More than 1 kernel

VeXocide · Posted: Wed Dec 08, 2004 9:20 am Post subject: More than 1 kernel

I would like to install 2 kernels (gentoo-dev-sources (which i have now) and the gentoo-sources). But what sould i do with the System.map file ?, and what sould /usr/src/linux point to ?

eqxro · Posted: Wed Dec 08, 2004 9:40 am Post subject:

To build my kernel, I issue a make menuconfig; make; make modules_install; make install. The latter make takes care of System.map, vmlinux, kernel, config files, so when I swap the kernels, the system.map always points to the running kernel. Ditto for kernel.h & config, so your only worry is to have the two kernels set up right in the boot loader.

/usr/src/linux should point to the kernel you use more frequently. This is only needed when compiling kernel-source dependent apps (or drivers, like the NVIDIA module), as they expect to find in /usr/src/linux the sources used to compile the running kernel.

Sometimes you can pass options to the compiling scripts to use an alternate /usr/src/linux* directory.

A word of advice... when switching kernels, if using the NVIDIA driver, you'd have to reinstall the module whenever you switch, as the module built on the previous kernel would fail to initialize on the new kernel, therefore needing to reinstall the driver, which implies uninstallation of the previous driver.

adaptr · Posted: Wed Dec 08, 2004 9:42 am Post subject:

The system.map file is only useful after a kernel dump; it contains the symbol names so you can do a proper trace of the core dump afterwards.
Not needed for normal operation.

As for the symlink: /usr/src/linux must always point to the kernel you are working on.
Not the one you are running - that is irrelevant.
If it doesn't point to the kernel you are currently compiling then everything will pretty much.. break.

I would also suggest renaming the kernel to something descriptive, i.e. my kernels are called kernel-2.6.9-r6-1 and kernel-2.6.9-r6-2, with their associated configs saved as config-2.6.9-r6-1 and -2.
Adjust grub.conf to match.
_________________
>>> emerge (3 of 7) mcse/70-293 to /
Essential tools: gentoolkit eix profuse screen

VeXocide · Posted: Wed Dec 08, 2004 9:46 am Post subject:

I don't like the make install (i'd rather do it myself), the kernel already has a descriptional name, but can you have like 2 system.maps like System.map-Kernel-2.4.something and System.map-Kernel-2.6.5 ?

Oh, and i'm not using Nvidia or anything so that souldn't be a problem

bet1m · Posted: Wed Dec 08, 2004 11:33 am Post subject:

dont copy system.map

I never copy

- bet1m

VeXocide · Posted: Wed Dec 08, 2004 3:36 pm Post subject:

k, so that's solved

, tnx