Tips for Testing the 2.5 Kernel

Some things to consider before you configure 2.5, and what to do if you encounter a problem.

Okay, now that you actually have been convinced to try the 2.5 Linux kernel (see previous article), how can you test this kernel out. And, what should you do if you have any problems?

First off, before you configure the 2.5 kernel--say, while you are downloading it--go read Dave Jones's excellent "What to Expect from 2.5" document. In that document, pay specific attention to the sections covering the Input Layer, the Framebuffer layer and module information. These sections of the kernel configuration process are the most confusing for newcomers to the 2.5 series. If you don't pay attention, it is very easy to end up with a kernel that either displays nothing on the screen or doesn't accept any input from the keyboard.

After configuring the kernel with the specific hardware you have on your system, build the kernel, install it and reboot. Don't select all the drivers, here; a number of them do not compile because no one seems to have hardware for them anymore. If you've never done this build and install process before, I suggest you read the Linux Kernel HOWTO, which details all of the necessary steps involved. I also do not recommend that 2.5 be the first kernel you ever build on your own. Try the 2.4 kernel first to rule out any operator errors you might come across.

If you do have hardware for a driver that does not build, please report this. Most kernel developers do not have access to a wide range of hardware, so they are apprehensive about fixing drivers they cannot test. If you post your building problem to the linux-kernel or kernel-janitor's mailing list, and if you have the hardware for the driver and are willing to test patches, you should be able to find a willing developer to provide you with updated code.

Now that your 2.5 kernel is up and running, what should you do to test it? It's simple; do the normal tasks you always do on your 2.4 or 2.2 kernels: run X, browse the Web, read e-mail, play games, write documentation, write code and so forth. Every user stresses the operating system in different ways; therefore, there is no one, correct way to test.

So, You Think You've Found a Problem?

If you think you've found a problem, first off, search the past week or so of the linux-kernel mailing list to see if others have had the same problem; a fix already may have been posted. If you do not see anything relevant, try searching the 2.5 kernel bug database for your specific issue. If you still cannot find anything relevant, please create a new bug in the database so the kernel developers can realize there is a problem. From there, the bug will be assigned to someone to look at, and more importantly, it can be found by others having the same problem in the future.

I hope this short mini-article helps people start testing out the 2.5 kernel. Without users testing, there is no way that the kernel can become stable enough for everyone to use in the future.

Greg Kroah-Hartman is currently the Linux USB and PCI Hot Plug kernel maintainer. He works for IBM, doing various Linux kernel-related things.

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2.5.67 hangs - FIXED!

Anonymous's picture

Hello everyone,

thank you for your support. I am now able to boot the kernel successfully. The problem it looks like is the config file corruption. it was picking up config options from my /boot as well as my 2.4.x kernel (which was linked up as linux). so I moved all my config files out of /boot and linked 2.5.67 as 'linux' and lo! I got the options for VT and VGA_CONSOLE etc. back!. so it booted up like a champion.

once again, I am thankful to all of you for helping me.

And while you are at it...

Anonymous's picture

Give RH 9 a whirl. If this is where Linux is going, then we are sure in for an exciting ride!!!

Re: And while you are at it...

Anonymous's picture

Oh, yeah, it's revolutionary!!!!

*Cums with excitement*

Or perhaps not :-P

Please stay on-topic.

Re: And while you are at it...

Anonymous's picture

It's got my wheels turning!!!

2.5 Hangs during boot - FB problem?

Anonymous's picture

Hi,

Inspired by GH's previous article and the great article by Robert Love in this month's LJ, I downloaded 2.5.67 on Friday and tried compiling it. At first I had a couple of compile problems, mostly due to the inclusions of modules that I really didn't need. so I took them out , and now, it compiles successfully every time. I then tried booting it (GRUB) but this is what I get:

Uncompressing kernel...OK. booting kernel

_

where the "_" is a blinking cursor. The screen stays this way till I reboot. Based on this article i am guessing that it's an FB problem. So I went and read Dave Jones's article on what to expect. But he says that nothing much has changed in the FB (atleast to the user). My understanding was that for x86 FB did not play a big part. since my machine is an x86, I am looking for any hints or suggestions. I know this is not a mailing list, however, was just wondering if anyone else had a similar problem and how they fixed it.

