Kernel Power

Contents

Kernel for Power Users

The enhanced kernel "kernel-power" is compatible with PR1.2, contain lots of additional features (IPv6, NAT etc) and bugfixes. The kernel can be installed via Application manager from the System section. Installation of the customization package Kernel-Power-Settings is sufficient, as it depends on the kernel page.

The custom kernel contains additional modules for IPv6, packet filtering, QoS, NAT, tunneling, kernel configuration, Wifi mesh networking, builtin ext3 for booting from other media, ext4, XFS, reiserfs, NTFS read support, ISO9660, UDF, CIFS, automounter, squashfs, unionfs, device mapper and dm-loop, cryptography, cryptoloop, EFI partitions, UTF8 codepages, mouse+joystick input, PPP, PPTP, serial support, USB/IP and generic USB device drivers, battery info, overclocking and kexec support.

Note: This page is under construction and based on the overclocking/undervolting instructions. Hence the heavy bias to overclocking. For overclocking it includes a large set of possible frequencies (125MHz-1.15GHz) which you manually set and try out without flashing a new kernel. The defaults are set to the standard 250-600MHz range. You can also fine tine the voltages for your device for power-saving. Every device is different.

talk.maemo.org: Discussion of the enhanced kernel

Changes between versions are announced on the garage page.

Installation of the kernel

Note: all commands on this page must be run as root in X Terminal (install rootsh package and enter "sudo gainroot")

Installation of the stable kernel from extras

With this kernel you can change the frequency limits, the voltages and DSP frequencies online. It requires firmware PR1.1 or newer.

  1. Install the package kernel-power-settings (section system in Application manager). It will automatically also install kernel-power-flasher.
  2. shutdown and boot again. There's no need for reflashing etc.

See below for configuration information

Installation of the experimental kernel from extras-devel

This kernel version contains additional experimental features and patches. Changelogs are posted on Garage.

  1. Install the package "Enhanced kernel for power users" (section system in HAM).
  2. shutdown and boot again. There's no need for reflashing etc.

See below for configuration information

Verification of proper installation

First verify, that the kernel is actually running: 

uname -r

should return "2.6.28.10power-omap1" or "2.6.28.10power<version>-omap1" If it does not, you should reboot or try to install again 

apt-get install --reinstall -y kernel-power kernel-power-flasher

reboot, and test again.

Upgrade from older versions (< maemo24)

The kernel package was previously called kernel-flasher-maemo. Unfortunately Application Manager does not support package transitions. If you have one of the older packages installed it is recommended that you upgrade in X Terminal 

sudo gainroot
apt-get install -y kernel-power-flasher
apt-get remove kernel-flasher-maemo

If the new kernel still doesn't boot up, try 

apt-get install --reinstall -y kernel-power kernel-power-flasher

Also try other hints for deinstalling the old package.

Make sure you reset /etc/pmconfig to the defaults: 

# Power management configuration file
enable_off_mode 1
sleep_while_idle 1
sr_vdd1_autocomp 0
sr_vdd2_autocomp 0
clocks_off_while_idle 1
voltage_off_while_idle 1
scaling_governor ondemand
scaling_max_freq 600000
scaling_min_freq 125000
sleep_ind 1

Deinstallation

Do not try to deinstall the package in Application Manager! It does not work.

For all kernels the safest method for deinstallation is the following:

  1. make sure you have a working Internet connection (and possibly wait a little bit until the updates are downloaded)
  2. make sure the package rootsh (Section system) is installed
  3. close Application manager
  4. execute the following in X-Terminal 
sudo gainroot
apt-get install --reinstall -y kernel kernel-flasher
  1. if it finishes successfully (with "SIGTERM received" and "Image flashed successfully" messages) then you can continue with 
apt-get remove -y kernel-power kernel-power-modules
  1. after successful deinstallation the comand "ls -l /lib/modules/current" should show 
... /lib/modules/current -> 2.6.28-omap1
  1. shutdown (without USB cable or charger connected) and boot again
  2. your device should now be running the stock kernel

If the device fails to boot or you have other problems, perform the deinstallation from PC with USB cable and flasher utility:

  1. Make sure you have a version 28 or later from extras-testing installed (it fixes the broken /sbin/preinit)
  2. for older versions it is not guaranteed that this method will work without a complete reflash.
  3. execute the following on your PC (see this for more details) 
flasher-3.5 -f --flash-only=kernel -R -F <firmware-image>

The firmware image file could be, for example, RX-51_2009SE_3.2010.02-8_PR_COMBINED_MR0_ARM.bin This is only way of deinstallation with leaked release 1.2 firmware.

