBSD 2.0 questions Message-ID: <1995Feb16.225325.41987@cc.usu.edu> Date: 16 Feb 95 22:53:25 MDT References: <1995Feb16.025123.8370@wdl.loral.com> Organization: Utah State University Lines: 49 On Feb 16, rpt@miles (Richard Toren) wrote: > 2) CPU identification. > My system was ordered with a Cyrix 486DX/66 processor. The CPU id line > that appears during boot says: > " kernel: CPU: Cy486DLC (486-class CPU) Origin = "Cyrix" " > I thought that the DLC was lacking a fpu and not the same as a DX. > I found the test in /usr/src/sys/i386/i386/locore.s. > 1) would a mis-identification cause any problems such as the use of a > fpu emulator rather than the on-board one? > 2) is this the only test to id a Cyrix processor? > > You are probably thinking, "RTFC (read the flippin chip) dummy. > This chip does not say Cyrix anywhere on it (it also does not say > Intel, or 'ti'). What it does say is "it's ST" with the ST inversed > in a white box. I had this same problem with a DX2/50 (according to Cyrix all their DX2s leave the factor with a large green heat sink and DX2 printed on it.) If you are willing to rip your chip out there should be a lot number on the bottom (mine was FLxxxxx.) However 2.0R identified my chip as a DLC as well. I sent a note to the hackers list, and Bruce Evans (or Rod Grimes, can't remember which) replied that the DLC has some problems with cache and DMA. To fix the cache/dma problem FreeBSD disables the cache on the I/O channel. I think they misunderstood my problem, which was the chip identification. Anyway I hacked out the code to identify the DLC with a 'jmp 2f' just before the section that checks for a DLC. This had the net effect of increasing my system performance by about 250%. I spent a couple of hours talking/holding with cyrix and they told me that their methods of indentifying chips were proprietary and that if I sent them the source they could try and generate a patch, but they also wanted some method of running/testing any changes that they made. I don't think that the person I was talking with really understood what I was talking about when I said "Unix." 'Bout the only thing I could think of to do here would be to send them a CD and wait and see, never did get around to it since I came up with the 'patch' above. > Is it really Cyrix?? Does it have a fpu?? Don't know, but I would suspect so. > Rip Toren > rpt@miles.sso.loral.com -- Kurt Olsen (kurto@cc.usu.edu) <a href="http://www.usu.edu/~kurto/">Me & my Atari Lynx</a> archive.