[MinnowBoard] Problem reading CPU temp in linux (yocto build)

[Gerard Bucas]

Hi Everyone,

We use linux (custom built with yocto project) on minnowBoard MAX. Works great!

However, I have a problem reading the CPU core temperature of the E3825. 
When I use this command line:

cat /sys/class/thermal/thermal_zone0/temp

It ALWAYS returns the value: 26800 (= 26.8C)

Linux kernel version: 3.19.2-yocto-standard

Build Configuration:
BB_VERSION        = "1.27.0"
BUILD_SYS         = "x86_64-linux"
NATIVELSBSTRING   = "Ubuntu-14.04"
TARGET_SYS        = "x86_64-poky-linux"
MACHINE           = "intel-corei7-64" (recommended by Intel for Atom E38XX SoC & minnowBoard MAX)
DISTRO            = "poky"
DISTRO_VERSION    = "1.8+snapshot-20150429"

It looks like this value is hard-coded in the kernel! In researching this on the internet it seems that many people have this problem with a variety of Intel based CPU's/SoC's on a variety of different linux distributions. 

Has anyone else solved this problem or do you know of another linux command line that would give me the CPU (chip) temperature?

I have tried to add the "lm-sensors" package but have had problems adding it to my yocto build as I can't seem to find the right "package group" that includes lm-sensors.
Any ideas/help would be MUCH appreciated!

Thanks
Gerard