If you have the kernel from extras-testing (>v27), there is a "Deinstall kernel" application in your menu. This applications is, however, still experimental (for >v27 it is more stable). Only use if have can fall back to reflashing the kernel using the flasher (see below) in case of problems. Read the instructions carefully when you start the deinstall application!

Upgrading to a new PR

Before upgrading, always make a backup. There are two ways of upgrading the firmware to a new Nokia public release (PR):

  1. reflashing the complete firmware via flasher or NSU. This is safest way (especially for PR1.2). In this case you simply reinstall the kernel after the upgrade. The settings should be restored by the backup application.
  2. Over The Air (OTA) upgrade: this upgrades only system components of your device so that you don't need to restore your settings or reinstall applications. see below

OTA upgrade: Disable extras-devel and extras-testing. DIsable autodisconnect if is installed. Perform the upgrade. If the PR does not deliver a new kernel (PR1.1.1) then you're done. If it provides a new kernel (PR1.1 and PR1.2) then you need to reinstall the enhanced kernel with the following commands: 

sudo gainroot
apt-get install --reinstall kernel-power kernel-power-modules kernel-power-flasher

Holding a specific kernel version

If your manually installed kernel should be not upgraded to the one in extras* try this: 

echo kernel-power-flasher hold | dpkg --set-selections
echo kernel-power hold | dpkg --set-selections
echo kernel-power-modules hold | dpkg --set-selections

to unlock the version: 

echo kernel-power-flasher install | dpkg --set-selections
echo kernel-power install | dpkg --set-selections
echo kernel-power-modules install | dpkg --set-selections

Configuring the kernel settings (of the stable version from extras)

These instructions refer to kernel-power-flasher v24 and kernel-power-settings 0.3. This kernel makes it possible to dynamically change the maximum frequency up to 1.15GHz (supported frequencies are 125,250,500,550,600,700,750,805,850,900,950,1000,1100,1150MHz). WARNING: Overclocking may damage your device and is at your own risk! It may void your warranty and destroy your data. You have been warned.

For more details on voltages read Overclocking#Voltage_tables.

Make sure the packages kernel-power-settings and rootsh are installed. All commands need to be run as root user. If you are normal user in X Terminal enter "sudo gainroot".

1) to try a configuration (you can replace "ideal" with default, lv, ulv, xlv or specify a file you created based on the template /usr/share/kernel-power-settings/default ) 

/usr/sbin/kernel-load /usr/share/kernel-power-settings/ideal

Note: do NOT modify the files in /usr/share/kernel-power-settings/! see 'Creating your own configuration: below.

2) to permanently install a default configuration 

rm -f /etc/default/kernel-power
ln -s /usr/share/kernel-power-settings/ideal /etc/default/kernel-power

3) or your own config 

rm -f /etc/default/kernel-power
cp <filename> /etc/default/kernel-power

4) and to immediately apply it 

/usr/sbin/kernel-load

For beginners: first reboot. then try 1) and check whether the device is stable. then do 2).

Creating your own configuration 5) copy the template to your mydocs (when not in mass storage mode) 

cp /usr/share/kernel-power-settings/ideal /home/user/MyDocs/kernel.txt

6) edit the file /home/user/MyDocs/kernel.txt. The defaults are 

#UP_THRESHOLD=75 
#SAMPLING_RATE=150000
VDD1_OPPS_VSEL="30 30 38 48 54 48 60 60 60 60 60 60 60 72 72"
DSP_OPPS_RATE="90 90 180 360 400 430 430 430 430 500 500 500 500 520 520"
MIN_FREQ=250000
MAX_FREQ=599000
SMARTREFLEX_VDD1=0
SMARTREFLEX_VDD2=0

For changing the frequency range change MIN_FREQ/MAX_FREQ (see "Temporary change of the frequency limits" below ). Either edit the file with an editor on your device (e.g., leafpad) or USB mount it to edit it on the PC. unmount and unplug USB. After editing load the configuration with 

/usr/sbin/kernel-load /home/user/MyDocs/kernel.txt

and repeat 6) until you're happy.

