kernel 2.6.10 with no modules

fuzzhead85 · 01-21-2005, 06:48 PM

i have an assignement for one of my classes to compile a kernel with no modules, and ive gotten that much done fine, but when i do a make install, it fails on mkinitrd, i dont know what the initrd file does, which may be the source of my problems. so i manually add the kernel i created to lilo, with no initrd entry, everything runs fine, till it gets to mandrakes interactive startup, where it tries to load modules that were not created, then im brought to the graphical login screen but none of my input works, any help would be appriciated, thanks.
-Ian

sgrayban · 01-21-2005, 10:00 PM

First you have to have atleast the fs mods and devfs mods compiled in or it will not boot.

Second using man to see what mkinitrd does I find:

MKINITRD(8) MKINITRD(8)

NAME
mkinitrd - creates initial ramdisk images for preloading modules

bunnadik · 01-22-2005, 05:47 AM

If you compile your own kernel you have to include support for initrd (ram disk) or devfs.

MDK 10.1 uses udev instead of devfs, so if you want to be "pure" you have to have an initrd loading udev
to have some basic /dev entries before everything starts.
In this case you can take the existing /boot/initrd.img and do:

Code:

zcat /boot/initrd.img > /tmp/init.img
mkdir /tmp/init && mount -o loop  /tmp/init.img  /tmp/init
vi /tmp/init/linuxrc (remove all the "echo Loading.... and insmod... entries)
rm /tmp/init/lib/*
umount /tmp/init
gzip /tmp/init.img
mv /tmp/init.img.gz /boot/initrd-nomodules.img

Then add /boot/initrd-nomodules.img to your grub or lilo config.

The other (deprecated) way is to include devfs and make sure it's loaded at boot time.

- Peder

fuzzhead85 · 01-22-2005, 01:30 PM

when i try to execute the zcat line, i get an error that initrd is not in gzip format?

bunnadik · 01-23-2005, 06:26 AM

Weird.
/boot/initrd.img should be a symlink to the acctual initrd file (in the case of MDK 10.1 its usually initrd-2.6.8.1-12mdk.img).
And that file should be gzipped.

You can check with

Code:

file /boot/initrd.img (answer should be "symbolic link to ....")
file /boot/(whatever answer you got previously) (answer shoud be "gzip compressed data...")

If the answer to the second command is "Linux rev 1.0 ext2 filesystem data..." you can replace 'zcat' with 'cp'

- Peder

fuzzhead85 · 01-23-2005, 12:42 PM

ah, i was trying to do it with the initrd for 2.6.10

now everything works fine up until the mount command, then it gives me a seg.fault, any ideas?

fuzzhead85 · 01-23-2005, 12:47 PM

nevermind, must have been a typo or something

fuzzhead85 · 01-23-2005, 01:13 PM

well all those steps worked well, but what does mandrake load after initrd, because whatever that step is, its trying to load usb modules and some other stuff, im not really familiar with linux's boot sequence so any help would be great

sgrayban · 01-24-2005, 01:36 AM

read the kernel docs -- its explained very well

bunnadik · 01-24-2005, 01:51 AM

After boot it runs /etc/rc.sysinit, and after that in runs the S-files in /etc/rcX.d where X is the runlevel you have in /etc/inittab (which
in your case should be /etc/rc5.d and "id:5:initdefault:" )

- Peder