Change to glibc build instructions -- RFC

Jim Gifford lfs at
Tue Jul 27 08:10:15 PDT 2004

Alexander E. Patrakov wrote:

> Kevin P. Fleming wrote:
>> Thomas Beneke wrote:
>>> You compile glibc with (kernel-)features you will never have in 
>>> binaries compiled on older kernel versions.
>>> (sysdeps/unix/sysv/linux/kernel-features.h)
>> That is correct, so those binaries compiled on older kernel versions 
>> won't attempt to use any of those features, because they are not 
>> aware of them.
>> The only negative I can see to building glibc with 
>> --enable-kernel=2.6.0 is that if you compile and link a _static_ 
>> linked application against this glibc and then copy that binary to a 
>> system running a kernel older than 2.6.0 the binary won't run 
>> properly (if at all).
> This binary won't run even without --enable-kernel=2.6.0 because glibc 
> uses TLS in its initialization, and 2.4 kernels don't provide TLS. So 
> in fact we lose nothing from --enable-kernel=2.6.0
I have been using --enable-kernel= in some form for a while with no 
issues, in fact most distro's when they build there glibc are also using 
this. Gentoo, Debian, and Fedora do this exact same command line. PLD, 
Rock, and knoppix us --enable-kernel=current. The reason for using 
2.6.0, is because it's a generic reference to the kernel,.

Ryan has also suggested using --enable-kernel to be whatever UTS_RELEASE 
is in linux-libc-headers linux/version.h.

So in our case with would be --enable-kernel=2.6.7

jim at
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