Optimize boot time
by Richard Grimmett, Rodolfo Giometti, Charles Hamilton
BeagleBone: Creative Projects for Hobbyists
- BeagleBone: Creative Projects for Hobbyists
- Table of Contents
- BeagleBone: Creative Projects for Hobbyists
- Credits
- Preface
- 1. Module 1
- 1. Setting Up for the First Time
- Introduction
- First boot up
- Power requirements – basic guidelines
- Display
- Essential GNU/Linux commands – the command shell
- Essential GNU/Linux commands – typical commands
- Getting ready
- System navigational command – change your directory – cd
- How to do it…
- There's more…
- System navigational command – show your current directory – pwd
- How to do it…
- System navigational command – find a file – find
- How to do it…
- Device and system insight – shows what's inside a directory – ls
- How to do it…
- Device and system insight – find out what USB devices are connected – lsusb
- How to do it…
- Device and system insight – get information about connected devices – cat/proc/bus/input/devices
- How to do it…
- There's more…
- Device and system insight – get your version of Linux
- How to do it…
- Device and system insight – find out running processes – ps
- How to do it…
- Device and system insight – find out the resources used by running processes – top and htop
- How to do it…
- Device and system insight – quitting processes – kill
- How to do it…
- Device and system insight – message reports – dmesg
- How to do it…
- Device and system insight – shows disk space – df -h
- How to do it…
- Device and system insight – explore network – Ifconfig
- How to do it…
- Modify content / data commands – make a new directory – mkdir
- How to do it…
- Modify content/data commands – remove a file or directory – rm
- How to do it…
- Modify content / data commands – download files – wget
- How to do it…
- There's more…
- Modify content / data commands – open a tar file – tar [options]
- How to do it…
- There's more…
- Modify content / data commands – clean up files – autoclean
- How to do it…
- Modify content / data commands – purge a package – apt-get purge, apt-get remove --purge
- How to do it…
- Modify content/data commands – shutdown the system – [options]
- How to do it…
- See also
- Edit a text file from the command shell
- Connectivity
- Package management – Installing packages using apt-get
- SSH / Remote access
- System images
- 2. Basic Programming Recipes
- 3. Physical Computing Recipes Using JavaScript, the BoneScript Library, and Python
- 4. Exploring GNU/Linux Recipes Using Bash, Autotools, Debugger, and systemd
- Introduction
- The basic shell script
- Epoch Time shell script
- Compile and install
- Compile and install Git from source
- Debugging
- Debug a simple C-code application from the command line using GDB
- Debug an application remotely from Eclipse and GDB server
- systemd services
- Basic commands for systemd services
- Optimize boot time
- Create a systemd service to run at boot time
- 5. Basic Programming Recipes with the Linux Kernel
- Introduction
- Kernel application binary interface
- Installing the latest kernel image
- Installing and building a custom kernel
- Interactions with the kernel – sysfs entries and controlling the GPIOs
- Device Tree and its roots
- Device Tree / basic build
- Device Tree / advanced – adding DT overlay to run a custom cape
- Universal cape overlay
- Running a script to check DT usage on GPIO pins
- 6. Run Faster, Run Real Time
- 7. Applied Recipes – Sound, Picture, and Video
- 8. The Internet of Things
- 9. The Black in Outer Space
- Introduction
- Grabbing the International Space Station flyover data and visualizing it
- Tracking using RTL-SDR
- Airplane tracking with RTL-SDR
- Satellite tracking using GPredict and RTL-SDR
- Satellite tracking using the SatNogs Network client / ground station and RTL-SDR
- Adding other interfaces – ISS tracking and text to speech
- 1. Setting Up for the First Time
- 2. Module 2
- 1. Dangerous Gas Sensors
- 2. Ultrasonic Parking Assistant
- 3. Aquarium Monitor
- 4. Google Docs Weather Station
- 5. WhatsApp Laundry Room Monitor
- 6. Baby Room Sentinel
- 7. Facebook Plant Monitor
- 8. Intrusion Detection System
- 9. Twitter Access Control System with Smart Card and RFID
- 10. A Lights Manager with a TV Remote Controller
- 11. A Wireless Home Controller with Z-Wave
- 3. Module 3
- 1. Preparing the BeagleBone Black
- 2. Building a Basic Tracked Vehicle
- 3. Adding Sensors to Your Tracked Vehicle
- 4. Vision and Image Processing
- 5. Building a Robot that Can Walk
- Building robots that can walk
- Working of servomotors
- Building the quadruped platform
- Using a servo controller to control the servos
- Communicating with the servo controller via a PC
- Connecting the servo controller to the BeagleBone Black
- Creating a program on Linux to control your quadruped
- Issuing voice commands to your quadruped
- Summary
- 6. A Robot that Can Sail
- 7. Using GPS for Navigation
- 8. Measuring Wind Speed – Integrating Analog Sensors
- 9. An Underwater Remotely Operated Vehicle
- 10. A Quadcopter
- 11. An Autonomous Quadcopter
- Bibliography
- Index
You can use systemd to speed up your startup time. This recipe is not a definitive recommendation for which services may be expendable. Instead, it provides the overall method to test the impact of different services on your boot time.
Perform the following steps:
- Navigate to the
systemddirectory (root user) as follows:# cd /lib/systemd/system - Next, determine how long your overall system is taking to get going with the following code:
# systemd-analyze - You can quickly figure out the pokier services. Just point the finger at them with the following command that reveals all the systemd services that are sorted by their boot times:
# systemd-analyze blame - From this output, you can immediately pinpoint some of the culprits. We will assume that you're running the current Debian distro, so you'll see things similar to the following command:
wicd.service (7205ms) apache2.service (3430ms) wpa_supplicant.service (1938ms) ...
- Some of these may be expendable startup services and worth disabling. Experiment by disabling the different services and see how it affects your boot times. Here is an example:
# systemd systemctl disable wicd.service
-
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