7) to permanently install this new configuration 

rm -f /etc/default/kernel-power
cp /home/user/MyDocs/kernel.txt  /etc/default/kernel-power
/usr/sbin/kernel-load

8) to reset the device to the defaults use 

rm -f /etc/default/kernel-power
/usr/sbin/kernel-load /usr/share/kernel-power-settings/default

Note: the package automatically detects whether a certain misconfiguration has caused reboot loop. It your device reboots twice within 5 minutes, it will load the default settings (250-600Mhz) so that you can fix or remove the invalid configuration file. This also means that, when for some reason you manually reboot too quickly (<5min) your configuration will not be loaded. To load it nonetheless run after booting 

/usr/sbin/kernel-load

Temporary change of the frequency limits 

sudo gainroot
echo 250000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
echo 599000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

The last line shows which values were actually set. To set 125MHz use 124999, for 600MHz 599999, for everthing else x000 with x=MHz. This setting takes effect immediately and is cleared with the next reboot.

Permanent configuration of the frequency limits

WARNING: Permanent overclocking is very dangerous!

Install kernel-power-settings and follow the above instructions.

Configuring the kernel settings (of the experimental version from extras-devel)

These instructions refer to kernel-power-flasher >=v25 and kernel-power-settings >=0.5.

The instructions are not yet available but read this for the features and this mini-tutorial in the meantime.

Battery

In kernels version >=maemo20 you can read out the current battery info: 

modprobe bq27x00_battery
cat /sys/class/power_supply/bq27200-0/capacity
cat /sys/class/power_supply/bq27200-0/voltage_now
cat /sys/class/power_supply/bq27200-0/current_now
cat /sys/class/power_supply/bq27200-0/temp
  • 'capacity' value in percentage of battery level.
  • 'voltage_now' value in mV of battery voltage level.
  • 'current_now' value in mA of battery current consumption. (???)
  • 'temp' value in degrees C of battery temperature.

To remove this kernel module use: 

rmmod bq27x00_battery

or reboot.

With kernel-power-settings >=0.6 the module can be loaded on boot. Just execute this once: 

sudo gainroot
echo bq27x00_battery >> /etc/modules

JoikuSpot

seems to work. read this post.

Remarks

  1. even if 125Mhz is disabled, the telephone app will always try to set the minimum freq. to 125Mhz after a phone call, but it is ignored unless you enable 125Mhz.
  2. if you enable 125MHz also set "echo 1 > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/ignore_nice_load" hint
  3. the 125MHz issue
  4. Installing another version of the enhanced kernel will just overwrite the older version. The stock kernel modules are preserved so that you can simply reflash the stock kernel via USB.
  5. If you for some reason get errors like this during removal or installation "rm: cannot remove '/lib/modules/2.6.28.10maemo-lv-omap1/modules.*': No such file or directory".try this workaround. There was a bug in one of the early LV kernels but it should be fixed in more recent versions.
  6. This kernel will not conflict with the future PR1.2 upgrade. The upgrade will, however, overwrite this kernel and you'll have to install it again.
  7. The screen calibration in settings crashes immediately. It is a known bug in the calibration app, not in the kernel. It's mentioned in the kernel package description and is due to additional evdev (joystick,mouse) support. Just calibrate once with the stock kernel before you install the fully featured kernel.
  8. The kernel supports 125MHz but this frequency is disabled by default in avoid_frequencies. In version <25, it is enabled by specifying "124999", in later versions it is disabled in /sys/devices/system/cpu/cpu0/cpufreq/ondemand/avoid_frequencies and can be enabled with 
echo > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/avoid_frequencies

similarily, individual frequencies can be disabled in >=v25 

echo 125000 250000 750000 > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/avoid_frequencies
Retrieved from "http://wiki.maemo.org/Kernel_Power"