While I know that, technically, the only i586 machines are the Pentium and Pentium MMX, it is still nice that I can use some headless AMD K6/2 machines I have lying around for CentOS 4. Many thanks for the effort expended to get that working.
On Sat, 2005-07-30 at 17:55 -0400, Lamar Owen wrote:
While I know that, technically, the only i586 machines are the Pentium and Pentium MMX, it is still nice that I can use some headless AMD K6/2 machines I have lying around for CentOS 4. Many thanks for the effort expended to get that working.
The AMD K6-2+ don't run the i686 version?
I was fairly certain the Nx686 core (K6) was a 3-issue, superscalar i686 ISA compatible ALU + non-pipelined AMD x87 FPU slapped on?
In fact, I thought the primary difference between the Nx586 core and the Nx686 core was the move from i386/486 ISA (i386 in early Nx586, i486 in the latter K5s as it's TLB was made fully i486 ISA compatible) to i686 (all K6 units)?
They should run i686 ISA code the last time I checked.
On Saturday 30 July 2005 18:25, Bryan J. Smith wrote:
The AMD K6-2+ don't run the i686 version?
Don't think cmov is supported, but I could be wrong. I know the installer installs the i586 kernel, and I know that the nahant beta would not install. Following is /proc/cpuinfo for the box in question. Note that it is not a K6/2+ (which has L2 cache on die, like the K6/3, just less cache, along with other highly desirable features), but a straight, 300MHz K6/2.
CPU Info: [root@webcam2 ~]# cat /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 5 model : 8 model name : AMD-K6(tm) 3D processor stepping : 12 cpu MHz : 300.962 cache size : 64 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr mce cx8 pge mmx syscall 3dnow k6_mtrr bogomips : 591.87
Hmmm, doesn't list cmov in the flags. In contrast, my Pentium M laptop: [lowen@localhost ~]$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 9 model name : Intel(R) Pentium(R) M processor 1700MHz stepping : 5 cpu MHz : 599.650 cache size : 1024 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr mce cx8 mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 tm pbe est tm2 bogomips : 1185.43
Lists cmov in the flags.
I bought eight of these boxes in one lot; they are Agilent OC-12 ATMprobes stripped of their OC-12 sniffer cardset (the sniffer cards have more CPU than the motherboard; twin StrongARM's plus some FPGA logic plus an i960 on a PCI dual card and an ISA card (the ISA card used only for power, and it contains that actual OC-12 PHY's (622 S/UNI PMC chips and glue to the twin StrongARM card; each StrongARM has, I think, 256MB of RAM, where the K6 was only given 128MB). I paid $20 per box. Serial console by default; they do have a keyboard port up front hidden behind a panel, but no VGA. Four PCI's and three ISA slots, and a peculiar ATX-connectored open frame power supply. One usable IDE channel is available, on which is hung a single 4.3GB HD, and internally there is a Hitachi CV 8MB CFA drive (on the secondary channel, but set as the primary boot drive). BIOS is Phoenix, and has serial port redirection. Manufacturer string in the BIOS is 'Banner 0.12'.
So, no, i686 doesn't work.
Now, for the acid test for CentOS 4's i586 support; I have a dual Pentium 133 server on which to test, including the nasty DAC960 RAID and four Adaptec EISA SCSI adapters (for an array of CD-ROMs in a LUN-expander library; over 100 CD-ROM drives on on box). If it will boot on frankenbox, it'll boot anywhere :-). I'm not sure what I last ran on the box; might have been Red Hat 8.0 or so.
On Sat, 2005-07-30 at 20:21 -0400, Lamar Owen wrote:
Don't think cmov is supported, but I could be wrong.
That's right, the optional cmov instruction is used by default in the i686 target of GCC.
On Sat, 2005-07-30 at 17:55 -0400, Lamar Owen wrote:
While I know that, technically, the only i586 machines are the Pentium and Pentium MMX, it is still nice that I can use some headless AMD K6/2 machines I have lying around for CentOS 4. Many thanks for the effort expended to get that working.
You are very welcome, we want to continue to support the i586 processors and alpha processors ... and maybe sparc processors in the future. All which are not currently supported by the upstream provider.
Booting the i586 kernel in anaconda does sometimes cause some issues with people who need to use "dd" drivers though. So, when we put out the CentOS 4 Single Server CD (hopefully quite soon), we will have a straight i686 boot option there. That should allow for an exact copy of the "i686 only" boot process for people that need that option too.
At some point in the future (for upstream compatibility), we may make the main CD-1 / DVD "i686 boot" only and provide an "i586" Single Server CD installer. Those decisions are for another time.
We are striving to be the best OS out there, not just a copy of the one of the best OSs out there :)
-- Johnny Hughes http://www.centos.org/
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Bryan J. Smith -
Johnny Hughes -
Lamar Owen