# PANIC: CPU too old for this kernel

## sitsuj

Hi!

I've tried to compile a kernel for a Pentium MMX 200MHz (3 times now), but with no success. Every time the kernel is loaded, this message comes up:  "PANIC: CPU too old for this kernel". I don't know what to do now, I've checked CPU family to MMX, reduced Timer Frequency, but it also didn't help :/ I'd appreciate any help with this problem (either a step by step solution or already compiled kernel). I am using Gentoo 2007.0. Thank you in advance  :Smile: 

Peter

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## John R. Graham

Boot the installation CD and run

```
cat /proc/cpuinfo
```

and tell us what the following values are:vendor_id

cpu family

model

model name

steppingYou can post the whole thing if you like, but do post those items.

- John

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## sitsuj

Thank you for responding so fast  :Smile:  So, here it is:

```

processor : 0

vendor_id : GenuineIntel

cpu family : 5

model : 4

model name : Pentium MMX

stepping : 3

cpu MHz : 200.458

cache size : 0KB

fdiv_bug : no

hlt_bug : no

f00f_bug : no

coma_bug : no

fpu : yes

fpu_exception : yes

cpuid level : 1

wp : yes

flags : fpu vme de pse tsc msr mce cxf mmx up

bogomips : 401.71

```

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## Cyker

0KB cache!?  :Shocked: 

I had Pentium MMX and I'm sure it had more than 0KB cache! (IIRC it had a whopping 32k; Twice as much as a normal Pentium  :Razz: )

If you have set the kernel to Pentium MMX CPU (Which is right), check the CHOST - If it is i686, there is a possibility the i686 built target is causing problems, as the P1 is i586 and some i686 stuff won't work on it  :Sad: 

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## sitsuj

Unfortunately, my CHOST is set properly (this would probably solve my problem  :Smile: ) to "i486-pc-linux-gnu". But maybe I could find a proper kernel on minimal disc or Internet?

Btw, you're right, it should find 32KB cache on CPU. But... whatever  :Very Happy: 

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## John R. Graham

Could you tell us the exact steps you're using to build the kernel?

- John

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## MorpheuS.Ibis

didn't you disable CPU cache in BIOS by some accident? it is really strange for a CPU to have no cache at all (it couldn't work without cache IMHO)

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## Cyker

Oh you can; Remember the first Celerons?

Intel: EDO SIMM RAM means we don't need cache in our budget CPUs anymore!

....

User: Why the hell is it taking Notepad 3 hours to load?

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## sitsuj

 *john_r_graham wrote:*   

> Could you tell us the exact steps you're using to build the kernel?
> 
> 

 

```

cd /usr/src/linux

make menuconfig

```

Hm... I'll just say that I'm not changing anything except mentioned before CPU family.

```

make && make modules_install

```

I'll try to look for some kernels, that are suitable for my CPU on the Internet. Anyway, I'm still waiting for a solution  :Smile: 

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## sitsuj

 *MorpheuS.Ibis wrote:*   

> didn't you disable CPU cache in BIOS by some accident? it is really strange for a CPU to have no cache at all (it couldn't work without cache IMHO)

 

No, of course not  :Very Happy:  But thanks for a clue  :Smile: 

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## eccerr0r

It should work fine...

```
$ cat /proc/cpuinfo

processor       : 0

vendor_id       : GenuineIntel

cpu family      : 5

model           : 4

model name      : Pentium MMX

stepping        : 4

cpu MHz         : 166.097

cache size      : 0 KB

fdiv_bug        : no

hlt_bug         : no

f00f_bug        : no

coma_bug        : no

fpu             : yes

fpu_exception   : yes

cpuid level     : 1

wp              : yes

flags           : fpu vme de pse tsc msr mce cx8 mmx

bogomips        : 332.50

clflush size    : 32

$ uname -a

Linux kagome 2.6.22 #1 Sun Sep 2 21:09:43 MDT 2007 i586 unknown

