Messed up Linux i686
 

I upgraded a while back, or so I thought I was upgrading to "i686" because I was told that I needed to upgrade my kernal in order to get a certain program to run, unfortuantly I downloaded i686.. I am not even sure what that is or why it is different from i383... but problem remains I cannot get in GUI and linux cannot detect my USB, my mouse, my ethernet card... and that is it I think... and it cannot get into Xwindow

the i686 and i386 (i486,and i586 for that matter) come from when you 'compile' your kernel.

the kernel is built with optimized code for different processors i686 being pentium 3/4 (and whatnot). i have never heard of (though i very well could be wront) any programs requiring certain x86 optimizations to run...i beleive either the code is optimized or it's not.

as far as your other problems ...you will have to elaborate on those..you rebuilt your kernel or...?? if you did rebuild your kernel , it's more than likely you have not included (either built in or as modules) the correct 'peices' for these devices to operate

please provide more info

mmm I am not sure what you mean.. I know that once I recompiled my kernal from i386 to i686 everything on my system stopped functioning and I couldnt get into GUI so I assumed they are interconnected. How would I go about changing it back to i386?

you have to find your old kernel image (assuming you didn't *replace* it with your i686 one) else you're gonna have to recompile.

i only used redhat for about 2 days before i went back to slackware (and for good) so i'm not sure on where these files might be located (..maybe /boot) usually named vmlinuz)

now if you know where your old image is then all you have to do is tell your bootloader (either grub {i think that is default RH} or lilo} which one you want to boot)

..do you remember whether or not you backed up (renamed..) your other image maybe to vmlinuz.old or something??

I am positive I did not back anything up, I just installed the new kernel and rebooted and then everything stopped working

well, at least you've learned a valuable lesson...always backup the image before installing a new kernel (that is until you're positive it will work at least with bare functionality, and also add an entry to your bootloader {lilo or grub} for emergancy situations)

i'd say check the redhat cds to see if there's a default image (there should be),on there, but you can't seem to mount a cd. i'm not really sure what you did , or didn't do but it seems you're in a tough spot now...the only other thing i can think of (and i would only do this if you A: have the time and willingness to try again ...and B: dont have anything utterly important on your drive yet) but that would be to REINSTALL!!!!

i would hold off untill maybe one of the gurus might have a better solution...but that's just me

don't sweat it tho...it took me like 6 hours to get my kernel working and to a bare minimum of what *needs* to be compiled in.

good luck

Jeremy,

I have a P4 2.4 Ghz. So you're saying I should install i686 instead of i386? Would that make my system run faster?

I am building a box for someone in 2 days with an AMD 2000+. Which should I get for it?

when building a new kernel (as opposed to *getting* one)...during the (for example...) `make menuconfig` portion of the build , there is a submenu labeld `Processor type and features` where you'll find an option to select for which processor *family* to build the kernel for....

example from 2.4.20 :

386
486
586 / K5 / 5x86 / 6x86 / 6x86MX
Pentium-Classic
Pentium-MMX
Pentium-Pro / Celeron / Pentium-II
Pentium-III / Celeron(Coppermine)
Pentium-4
K6 / K6-II / K6-III
Athlon / Duron / K7
Elan
Crusoe
Winchip-C6
Winchip-2
Winchip-2A / Winchip-3
CyrixIII / VIA-C3 / VIA-C5

you would undoubtedly choose the Pentium-4 option and for your friend the Athlon one i would say...

as far as making it *faster*, yes in some areas i'm sure there would be improvements made...you still run at the same 2.4Ghz (unless you overclock) but a kernel built with the 386 option would not benefit from optimizations that could be made for another type of processor....

i hope that sheds some light on the subject :)

ix86?
 

Jeremy,

I am installing a new installation of Linux tomorrow. We have new mobo, cpu, and video card. The cpu is Athlon 2000+.

I don't understand the difference between "building a new kernel (as opposed to *getting* one)" from your post. My CD's were downloaded from the RedHat ftp site, and i386 seemed to be the only choice. My friend who I will install for has the RH9 box set he bought here. There is nothing I can see on those CD's to indicate these other CPU's either.

Any further explanation would be appreciated. Perhaps this is only a config choice, and I'm complicating it - but I did see the different ix86's you mentioned somewhere - just can't remember. I would like to have the most optimized kernel for my system.

TIA

Building one as opposed to "getting one" means compiling it yourself, or using a binary.

Its like RPM vs. Source.

compiling from source gives you more control and makes it faster, but using a binary is easier.


Most distros come with an already built kernel, but you can at a different point compile your own kernel from source.

Its not too hard. Check the slackware forum for a tutorial.

exactly as contrasutra says...

the binary (the one that comes with your distro (i386)) was probably built with the i386 processor family in mind...reason being is that it will probably work out of the box with most (if not all) x86 processors...

..that kernel probably has some things built in and most of the more common (extra) stuff built as modules to be loaded when the system is poked and proded (probed :) ..(once again ..so most stuff will run outta the box) i think distro makers use 386 sometimes generically...meaning the default kernel would end up being for 386 (until you built your own)..but during the installation it may be determined (or even a choice) to install a different kernel than the default.


....again as contrasutra stated ..there is a kernel compiling howto (if you will) in the slackware forum. word of CAUTION :: until you know that what you're building will work when you reboot your computer ...backup the old kernel (..ie `mv vmlinuz vmlinuz.old`) and add an extra entry in your bootloader config. if you don't understand all of what i just said about the bootloader config and vmlinawhat ...it'll come to you eventually :) it takes time...

uhhhh yeah, good luck, have fun, and don't break anything so that it can't be fixed.

Hey Guys,

I thought I posted this, but it's not here.

Both of you guys use Slackware. Is that kernel compiling how-to tutorial in the Slackware forum going to apply to my RedHat distro?

TIA

yes sir,

it doesn't really matter what distro you use...as long as the distro is based on the linux kernel.

the only thing that may differ is the *default* place to put the kernel (ie: / , /boot ..) and the name of the kernel (ie..vmlinuz,kernel-<version>)... really tho , i could put the kernel up my a$$ after i've built it. as long as i tell my bootloader (lilo , grub...) where to find it ...i'm good to go.

Thanks, Jeremy. Never thought of putting my kernel there - probably won't try that location anyway. It's not that it's not secure, just messy accessing it!

roll your own - again
 

I read the Kernel compiling guide for newbies in the Slackware forum, but still don't quite get it. I think I can follow those instructions, but does this happen *after* I do the basic RH9 install? It comes with 2.4.20-8. I'm sorry to seem to be a no-brainer, but something just seems to be missing in the beginning of the instructions.

TIA