Re: Best way to configure Linux kernel for a machine
On Wed, 16 Jan 2013 17:47:08 +0530, Shraddha Kamat said: > I normally do the kernel configuration on my machine like this - > > * copy the distro configuration file to the kernel dir > * make menuconfig (answer Y's/N's/M's) Normally keep return key pressed > for default answers > * then do the actual kernel compilation > > > Now, I know that this is not a clean way to do the kernel compilation > (although it has worked for me for thousands of times that I have > compiled and successfully booted up with the kernel - without any issues > - whatsoever !) > > But this time , I am bent upon coming up with a configuration > specifically targeted to my machine. What is the best way to do this ? Take your distro kernel, boot it up. Make sure to insert any USB storage, webcams, etc, at least long enough for udev to recognize them and load their driver modules. Then cd to your kernel source tree and 'make localmodconfig'. That will build a stripped-down kernel that only builds those modules that are currently listed in 'lsmod' (which on my laptop is on the order of 1/3 the size of the full Fedora 'allmodconfig'). Which is why it's important you get all the modules probed - if you don't plug in that USB storage, the module won't be loaded, so it won't be in lsmod, and won't be included in your new kernel - at which point you'll use some bad language as you try to debug why it doesn't work. :) Also, see the other reply that points at Greg HK's talk. > Also, while creating a initrd image > > # mkinitrd /boot/initramfs.img 3.8.0-rc3+ -f > ERROR: modinfo: could not find module ipt_MASQUERADE > ERROR: modinfo: could not find module iptable_nat > ERROR: modinfo: could not find module nf_nat > ERROR: modinfo: could not find module snd_hda_codec_intelhdmi > ERROR: modinfo: could not find module joydev > > I got the above errors - I know how to resolve these errors , but want > to understand why in the first place mkinitrd should complain in the > first place ?? Because if the module was for your keyboard or hard drive or video, and you got an unbootable kernel as a result, you *really* want to know at mkinitrd time, not at boot time... :) pgpErktqN8pyb.pgp Description: PGP signature ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Best way to configure Linux kernel for a machine
On Wed, Jan 16, 2013 at 7:17 AM, Shraddha Kamat wrote: > I normally do the kernel configuration on my machine like this - > > * copy the distro configuration file to the kernel dir > * make menuconfig (answer Y's/N's/M's) Normally keep return key pressed > for default answers > * then do the actual kernel compilation > > > Now, I know that this is not a clean way to do the kernel compilation > (although it has worked for me for thousands of times that I have > compiled and successfully booted up with the kernel - without any issues > - whatsoever !) > > But this time , I am bent upon coming up with a configuration > specifically targeted to my machine. What is the best way to do this ? Hi Shraddha, your story is almost identical to mine. Although, I successfully moved to the next chapter and I can surely share what I learned and how I worked. I do not believe this is the best way, after all I'm still just a noob. ;) Oh and... I hope the contents of my email can be a sufficient excuse for its length! I'm giving my experience, my method and the reasons behind my choices and moves. I just hope reading this wont cause a buffer overflow somewhere in your frontal cortex! ;) I started very very long ago with Redhat (before year 2000), then I moved to slackware and stayed there for a longer while. All this time I was using the defaults provided by the distros. Then, perhaps around 2008, I tried Slax and became very avid for fine tuning and customizing everything. During my research I found the Gentoo distribution, switched over, loved it and migrated all my computers over to it. In the process I copied the ".config" file from my previous stable install (I think it came from slackware) to all my machines (at the time, they were all intel, single core). Soon after, I added a quad-core, then an old AMD athlon, and later (and last) I bought a AMD 64bit dual-core laptop. I used my 32bit distribution and the same old 32bit kernel on that 64bit machine, until I decided this whole situation was no longer tenable. I needed 64bit, I needed better that 386, I needed SMP, I wanted to get rid of all those device drivers I will never ever use... and more... If I read your post right, this is where you stand now. So here's what I did: The first thing was to start doing the same old way, but now using git to get kernel updates. Once I got used to it, the next step was to setup a new branch in my git repository on each machine and configured it to update that branch from one of my computer that I dedicated as the "authoritative" repository. Then I noticed it doesn't quite work to take the 32bit config I had and simply switch it to a 64bit architecture using menuconfig (really, don't even try, there's lots of options to change, none of which are evident to the newbie). So, on each machine I did a "make i386_defconfig" on the 32bit systems and "make x86_64_defconfig" on the 64bit one. I made a commit