Acid Guide to compiling Kernel 2.6.10 on Slack 10.1
 

This is a detailed guide to compiling a new kernel version 2.6.10 under a fresh install of Slackware 10.1.

I enjoyed DaOne's little guide and am grateful for his contribution. However, as the total noob I am, in my first kernel compiling experiences I still missed some points I believe some other noobs as me may miss to successfully compiling their new kernel. I am therefore releasing this first 'acid guide' hoping to help out someone, as I was helped by DaOne and various posts' around here. Please do feel free to leave comments on any suggestions / mistakes that you have found in this guide. Forums are all made of this, sharing.

General note: I try and keep this Post #1 updated all the time so that there's no need to go through all the inevitable posts with such a topic. However, feel free to read on and give your own feedbacks.

Now for the guide part. For the purpose of this guide, I'll use version 2.6.10 which at the moment of this writing is the latest kernel release.

Note: even though strictly not necessary, if you are doing a fresh install of Slackware I recommend updating the kernel prior doing anything else, on the first boot after installing Slack (i.e. even before you get the X server configured and running). This is useful since many compiles do rely on the current version of kernel and may need to be reinstalled when upgrading it (for instance, NVIDIA drivers need to be reinstalled after a kernel upgrade).

The following are my recommended points to follow. Definitely not exhaustive. One last thing: this worked for me. It doesn't mean that it will work for you. Upgrading a kernel may result in the total mess up of your system (this sound scary: it is however a normal operation done by most linux users; it is here to ensure you are aware of what you are doing).

Before you begin, download the necessary files and save them to /etc/src:

1. Get the kernel 2.6.10 sources
Slackware 10.1 comes with kernel 2.4.29. You therefore need to download the full sources of the new kernel. You can get them here: linux-2.6.10.tar.bz2 (35MB). This is the .bz2 file format, which is more compressed than the tar.gz one.

2. Get a valid kernel 2.6.10 configuration file
At a certain point you will have to configure your kernel. You may start off with a fresh configuration, however I recommend getting a good starting point by downloading Patrick's excellent configuration file: config-2.6.10.

Now let's start the operations. Let's move into the /usr/src directory (where you have put the two files here above) and decompress the kernel 2.6.10 source code:The Kernel 2.6.10 source code will now be found into the directory /usr/src/linux-2.6.10.

Note: as per Linus Thorvalds, there's a philosophy that if it doesn't have to be done as root it shouldn't be, in order to reduce error / hacking risks. You may consider compiling the kernel on your local home directory and then su to root to move the compiled files. However, I somewhat tend to believe that having a symbolic link /usr/src/linux to /usr/src/kernel-2.6.10 might be needed by some applications / installs that look for the kernel source, and therefore the fastest / easiest way to proceed is as described here below. If you didn't understand a single word of this, you may just as well ignore this note.

Now, delete the symbolic link 'linux' that is under /usr/src and which points to the old kernel source directory and recreate it to point to the new directory:Now the symbolic link 'linux' points to the new kernel source directory.

Move into the directory linux:Prepare the compiling by removing all eventual precedent files (which you shouldn't have since this is your first compiling, isn't it?) :)Now let's start configuring the kernel. There are several tools around, I prefer menuconfig. Start it up:You may now start configuring from scratch, however as I already explained I believe that it is better to load Patrick's configuration file and build on it. In the configuration window, choose the option 'Load an alternate file', an type /usr/src/config-2.6.10 in the box, then click 'ok'. You have now loaded a proper startup configuration file.

Here things can get tricky, since the options that you set here must build the kernel according to the system you are running linux on. Read all available help and be sure to have the correct settings.

Personally, I setup these three additional things:

1. I have an AMD64 processor, therefore under the processors section I select 'AMD64' and leave 'PC-compatible' as architecture.

2. I use SATA disks, therefore I must ensure that these disks are understood by the kernel at boot time or it will not be able to read from it and I would experience a 'Kernel panic' error. To enable SATA support, under Device drivers->SCSI device support I ensure that I have 'SCSI disk' and 'SCSI generic' selected <*> and not loaded in modules [M]. Also, under SCSI Low Level Drivers, I make sure that 'Serial ATA' is <*>, and I ensure that my chipset support is also enabled here (I enabled NVIDIA chipset support since I have a NFORCE one). This is all done since at boot time modules are not loaded yet, therefore I can't have this support on modules (or, as explained, I wouldn't be able to boot).

