T42 won't boot with 2.6.32 Linux PAE kernel

mike004 · **Posted:** Sat Dec 24, 2011 9:19 am

Thinkpad T42, 1 gig of memory.

I was using the T42 OK with a 2.6.18 non-PAE Linux kernel.

Now I tried to upgrade to a 2.6.32 kernel. But it looks like PAE is built in to this kernel, and the T42 refuses to boot with the 2.6.32 kernel.

I don't think the T42 processor supports PAE:

$ more /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 13
model name : Intel(R) Pentium(R) M processor 1.70GHz
stepping : 6
cpu MHz : 1694.560
cache size : 2048 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr mce cx8 mtrr pge mca cmov pat clflush d
ts acpi mmx fxsr sse sse2 ss tm pbe up est tm2

So I need to either make my T42 CPU understand PAE (this may be impossible).
Or is there a boot loader option I can specify in /etc/grub.conf to turn off PAE in the kernel?

Thanks,
Mike

Neil · **Posted:** Sat Dec 24, 2011 9:27 am

Hey, welcome to the forum! The kernel you are trying to use is meant for PCs with 4GB+ RAM. Rather than trying to change your CPU to fit (don't think it can be done), why not just use a kernel that works with your hardware?

mike004 · **Posted:** Sat Dec 24, 2011 12:43 pm

Thanks for your reply.

Are there 2.6.32 kernels available that don't have PAE enabled?
Maybe I can compile my own non-PAE 2.6.32 kernel?

Or maybe it's easiest to stick to my 2.6.18 kernel.

RealBlackStuff · **Posted:** Sat Dec 24, 2011 1:35 pm

We have a Linux forum for questions like yours!

GomJabbar · **Joined:** Tue Jun 07, 2005 6:57 am **Posts:** 9622

I moved your new thread out of sight (no replies yet) and moved this one here from the ThinkPad T4x Series forum.

Volker · **Posted:** Tue Dec 27, 2011 6:18 am

There is no command line option to disable PAE as far as I know. Which distribution are you using? I thought all of them have a PAE and a non-PAE kernel to choose from (Fedora certainly has). Of course you can always compile your kernel, but on your CPU its probably faster to get a pre-built one ;-)

mike004 · **Posted:** Tue Dec 27, 2011 9:27 am

Volker wrote:

There is no command line option to disable PAE as far as I know. Which distribution are you using? I thought all of them have a PAE and a non-PAE kernel to choose from (Fedora certainly has). Of course you can always compile your kernel, but on your CPU its probably faster to get a pre-built one ;-)

I'm using Oracle Linux.
2.6.18 had two kernel RPMS, one with PAE, one without PAE.
But it looks like PAE is built into 2.6.32 automatically.

Volker · **Posted:** Wed Dec 28, 2011 4:12 pm

mike004 wrote:

I'm using Oracle Linux.

Oracle Linux is just a repackaged Redhat Enterprise Linux. Starting with RHEL 6, a PAE-enabled processor is a minimum requirement. It seems like you have to recompile or use a Fedora kernel.

mike004 · **Posted:** Wed Dec 28, 2011 4:35 pm

Thanks for your reply.
Is RHEL 6 = 2.6.32 kernel?
Oracle call this kernel OEL 5.7!

Anyway looks like the processor in the T42 won't run a PAE kernel:
Intel Pentium M processor 1.70GHz

T42 won't boot with 2.6.32 Linux PAE kernel

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