Hi
I am just about to configure the kernel for LFS v6.3 and am unsure as to what "must" be compiled into the kernel - and what can be done as modules?

I read somewhere:-
Is this OK, so I only need to bother with ext3 (everything else modules) or are there general rules that I can follow?

Thanks for any advice





PS. I was going to just compile everything I needed directly into the kernel, but got the impression this was wrong and would make the kernel run slower(?), so I am thinking sound, network drivers etc - should be loaded as modules - does this make any sense?

If you're not using a ramdisk at boot time, then it is recommended that you build both the filesystem that you
use for your root partition, and the disk controller for that disk, into the kernel, instead of having it as a module. Also, everything that can't be built as a module has to be built into the kernel .

I don't think there's anything "wrong" with building everything into the kernel vice as modules. The speed really depends on the arch from what I've read. A better reason to build modules is that you can unload them if something goes haywire.

Hi -

If you genuinely need it, then compiling it directly into the kernel will make the system go (slightly!) faster.

But compiling stuff you *don't* need each and every time you boot into the kernel could easily make the system go noticably slower.

Guideline: if you're not 100% sure, make it a loadable module.

IMHO .. PSM

Many thanks for the quick responses and useful info.

As you may have guessed it's the first time I'm configuring a kernel, and I have downloaded O’Reilly's 'Kernel in a Nutshell' - but it's a fairly big nutshell and I've not got through it all yet.

But with your advice I can carry on and hopefully get this LFS system up and running soon..

Thanks

LFS is quite an adventure... but well worth the trouble.

When I built my (Gentoo) kernel, I determined (from a Knoppix DVD) what drivers were needed by my hardware. I put those drivers into the resident kernel and omitted everything else. In this way, when "my kernel" comes into memory, it has everything needed to run "my system."

What did I put into modules? Cryptographic routines, drivers for removable devices, stuff like that.

I don't like to set up systems that require the "initial ramdisk" approach. I understand of-course why distro writers use it, but for my own systems "I know precisely what I want."

If you have problematic hardware is better to compile as module. For example my sound card needs modprobe -r mycard; modprobe mycard to operate after suspend.

That's a good point: "suspend" can be a problem and many drivers out there are not aware of its implications. Device-initialization needs to be performed a second time since the electrical power has been turned off and back on again. If you have a driver for a non-essential device that is not suspend-friendly, removing and then reloading the module is a way to be sure that the device-initialization step happens (again).