3. Also, since I've formatted my disks using ReiserFS, I also want to be sure that at boot time the Kernel is able to read from them. To do so, under File systems I enable Reiserfs support <*>.

Thank you db391 for these clues.

4. I have a PS2 mouse, therefore i ensure that under Device Drivers I select all the necessary PS2 and serial port support otherwise my mouse will not work.

5. Finally, I enable ALSA support to allow for my sound card configuration and I ensure to select the driver for my card (SoundBlaster). You may consider in setting this as module <M> instead of compiled into the kernel <*>.

If you do believe that you need to make additional changes, do so. Otherwise, quit and, when prompted, save the file leaving the .config name as it is by default. You have now configured your kernel.

Now, it's time to build the compressed kernel image using the command: You'll have to wait some time here depending on your machine's speed.

Afer a certain time it will finish, and you will have the kernel image into the directory /usr/src/linux/arch/i386/boot/ (do not browse there for now, stay into the /usr/src/linux directory).

Now let's proceed with compiling and the install of the modules by issuing these 2 commands:This will take longer, and the modules will be installed into /lib/modules/**kernel version here**.

We will now create a new boot entry for LILO, so that you can boot in your new kernel but keeping the old kernel still available.

First, we need to put the freshly generated System.map, .config and the compiled kernel image bzImage into the /boot/ directory.

To do so:Now we need to rename the old kernel image (why we do this will become clear when we recreate the virtual links):Now let's create the new LILO entry, modifying its config file (lilo.conf). Open this file in pico, a very simple text editor:Note on pico: as per XavierP post here below, pico is only installed if PINE is installed. If you selected a full install of Slack, you will have it. If not, you may try using 'nano' instead of 'pico', or use any text editor you may be familiar with.

You will see at the end of the lilo.conf file the Windows entry of your boot option, and then the Linux one. Do not touch the Windows entry. We will modify the existing Linux entry and add a new one so that the last two entries of this file look like this:Important note: please do use the appropriate root disk instead of the example /dev/sdb5 which is the partition that I use in my system.

Quit pico by pressing Ctrl-X and say yes to save the file, leave default name unchanged (lilo.conf).

Now, let's activate these changes by running lilo:------------------ Optional Step ------------------

If you wish, you may remove the existing symbolic links to the old kernel files:We can now add the links to the new files:Now these symlinks will point directly to the new compiled files.

-------------- End of Optional Step -------------


We're almost done. Since kernel version 2.6.xx, the file modules.conf is now substituted by the file modprobe.conf, which you normally shouldn't have already, or if you do, it might just as well be empty.

to see if you have it or if it is empty, type: and see if the file contains something. Exit pico, typing Ctrl-X. If the file doesn't contain anything, delete it:(If you receive an error it is simply because you didn't have the file in the first place).

Now let's create a good file from the new kernel:Final step, ensure that you have a /sys directory. If you do not have, create one withYou may now reboot, and at boot select the Slack_2.6.10 option from LILO.

Enjoy.

Acid Juice.

you might tell people that you put pico editor on yourself since it is not included in Slackware at all.............

I guess VI is not good enough for you...........

pico (or actually a link to nano) is on all of my Slackware machines which were originally installed as 9.x and 10.0
Kernel 2.4.39 by default? I think that you meant 2.4.29

320mb: as per davidsrsb post here above, so is on my machine, on a fresh install... btw no need to be so harsh on me i'm just trying to help here :) and i guess vi is less immediate for noobs. just an opinion.

whoops! corrected :)

Pico has been in slackware for a very long time. It certainly is more intuitive than vi. Although at some point EVERYONE should learn to use vi.

Thanks for taking the time to post such a nice thread =) It's nice when people give back to the community.

Pico is only installed in Slackwar if you install PINE (the email program). An alternative, if you don't want Pine, is to track down and install Nano. As another alternative, just use whatever console based text editor you are comfortable with.

Comment added to the guide. Thank you.

May i add that there are much easier ways in doing all of this? as discussed in the "kernel compile guide for 2.6.0" ...

xushi is there something in particular you are thinking of?

Also, there is no need to add
none /sys sysfs defaults 0 0

...in fstab, just create a /sys dir if it does not exists, the /etc/rc.d/rc.S script will mount it for you :

point taken, guide has been modified.

Sorry, yea,

From what i've tried, it's much easier to just edit the Makefile and uncomment "export INSTALL_PATH=/boot" somewhere around line 450. This will save you the trouble of moving everything into /boot, and backing up the older stuff..

For more information about that, just check out both the guides on the top of the forum (2.4 and 2.6).