of those .config files on each machine as the starting point of my new configuration and I started compiling. Then I rebooted and gave it a try. Of course it didn't work and couldn't even boot up to init! So on each machine I checked what the immediate problem was and applied the most minimal correction to my .config (using menuconfig) and making a new commit after the change. Some of the changes could be shared among some of my machines so I pulled (aka merged) those commits onto the other systems' config. Each commit or small group of commits would represent one feature I needed to add on a machine. The commit messages were like "Adding support for USB 1 and 2", then the next would be "Fixing support for USB block devices (usbkeys)", etc... This process was long and difficult but I got excellent help on irc.freenode.net (in ##linux and #gentoo, thanks guys!). The reason it was difficult was my lack of knowledge of the complex interdependencies of various things I needed. But fortunately, the needs that I had were very precise, the errors I got were very clear, therefore my questions were very well stated, and the answers came easilly and clearly (oh and pretty quickly too, except on Friday and Saturday nights, hehe). Within about week, it was done. Everything was supported on each machine (and nothing more), everything was very stable (the video card was the only thing that kept giving me trouble). This led to a totally different configuration on each machine, with a single way of handling them all in the exact same way (with git). The kernel bzImage shrunk to around 50% what it was before (I dropped support for so many unused network cards and other stuff)! I also decided to make all these "features" built into the kernel (as opposed to modules). And left the very minimum as module (actually only 1 or 2 modules I seldom used and were not needed at boot time). The result was a kernel that no longer required an initrd to boot, which made the whole process even simpler. Keeping it up-
Re: Best way to configure Linux kernel for a machine
Sorry, my email client somewhat broke... On 16 January 2013 21:22, Leonid V. Fedorenchik wrote: > On Wed, 16 Jan 2013 17:47:08 +0530 > Shraddha Kamat wrote: > > > I normally do the kernel configuration on my machine like this - > > > > * copy the distro configuration file to the kernel dir > > * make menuconfig (answer Y's/N's/M's) Normally keep return key > > pressed for default answers > > * then do the actual kernel compilation > > > > > > Now, I know that this is not a clean way to do the kernel compilation > > (although it has worked for me for thousands of times that I have > > compiled and successfully booted up with the kernel - without any > > issues > > - whatsoever !) > > > > But this time , I am bent upon coming up with a configuration > > specifically targeted to my machine. What is the best way to do this ? > > > > Although I am not professional in this, I would suggest to read Linux > Kernel in a Nutshell by Greg Kroah-Hartman which is available online > at http://www.kroah.com/lkn/ . Specifically, Chapter 8 provides good > details about custom configurations. > > Hope this helps. > > > > > Also, while creating a initrd image > > > > # mkinitrd /boot/initramfs.img 3.8.0-rc3+ -f > > ERROR: modinfo: could not find module ipt_MASQUERADE > > ERROR: modinfo: could not find module iptable_nat > > ERROR: modinfo: could not find module nf_nat > > ERROR: modinfo: could not find module snd_hda_codec_intelhdmi > > ERROR: modinfo: could not find module joydev > > > > I got the above errors - I know how to resolve these errors , but want > > to understand why in the first place mkinitrd should complain in the > > first place ?? > > > > Thanks list for help for all these years. > > > > -- Shraddha > > > > > > > > ___ > > Kernelnewbies mailing list > > Kernelnewbies@kernelnewbies.org > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > Leonid V. Fedorenchik > ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Best way to configure Linux kernel for a machine
I normally do the kernel configuration on my machine like this - * copy the distro configuration file to the kernel dir * make menuconfig (answer Y's/N's/M's) Normally keep return key pressed for default answers * then do the actual kernel compilation Now, I know that this is not a clean way to do the kernel compilation (although it has worked for me for thousands of times that I have compiled and successfully booted up with the kernel - without any issues - whatsoever !) But this time , I am bent upon coming up with a configuration specifically targeted to my machine. What is the best way to do this ? Also, while creating a initrd image # mkinitrd /boot/initramfs.img 3.8.0-rc3+ -f ERROR: modinfo: could not find module ipt_MASQUERADE ERROR: modinfo: could not find module iptable_nat ERROR: modinfo: could not find module nf_nat ERROR: modinfo: could not find module snd_hda_codec_intelhdmi ERROR: modinfo: could not find module joydev I got the above errors - I know how to resolve these errors , but want to understand why in the first place mkinitrd should complain in the first place ?? Thanks list for help for all these years. -- Shraddha ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
