Disabling Pentium+ Support in Linux

[Annoyingrob]

Im trying to install Redhat 6.1 on my ancient 486 laptop, but im running into some difficulties. Im not much of a linux guy, so im kind of stuck. I made an adapor and plugged my laptop hard drive into my home pc, and proceeded to install. The problem was, it was a PII processor, so when i went back to the 486 laptop, linux got angry, and wouldn't load. It didn't know what to do without the "Pentium+" processor. Is there a way to recompile the kernel after i install linux to disable those enhanced instructions?

[chaim79]

Kernel rebuilding is relatively easy.

First, you get the kernel source. go to www.kernel.org and get whatever you want, I would suggest going for a 2.2 or 2.4 kernel, don't go for any kernels that have an odd second number, they are beta kernels. then you unpack into the /usr/src directory (not mandatory, just good sense)

Second, configure the kernel. if you are running xwindows use "make xconfig" if not use "make menuconfig" go through and start selecting what you want and dis-selecting what you don't want. If you have any questions read the help on that option, if you don't have any questions still read the help on an option, it's very smart.

Third, compile the kernel. start with "make dep" then "make bzImage" (which compiles the actual kernel) then "make modules" and "make modules_install" (if you are using modules, you don't have to)

Fourth, install the kernel. go to the directory where bzImage is located. (/usr/src/linux/arch/i386/boot) copy it to your /boot directory and rename it to reflect what it is (with redhat I use vmlinux-2.4.10 you have your choice) next you go back to the /usr/src/linux directory and copy the system.map file over to the /boot directory, and again change the name to show what it is (ie. system.map-2.4.10)

Fifth, configure lilo. go to /etc and open lilo.conf in your favorite editor. add the stuff for your new kernel. make sure you don't touch your old kernel, you want that in case you made a mistake in your configuration of the kernel.

your lilo entry should look like this

image=/boot/vmlinux-2.4.10
label = new
read-only
root=(your hd, should be the same as your other kernel)

There may be some other options, but those are the most important. Now you run lilo to load the configuration. if you get any errors here go back to lilo.conf and try again. after this you get to restart and see if your kernel works

(with a non-graphical lilo) at the lilo prompt hit tab and "linux" and "new" should show up, then type in "new" and hit enter. and cross your fingers. Repeat until you get a working kernel, then once you are satisfied with it delete the old kernel and the lilo.conf entries for it, and the kernel source, no sense wasting space.

If you run into problems feel free to give me an e-mail.

[Annoyingrob]

Hehe, brain overload...must..pay..attention....Bah! Lol,

Thanks for the info. I have actualy devised another plan of attack for installing linuk but i might turn back to recompiling the kernel.

I have a working network card for my laptop, so il try to do an ftp install, while sharing the cdrom on my other computer with an ftp program.

[David]

Do 'make menuconfig' in a console and look at General setup or something (its one of the first few choices) and look for processor type. Change it to 386 for the bare minimum. 486s have some slight optimistations, so you may want to try those.