Keep up the good work.


EDIT:
==============
It's better to backup the old kernal and system.map into Lilo (say as MyKernel.old), instead of removing it. Just incase your new kernel does not work for some reason (and you will get into that problem at some point), you can always chose the last configured kernel and fix the problems, compile again, etc...

acidjuice - when you have (or think you have) a complete and finalised guide, could I ask you to submit it to the Linux Tutorial section?

For simplicity, some could create a /sbin/installkernel script
which contains the kernel install steps

I discovered this feature with doing make help

So after a /sbin/installkernel script created, you just run make
install and it will run your script instead of the default make install
procedure

well...some remarks....
------------
/usr/src# rm linux
/usr/src# ln -s linux-2.6.10 linux
------------

that link is never used, you don't need it.
------------
/usr/src/linux# cd /boot
/boot# rm System.map
/boot# rm config
/boot# rm vmlinuz

/boot# ln -s System.map-2.6.10 System.map
/boot# ln -s config-2.6.10 config
/boot# ln -s vmlinuz-2.6.10 vmlinuz
--------------

i also think those links are not used, as you edit lilo.conf.

egag

Absolutely. However, I personally moved to Slack to try and learn the most I could from linux (in addition to the consideration that this which is a fantastic community :)). I just thought this could learn a little more to the 'hard way' you could do things. Again, just an opinion.Of course, i did read those. I just think that information is all around, and desired a little to centralize it. That's all.thank you, though mine is just a noob work trying to give some help. Hope it does.

I'd be more thank pleased if you feel it can be.

All of which, true. however, these files already exist and point to the old kernel. I just figured it would be better to have them updated to point at the new kernel, just in case other configs depend on these links too.

Here's something i'd like to see included :)

If its safe or not to use
in order to make a package out of your kernel, and have it listed in pkgtool.

The kernel is backed up according to my guide. Just boot using the Slack_2.4.29 option.

I don't know if it is safe or not... maybe some feedback on this will be welcomed. I can update the guide then. It's my idea to keep Post #1 updated so that there's no need to go throught all these posts.

Sorry, i meant to say the 'last known successful kernel' to be backed up, and not the original 2.4.29 one.

The thing is, with the 'export path' business in the Makefile, it automatically backs up the last good kernel configured and enters that in lilo.

Otherwise, just make a note overthere that you don't have to rename the old kernel particularly as 'Slack_2.4.29', but say, something like 'Slack_old' instead.

But it all depends tbh if your tutorial is just based on a person wanting to upgrade his kernel only after a fresh install, or anytime he wants when editing or enabling something and recompiling.

Hope this helps a bit..


EDIT"
==============
Mention that too :)

Point taken, guide is updated. Thank you!
done too :)

well...a quote from Linus Thorvalds:
---------

I would suggest that people who compile new kernels should:

- NOT do so in /usr/src. Leave whatever kernel (probably only the
header files) that the distribution came with there, but don't touch
it.

- compile the kernel in their own home directory, as their very own
selves. No need to be root to compile the kernel. You need to be root
to _install_ the kernel, but that's different.

- not have a single symbolic link in sight (except the one that the
kernel build itself sets up, namely the "linux/include/asm" symlink
that is only used for the internal kernel compile itself)
----------

from: http://uwsg.iu.edu/hypermail/linux/k...07.3/0587.html

and those symlinks in /boot are really just a lot of useless typing.

for the rest this guide is how i compile kernels ( i never edit make-files ),
and it's very good readable.( though i don't say the others are not )
but there are more ways to build a kernel.

i guess everybody will stick to the method that they thrust.

egag

The symlinks in /boot could be useful for lilo users who don't want to re-run lilo at each compilation time (think of the xwmconfig script that link xinitrc on the fly)

well...you have to run lilo after each compilation, the kernel is on a new position on the disk.
you can only skip lilo-editing.
.....and if you edit it anyway , you won't need them.

egag

...and that's one of the reasons i was referring to. but according to egag this is not true. If anyone agrees i might as well remove them from the guide.

From what I understand, lilo reads the disk adress, so if you use symlink, you have to run lilo
so it resolves it and write the original file adress in MBR.

