missing modules

[rda918]

i am running slackware 9.1 kernel 2.4.20

i tried to upgrade to kernel-2.6.0
but it didnt work
now my usb mouse isnt working under kernel 2.4.0
and i know why
it cant find module "hid" at boot time
i tried recompiling several kernels and doing a "make modules" and a "make modules_install" to get the modules in /lib/modules/
but they are not in there

what happened to my modules?

[DerekKraan]

Did you symlink /usr/src/linux to /usr/src/linux-2.6.0? Make sure you compiled HID support as a module if you want it that way. You can compile it into the kernel if you want also.

[Hayl]

what kernel source is you /usr/src/linux symlink pointing to now?

[rda918]

aighheeeeeee

my /usr/src/linux is pointing to the dir /usr/src/linux-2.4.23

that is the only folder in that dir. i dont have the original 2.4.20 source...
(i removed everything 'cleaning up')
how much trouble am i in?

[DerekKraan]

No trouble if you can still boot.

Try pointing /usr/src/linux to the folder of your new kernel.

[rda918]

i am having other non-related problems with my kernel right now
but thank you everyone for your tips

i do however wish to understand where modules are stored in linux
is it /usr/src/linux? or /lib/modules or something else?

are there differences between modules 2.4.x and 2.6.x ?
differences being...
installing/managing/executing
i am just curious and cant find much help on modules

also... what does the system.map file do?
when i upgraded to slack 9.1 it put in a new system.map file but i dont use it because the kernel that was installed didnt work
is "system.map" required to boot
it sounds kinda important but i havent noticed it being used at all
i find it kind of odd that ive never had to replace this file when recompiling kernels. whats its use?

sorry to be so off the wall w/ my questions
and thank you to everyone for the tips

[bwkaz]

In order to use kernel 2.6 modules, you need to replace your modutils executables with ones from module-init-tools.

Installation instructions can be found here, just make sure you only ever run "make moveold" ONCE!

/usr/src/linux has nothing to do with the modules, either. The modules_install target in the kernel Makefile looks at the version of kernel that you're compiling, and copies the modules to directories under /lib/modules/<that version>/. It then creates a symlink named "build" that points at the real path to your kernel sources (i.e., it resolves symlinks as it goes, so if you compile the kernel from inside /usr/src/linux when /usr/src/linux points at linux-2.6.1, then the build symlink will point at /usr/src/linux-2.6.1).

But the build symlink isn't used by anything other than external kernel modules anyway; it doesn't affect your ability to load modules.

I am pretty sure you need module-init-tools to be able to build (or maybe install) 2.6 kernel modules anyway. That's why it's listed in Documentation/Changes (you did read that, right?).

As for System.map, it's not as critical (I don't think anyway) on kernel 2.6, because kernel 2.6 decodes oops reports internally. Older kernels need it to decode any problems with the kernel (when it logs an oops, you use a program called ksymoops to turn the addresses into function names -- it uses System.map to do this).

I still put System.map into /boot, though.