Gentoo Archives: gentoo-user

From: "Hemmann
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Changing CFLAGS
Date: Sat, 28 Apr 2007 05:13:05
Message-Id: 200704280707.04269.volker.armin.hemmann@tu-clausthal.de
In Reply to: [gentoo-user] Changing CFLAGS by Alex Schuster
1 On Samstag, 28. April 2007, Alex Schuster wrote:
2
3 >
4 > What would be the best way to do this?
5
6 complete reinstallation.
7
8 > I thought about unpacking
9 > a stage1 tarball, changing CFLAGS, calling bootstrap.sh and doing
10 > an emerge -e world, but this would overwrite things in /etc and
11 > clutter my file system with more things I do not really want,
12 > like creating entries in /dev. I would rather like to keep the
13 > current setup as it is.
14
15 use knoppix.
16 If you don't want to reinstall everything and the XP is just a temporary
17 replacement, get a knoppix livecd. It lets you save things to a file, if you
18 want to.
19 >
20 > I think that I saw a howto once about what to do in such a case,
21 > but at that time I did not need it, and now I cannot find it.
22
23 the howto is: remove the system and start from scratch.
24
25 >
26 >
27 > BTW: What exactly are the benefits from using march instead of
28 > mcpu? Is there a noticeable difference in speed anyway? With mcpu
29 > I would not have the trouble I am having now...
30
31 Your trouble started, when you switched to a completly different cpu...
32
33 mcpu = only rearranging stuff so it might run better on the cpu specified. No
34 instructions and features used, that are not available on all the other cpus
35 from a family (in theory, a binary built with mcpu=athlon-xp should be able
36 to run on a i486).
37
38 march = optimizing for the specified cpu. Using all features and instructions
39 available, building stuff not able to run on other cpus. (so a resulting
40 binary of march=athlon-xp won't run on a i486)
41
42 usually march is faster on the given cpu, mcpu is more compatible.
43
44 --
45 gentoo-user@g.o mailing list

Replies

Subject Author
[gentoo-user] Re: Changing CFLAGS Alexander Skwar <listen@×××××××××××××××.name>
Re: [gentoo-user] Changing CFLAGS "Csányi András" <sayusi.ando@×××××.com>