On Sat, Jun 25, 2005 at 03:21:01PM +0000, [EMAIL PROTECTED] wrote
> I will be attempting to build the system from Stage 1 tarball,
> however I'm still confused what my /etc/make.conf has to look
> like. Would anyone give a sample make.conf or point me to a good
> samples for Pentium 3 (Coppermine) ?
Please boot the machine in any version of linux (liveCD or whatever)
and execute "cat /proc/cpuinfo" and post the output here. Thats the
final authority on what CFLAGS to use. Here's what I suggest, assuming
that my PIII Katmai is basically identical to your system, and should be
applicable to Coppermine as well.
CFLAGS="-O2 -march=pentium3 -fomit-frame-pointer -pipe -mmmx -msse -mfpmath=sse"
CHOST="i686-pc-linux-gnu"
CXXFLAGS="${CFLAGS}"
MAKEOPTS="-j1"
USE="-bidi -ipv6 mmx -nls -pam sse"
There's a Canadian saying that if you give a man a fish, you feed him
for a day. If you teach him to fish, you feed him for an entire year, as
he collects unemployment insurance for several months after a few weeks
of fishing<g>. Anyhow here's a set of instructions that should probably
go into a HOWTO or FAQ somewhere. What makes Gentoo better is that you
can tweak it to take advantage of every little bit of your CPU's
capability. This means that it requires different settings for
significantly different cpus, and results in a steeper learning curve,
and it does give you opportunity to shoot yourself in the foot. Here's
the drill...
1) Boot the machine into any linux (live CD or whatever) and execute
cat /proc/cpuinfo > info.txt
and save info.txt to a floppy or print it out, but have it ready as a
reference. You will need it.
2) Generic compiler optimizations, i.e. those *NOT* beginning with "-m"
For CFLAGS I suggest... -O2 -fomit-frame-pointer -pipe
*PLEASE* use -O2. Otherwise, *YOU WILL NOT GET SUPPORT ON THIS LIST OR
THE BUGZILLA FORUM AND YOU WILL GET FLAMED BY GENTOO USERS WHO RESENT
BEING SMEARED WITH THE "GENTOO RICER" BRUSH*. -O3 is risky, flakey and
known to cause intermittent problems which can be damn hard to repeat.
-O4 or higher is like a ricer sticking a logo from a top-of-the-line car
onto a base model of the same car, and hoping to fool people. This
applies to gcc 3.x, which is the current series. *DO NOT USE EXTRA
GENERIC COMPILER OPTIONS* like -funroll-loops. The results are similar
to -O3.
For MAKEOPTS, I suggest -jn, where "n" = the number of cpu cores on your
machine. A dual-cpu system would have n = 2. A single cpu that is
"dual-core" is 2. Hyperthreading probably should not count, as it is
way overrated. The Gentoo manual recommends n+1, but I have run into
problems on an older PII machine using -j2, which were cured by
switching to -j1. A lower MAKEOPTS setting might slow down your emerge
(compile) sessions. *IT DOES NOT SLOW DOWN THE COMPILED PROGRAM*. It's
not worth the risk in order to save a bit of time at the compile stage.
3) For CHOST, refer to the info.txt file you created in step 1. Any
current Intel/AMD product works with i686-pc-linux-gnu. AMD K6 or
earlier, and "original" Intel Pentiums (60 to 75 mhz) should use 586.
4) CPU-specific compiler optimizations, i.e. those beginning with "-m"
First, go to the webpage for your compiler, and check the submodel
options for your CPU. For gcc 3.4.4 it's...
http://gcc.gnu.org/onlinedocs/gcc-3.4.4/gcc/Submodel-Options.html#Submodel-Options
For gcc 4.0.0, it's...
http://gcc.gnu.org/onlinedocs/gcc-4.0.0/gcc/Submodel-Options.html#Submodel-Options
Refer to the output from /proc/cpuinfo in step 1). It tells you what
CPU you have, so you know which model to compare against. Compare the
contents of the "FLAGS" line in /proc/cpuinfo against the list on the
webpage. Any flags that match can be used. In the case of the PIII,
the flags are mmx and sse. Add -mmmx and -msse to your CFLAGS line. If
you have any version of sse (including sse2 or higher) "-mfpmath=sse" is
also helpful. Do *NOT* use "-mfpmath=sse,387", as it is experimental,
i.e. flakey.
5) I recommend -bidi and -nls if you don't want to build umpteen
locales. If you don't run ipv6, definitely select -ipv6. Someone, in
their infinite wisdom, decided to make ipv6 the default. If you don't
run IPV6, an app built with IPV6 support will first query via IPV6, wait
30 seconds for the request to time out, and then query via IPV4.
Painfull to say the least. I recommend -pam because I recommend against
PAM. PAM makes sense if you're running a server which is accessed by
multiple users. For a home desktop, or even a corporate desktop, it is
overkill. I believe that PAM belongs in the "alternate security models"
section of menuconfig, along with NSA SELinux, etal.
6) CPU-specific flags for the USE variable
Go to webpage http://www.gentoo.org/dyn/use-index.xml and compare the
list against the "FLAGS" line of your /proc/cpuinfo output. In the case
of a PIII, the "mmx" and "sse" flags are available.
--
Walter Dnes <[EMAIL PROTECTED]>
My musings on technology and security at http://tech_sec.blog.ca
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