I didn't know that (I use grub)

no, i don't mean it's a bad idea. it won't harm.
but it saves some steps in the whole.

also, people using this guide will get some prob's for sure, and need to check their steps.
leaving it out would also save time when they are trouble shooting.

egag

yeah..grub works different ( don't know how )
i still want to learn how it works , ( all at time ), it seems to have
some extras which lilo doesn't have.

egag

Point taken, guide has been edited to show this step as 'Optional'. thank you!

still i wonder why you're keeping the " /usr/src/linux-symlink " myth alive ?
i know , even reading the howtos on the ati-site , they advice to check it.
but the build-script uses the " /lib/modules/2.6.10/build " link, which is used by everyone.

it's just a tip.
as any step you can skip is just one less to take.

egag

/usr/src/linux is a myth?
and nobody told me :[


actually, i had thought that it didn't have anything to do with
the kernel compilation...but that it was for easy linking to the
source for third party software compilations. oh well...

I dont trust this guy any farther than i can throw him... not to mention his kernel compile proceadures... wait.. nvm disregard that I thought that was Bill Gates :D

either way.. I see no problem compiling a kernel in /usr/src... I also see no problem compiling it as root... maybe if you are hooked up to the net with no firewall.. but I still doubt anything bad can happen. Although it is what he recommends he doesnt provide any reason why you should not do it.

It has to do with the philosophy that if it doesn't have to be done as root it shouldn't be. Less chance for error and other such trouble.

it's adviced in general not to run a Linux system as root.
that's reason enough..
but also , people following this howto will be ( nearly ) new to kernel compiling and maybe even Linux.
as root you can cause alot of prob's , so i wouldn't advice them to run as root.
( just use "su" when needed and "exit" to get out again )

and for the dir ( /usr/src or ~/ ): you'll have to copy a config file into the src-dir as a starting point and
users don't have wite permissions in /usr.


@acidjuice

there's a typo " Now let's start the operations. Let's move into the /usr/etc directory " , i think it has to be " /usr/src "
and as i read it, it's not clear when and how to copy the config file to the source-tree.
maybe add that command also.

egag

oh , acidjuice, just one more thing,

-------------
The following are my recommended points to follow. Definitely not exhaustive. One last thing: this worked for me. It doesn't mean that it will work for you. Upgrading a kernel may result in the total mess up of your system.
--------------

i think that sound really scary......
if someone follows this guide, there's allways the old kernel to boot.
maybe a more general warning that being "root" you can harm the system or so....

just to make people trust this howto ( as they should... :) )

egag

The statutory warning is always necessary :)

this note has been added to the guide.

absolutely. however i prefer a scared noob to an angry noob wanting to bang my head on a wall :)

i've added your remark to the guide :)

thank you.

absolutely. corrected.

I just used this guide to install the 2.6.10 kernel on my system, and it worked great! However, immediately after I tried to install the nvidia drivers and found out that they search for the file /usr/src/linux-2.6.10/.config. It might be appropriate to change the commands from mv to cp when moving the files to /boot to prevent these kinds of problems. The config files are small enough that duplicate copies wouldn't hurt.

Heck of thing you guys are doing here.
I'll be building one of these kernels in a couple weeks.
I can't wait !

Thanks to all involved.

This is the first time I had seen this, my /etc/modprobe.conf now looks much less sparce.

Thanks

Samac

real glad to read it :)you shouldn't leave the old .config as it points to the old kernel, and the driver might therefore not work. i think it actually points to /usr/src/.config. i personally have modified it to point at /usr/src/config instead (which is one of the symlinks in the optional part of the guide). not sure if this is the best way to go, though.

any input on this welcomed, so i can adjust this guide before final release.

Thank you :)

semac, not sure if it is a wise thing to use this if you already have the /etc/modprobe.conf file, or if it's not empty. it is generated on kernel only and will not have any additional driver modifications that you may have added...

.
Agreed--but the nvidia installer gave me an error and would not compile a kernel interface until I copied /boot/config-2.6.10 back to /usr/src/.config. (See the thread "nvidia install error" where we worked out the problem.) I don't know if any other programs would ever need to see this or not.

Looking back at the guide, the optional step doesn't appear to include making a symlink to /usr/src/config. It does have you make one for /boot/config, however. I haven't tried to see if a /usr/src/config link would work with the nvidia installer as opposed to /usr/src/.config.

Also--how different would this guide have to be for other distributions? It seemed to work smoothly enough to me that anyone could follow it step by step and get a new kernel compiled. Maybe people outside the Slackware community could benefit from such a thing. (Admittedly, I haven't checked to see if they exist in other places as well or not.)

I made sure all the items in the old one were included in the new one, so no harm done.

Thanks for the concern though.

Samac

Another way is to just do;
the new kernel will be /boot/vmlinuz