```

I have these set in my kernel:

```
CONFIG_X86_PC=y

CONFIG_M586MMX=y

CONFIG_X86_GENERIC=y

CONFIG_X86_CMPXCHG=y

CONFIG_X86_L1_CACHE_SHIFT=7

CONFIG_X86_XADD=y

CONFIG_RWSEM_XCHGADD_ALGORITHM=y

CONFIG_GENERIC_CALIBRATE_DELAY=y

CONFIG_X86_PPRO_FENCE=y

CONFIG_X86_F00F_BUG=y

CONFIG_X86_WP_WORKS_OK=y

CONFIG_X86_INVLPG=y

CONFIG_X86_BSWAP=y

CONFIG_X86_POPAD_OK=y

CONFIG_X86_ALIGNMENT_16=y

CONFIG_X86_GOOD_APIC=y

CONFIG_X86_INTEL_USERCOPY=y

CONFIG_X86_TSC=y

CONFIG_X86_MINIMUM_CPU_MODEL=4

```

Odd.  I could have sworn this computer had the F00F bug...

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## sitsuj

This is really weird. Kernels from minimal CD don't work :/ Could you (or anybody, who has successfully compiled similar kernel) send me your kernel? (Rapidshare, etc.)

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## eccerr0r

Sent PM.

If anyone else also ran into this issue and wants to try, please PM.  I'm curious if this fails on any P5's, that would be really weird...

(it's a fairly normal 2.6.22.8 source tarball compiled, 71MB.  Binary+.config+System.map w/o modules is about 1MB.  I "cross compiled" this on my Gentoo box for my sister's Debian router box, it's kind of sad that her box can't compile 2.6 kernels anymore since it uses gcc-2.95.4 ...)

I have another hypothesis to what's wrong:  Are you building a kernel with a x86_64 box?

I'm not sure if I got my x86_64 box to build a proper x86 kernel yet...  Need to do some magic with the makefile or set some target environment variable.

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## John R. Graham

 *sitsuj wrote:*   

> Hm... I'll just say that I'm not changing anything except mentioned before CPU family.
> 
> ```
> 
> make && make modules_install
> ...

 Presumably you're following this up with a "make install" or else copying the images manually to /boot?

When you say that the install CD kernels don't work, do you mean that you get the exact same error message?  This is a clue as you don't get that error message when booting the install CD, right?  Please take steps to verify that you're loading the kernel you're building (i.e., ensure that the file names in grub.conf exactly match your new kernel name).

Finally, changing nothing but the CPU family probably won't result in a usable kernel.  At a minimum, you'll need to ensure that the drivers for your hard drive controller are included.

- John

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## sitsuj

Thank you very much  :Smile: 

As soon as I come back to home, I'll report how it's working  :Smile: 

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## sitsuj

 *john_r_graham wrote:*   

>  *sitsuj wrote:*   Hm... I'll just say that I'm not changing anything except mentioned before CPU family.
> 
> ```
> 
> make && make modules_install
> ...

 

Yes, I get the same message. And that's a little bit weird, because I'm using the kernel, which works perfectly OK when booting from a CD. Every time: "PANIC:..." And yes, I made sure that paths in grub are correct. Let's just wait till I come home and check out the kernel eccerr0r sent me  :Smile: 

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## eccerr0r

 *john_r_graham wrote:*   

> Finally, changing nothing but the CPU family probably won't result in a usable kernel.
> 
> 

 

Yes this is true (though it seems strangely worded.)  Depending on what it's changed to, it indeed can produce an unusable kernel.  I got bit by this by not specifying "generic x86" and trying to boot my P4's kernel on a K7.  It failed miserably - did not even get to init.  IIRC it hung shortly after decompressing the kernel, probably due to an invalid instruction.

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## sitsuj

The kernel you sent me works, but... it does not support reiserfs, so my root partition is not recognized. So thanks for a config file too, I'll try to re-compile the kernel and report after that  :Smile: 

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