Kernel for Intel Atom N270: Processor family, SMP

Anton_G · 09-25-2008, 06:32 AM

Hi, I'm configuring vanilla kernel 2.6.27-rc6 on Asus EEE 901 netbook running gentoo.

Here is /proc/cpuinfo:

Quote:

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 28
model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz
stepping : 2
cpu MHz : 1600.000
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc pni monitor ds_cpl est tm2 ssse3 xtpr lahf_lm
bogomips : 3203.25
clflush size : 64

The question is, what processor family should I select in kernel?

According to gentoo wiki safe Cflags for Intel Atom N270 are:

Quote:

CHOST="i686-pc-linux-gnu"
CFLAGS="-march=prescott -O2 -pipe -fomit-frame-pointer"
CXXFLAGS="${CFLAGS}"

Pentium 4 (Prescott) has the same -march, as well as similar "flags" in /proc/cpuinfo. On the other hand, default Xandros that comes with eee901 uses

Quote:

CONFIG_MPENTIUMM=y

So, I'm not sure what to choose. Linux starts with "Pentium M" as well as with "Pentium 4" without errors.

I have also discovered, that default Xandros uses

Quote:

# CONFIG_SMP is not set

It's a bit strange for me, as Atom actually has HyperThreading support. Why has Asus chosen to disable it?

It's my first custom kernel and I have no clear idea of what does these options actually mean. I will appreciate any help with this questions. If there are links to info about what is hidden under each of them, I would gladly read it.

Thanks, Anton

PS Sorry for my English.

Dj.r4iDeN · 09-26-2008, 12:17 AM

im sure its not P4 or M

atom is new Processor

Anton_G · 09-26-2008, 04:49 AM

Okay, but there is no option "Atom" in kernel config. One have to choose between existing processor families. But what is the closest one? What should I take into account choosing it?

lylemwood · 04-15-2009, 09:47 AM

Gents,

I just recompiled my stock Slackware install kernel with Core2 selected due to the help for the CPU type in the kernel config.

Go to the Core2 and select help or just read below if you're in xconfig and you'll see:

"Select this for Intel Core 2 and new Core 2 Xeons ... You can distinguish newer from older Xeons by the CPU family in /proc/cpuinfo. Newer ones have 6 and older ones 15..."

Taking a hunch and assuming I could always back out by having both selectable on boot up with LILO, I selected the Core2/newer Xeon option, took off Generic X86 support, and then made my other mods and recompiled, deployed, booted, and it's running fine now.

Just putting my modules in as necessary and I'll be off to the races in no time!

Good luck,

HTH,

Lyle M. Wood

lylemwood · 08-20-2010, 07:21 AM

Hello all,

I recently rebuilt my ATOM-powered Aspire ONE and noticed that ATOM is now a CPU type that is selectable.

If you've updated your kernels recently or reinstalled, please ensure you view all options.

I'm pretty sure this thread is dead, but I just wanted to bring everyone into the loop in case they haven't had a chance.

Enjoy!