On Wed, Nov 09, 2005 at 03:35:42PM +0100, Holly Bostick wrote: > Norberto Bensa schreef: > > Peter Ruskin wrote: > > > >> ebegin "Checking that /usr/src/linux is linked to booted kernel..." > >> if [ "/usr/src/linux-$(uname -r)" != "$(ls -l /usr/src/linux|cut > >> -f2 -d\>|cut -f2,3,4 -d' ')" ] > > > > > > This looks more complicated than it really should be. Just run "ln" > > on reboot (stolen from your post): > > > > rm -f /usr/src/linux ln -s /usr/src/linux-$(uname -r) /usr/src/linux > > > > Thanks for the tip-- but (no offense meant) who cares?
Norbertos suggestion and Peters refinement were useful to me as examples of one plausible interpretation of what /usr/src/linux symlink should be - a shorthand way of finding the source for the running kernel. I was glad to see that I was not the only one who was not clear on its intended use, and hence how it should be maintained. > Can someone tell me on what basis this *needs* to be done as a standard > operation? If it were done as standard, then it would make the commonly held assumption that it points to the currently running kernel correct unless an explicit action had been taken by a super user since the last reboot... But that is a justification or argument for doing so - it appears from what you say that there is no *need* for it to be so (although the same could be said about an awful lot of the Unix/Linux filesystem organization - it is arbitrary until some application or process that you use is written to depend on it).. > -- If you have some external module that compiles against the kernel > source, you most likely need it against *all* kernel sources, not just > the running one (so redirecting the link is only of limited usefulness); Ok - this seems to be the bit that I am a little unclear on. If there are, as indicated in your earlier response (which I was still mulling over) "applications, libraries and external kernel modules" that need to be compiled against a kernel, and we want to be able to use grubs ability to select from a choice of kernels, what is the mechanism by these we ensure the correct applications, libraries and external kernel modules (lets call them 'objects' to avoid having to list the possibilities each time - not to be confused with the current trendy programming paradigm) are used for the currently running kernel? If the binaries are to be stored in a kernel dependent location, like the kernel modules build within the kernel source tree that are built to /lib/modules/<kernel-version>, then /usr/src/linux cannot really be being used as a symlink (ie a way of accessing the kernel files without needing to know which version it is) because the build process will need to know the target kernel version in order to make the directory names or tag. In effect, it could equally well be a file called '/usr/src/build-kernel' which contains the version number of the kernel being compiled for...? Anyway, if I understand you correctly, if you are not building anything, then it doesn't matter. And there is certainly no justification is assuming you are building for the kernel that is currently running. Right? Presumably these kernel dependent objects only need emerge to download the source once, but then must be rebuilt once for each kernel you want to install - right? And somehow the binaries will be kept separate and the correct ones chosen at boot time based on the active kernels knowledge of its own version identity. Is this what 'sys-kernel/module-rebuild' is intended to take care or for us? So we just /usr/src/linux to the newly installed kernel and run module-rebuild and the kernel dependent modules will all be made for the new (or modified) kernel. It seems that the desirablility of having the boot process automatically update the symlink depends on how much you want to be able to use /usr/src/linux as a shorthand for manually typing "/usr/src/linux-`uname -r`", which is probably a bit arcane for a nieve user... > Not getting it at all. How many kernels does one keep in a bootable > state, anyway-- and use commonly, without needed external modules, no > less-- that this would be necessary? I typically have 3-4. The current which I think is fully working, the previous kernel just in case I discover I was wrong and had forgotten to test something vital, and the new kernel which I am in the process of installing but havn't finished testing enough to use when doing something important or letting others on the system.. I also have several kernels which boot to different filesystems (eg the old SuSE system because its crypto filesystem is not compatible with the gentoo one) and alternate operating systems such as BSD/Plan9/Inferno/OS-9000 - can't think of any others worth running just now ;) But being different filesystems, they arn't relevent to the /usr/src/linux link question. Regards, DigbyT -- Digby R. S. Tarvin [EMAIL PROTECTED] http://www.digbyt.com -- gentoo-user@gentoo.org mailing list