TIA.

Re: 2.5 Hangs during boot - probably a solution

Anonymous's picture

I think I got the same problem as you. It hangs right after "Uncompressing kernel... booting linux..." then the problem is that the 2.5.x config scripts (eg make menuconfig) grabs the options from /boot/*config* and that "config" is your config file for the 2.4/2.2 kernel.

So by move/remove /boot/*config* to another place than /boot and then remove the 2.5.x source and extract the source again and now try configure the kernel again will probably solve your problem.

Have a nice day!

N.Kursu - kursu at linux dot se

Re: 2.5 Hangs during boot - probably a solution

Anonymous's picture

This looks a lot like bug #558 in the bug database. Pehaps if this fixes the problem, someone should comment there. I'll probably try it tonight if I get a chance, since I see the problem also.

Re: 2.5 Hangs during boot - probably a solution

Anonymous's picture

hi,

thanks for this reply. I was thinking that this might be the problem. I noticed this behavior the second time I tried compiling it. I didn't try to move the config files from there. I will do so right now and try it.

thanks again!

Re: 2.5 Hangs during boot - probably a solution

Anonymous's picture

And do let us know whether it worked, might help other newbies like me, who are planning to do this too.

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

First make sure you have

CONFIG_INPUT=y

and not

CONFIG_INPUT=m

Then select

CONFIG_VT=y

CONFIG_VT_CONSOLE=y

From a menu interface (menuconfig or xconfig) do as follows:

go to the "Input device support" menu and say "y" to

"Input devices (needed for keyboard, mouse, ...)"

Then go to the "Character devices" menu and say "y" to

"Virtual terminal" and to "Support for console on virtual terminal".

I hope this helps!

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

For me it was not enough. I had to do 1 additional thing:
go into "Graphics support"-->"Console diplay driver support" and say "Y" to "VGA text console support". Optionally say also yess for "video mode selection support". That's what did the trick for me.

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

Hi,

thank you for this, but, I haven't found any VT or VT_CONSOLE in the .config file. I think you are referring to the 2.4.x kernels which do have these things, but not the 2.5.x kernels.

BTW, I do have the correct cpu set.

After searching around last night, I came up w/ a theory. It could be GRUB. I am using 0.90 and the latest is 0.93. perhaps 0.90 is incabable of booting the 2.5.67 kernel. I didn't have time to try this theory, but will try tonight. the kernel make file itself seems to favor LILO (installs vmlinux and system map in /boot - vmlinux is not a bootable format for GRUB 0.90. so I copied the bzImage and tried booting from that instead).

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

You need VT console in 2.5, but it is only selectable if you have CONFIG_INPUT=y

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

One thing that I have done that caused that problem is adding suport for ACPI and APM, try taking that out and see if it will boot. Also make sure your CPU type is correct.

-SeaPig

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

I second this. A CPU type config problem is often the cause for a boot hang after the Uncompressing Linux... line, IIRC.

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

i think you probably have taken care of the video option mentioned inthe other reply... i too had quite a similar problem for an old p120. the response that i got from bugzilla was that i need to give more inputs as to "where" it got stuck. on your part what you could do is probably try inserting a "printk("Hi")" line immediately after a xxx_init() in the init/main.c start_kernel function.... if all this sounds german, sorry, but i tried that out, and my kernel is now functioning (although not because of this method... but that's another long story...), else you could wait for someone else to point out exactly why/where your booting process stops...

Also, frankly, i dont think its an FB problem. FB comes very late in the booting stage, and even if so, atleast the initialization messages do show up....

robins

Re: 2.5 Hangs during boot - FB problem?

Anonymous's picture

Make sure you have 'VGA text console' enabled and built-in to the kernel. It's located in menuconfig -> Graphics support -> Console display driver support -> VGA text console.

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