- Using the instructions Installing and setting up a Raspberry Pi, install Soft-float Debian “wheezy”,
2013-05-29-wheezy-armel(at the time of writing).
- Navigate to the Java SE Downloads and click through JDK and get a copy of Linux ARM v6/v7 Soft Float ABI (
- Copy the file to the Raspberry Pi (from the command line).
scp jdk-7u21-linux-arm-sfp.tgz firstname.lastname@example.org:/home/pi
- Open a PuTTY session to the Raspberry Pi.
- Do my
sudo bashtrick again to open a root shell. This will stop us having to write sudo in front of everything. It also has the handy benefit of separating the history of your sessions with extraneous commands that you wouldn’t normally use.
- Also there now! Create somewhere for Oracle Java to live and uncompress the downloaded zip file.
mkdir -p /opt/java cd /opt/java tar -xvzf /home/pi/jdk-7u21-linux-arm-sfp.tgz
- Now we’ll tell the system about the Oracle Java installation.
update-alternatives –install “/usr/bin/java” “java” “/opt/java/jdk1.7.0_21/bin/java” 1
- We must also tell the system that we want it to use this version of Oracle Java by default.
update-alternatives –set java /opt/java/jdk1.7.0_21/bin/java
- Now test:
root@drswifty:/home/pi# java -version java version “1.7.0_21″ Java™ SE Runtime Environment (build 1.7.0_21-b11) Java HotSpot™ Client VM (build 23.21-b01, mixed mode)
- The Java that has been installed here is the Java Runtime Environment (JRE). So when you type
javeyou’re getting the JRE version and not the Java Development Kit version and as a result you are not getting
javacwither. This is ok because all the applications on the platform will run under it. As developers we need the JDK version so we’ll have to rejig our
PATHenvironment variable so it picks up the JDK’s version of Java before the JRE’s. Edit
~/.bashrcand add the following lines:
export JAVA_HOME=`update-alternatives –list java | sed ’s>/bin/java>>’` export PATH=$JAVA_HOME/bin:$PATH
- Log out and log back in again and you should now have access to the Java Development Kit and the compiler tools e.g.
- Give yourself a pat on the back!
java -version, I received the error:
java: error while loading shared libraries: libjli.so: cannot open shared object file: No such file or directoryA lot of reading later and I discover the problem is caused by a conflict in the binaries used by the operating system and the Oracle
javaexecutable. The Raspberry Pi hardware comes with hardware floating point (HFP) and as a result all the binaries that come with Raspbian “wheezy” take advantage of that. The Oracle
javaexecutable, however was compiled with options that use software-based floating point (SFP). This mismatch means that although the file
JDK_HOME/jre/lib/arm/jli/libjli.soexists, the operating system is unable to understand it properly and as a result continues on it’s search to find one that will work. Eventually it gets to the end of the list and reports that it couldn’t find
libjli.so. So what can be done? Reinstall everything! Oracle does not yet provide a HFP build of Java. The only option is use a special version of Raspbian called Soft-float Debian “wheezy”. Then try installing Java 7 again.
- We need to install the operating system on the SD card. For this we will need to be the root user. You could prefix all the commands with
sudo, but I find it easier just to
sudo bashwhich will run another shell with elevated privileges.
MrN-host:RaspberryPi mrn$ sudo bash Password: bash-3.2#
- Insert the SD card. The Mac will put an icon on the desktop representing the SD cards filesystem. Before anything we need to take control of the SD card.
- On the command line type: mount
/dev/disk0s2 on / (hfs, local, journaled) devfs on /dev (devfs, local, nobrowse) map -hosts on /net (autofs, nosuid, automounted, nobrowse) map auto_home on /home (autofs, automounted, nobrowse) /dev/disk1s1 on /Volumes/NO NAME (msdos, local, nodev, nosuid, noowners)
- The name of the icon on the Desktop was “NO NAME", but it could be different for you if you have renamed the volume. Look for the device with the same name. In my case
- We unmount the SD card:
diskutil umount /dev/disk1s1
- Type mount again and the “NO NAME” device should have disappeared.
/dev/disk1s1is the name of the partition so
/dev/disk1is the name of the SD card’s device. We’ll need that later.
- Now, go to the Raspberry Pi download page and get a copy of the Raspberry Pi operating system. For this example I’ll use the recommended operating system Raspbian “wheezy” (2013-05-25-wheezy-raspbian). If it is possible, get the torrent version; there was 200 in my swarm and it downloaded in a few seconds.
- Unzip the download:
- Now the fun bit. We’re going to lay the downloaded file on to the SD card, well on to its block device. It took 15 minutes to copy the 1.8GB disk image on to the SD card.
# dd if=2013-05-25-wheezy-raspbian.img of=/dev/disk1 bs=1m 1850+0 records in 1850+0 records out 1939865600 bytes transferred in 1128.683885 secs (1718697 bytes/sec)
- The disk image that has been laid down on the SD card contained a single partition which when completely written was recognised by the Mac and automatically mounted. A boot disk icon should appear on the Desktop.
- Drag the boot disk icon to the Trash.
- Pull the card out of the Mac and place into the Raspberry Pi and switch it on.
- Boot up the Raspberry Pi and it should drop you off at a menu screen where we set up a few things.
- First up we will check and install the latest version of the menu screen or raspi-config. Use the up/down keys to go down to 8 Advanced Options and hit return. Now go down to A5 Update. The menu will restart running the latest version.
- Now we’ll configure a few things to help us along the way.
- Most important is to change the default password. Not for any security concerns but because the default password is “raspberry” which is not only too long but also plays havoc with my dyslexia. I can never remember if it’s “bp” or “pb", anyway I digress. I usually just use “pipi". Go into 1. Change User Password and follow the instructions.
- During the course of our installations and set up we may need to reboot a few times so we don’t want it going in to the windows environment each time we do. Switch it off with 3 Enable Boot to Desktop.
- As we are good to the world also consider using 6 Add to Rastrack. It just tells a magic server that you have installed a Raspberry Pi so they can do stats and things. There’s no registration.
- Penultimately go to 8 Advanced Options and then A2 Hostname. The current hostname is raspberrypi which is a bit long. You could end up writing this everywhere. So I’ll just name it after the owner drswifty.
- And finally select 1 Expand Filesystem. This takes the 1.8GB disk image you installed and expands it to fill the whole SD card giving you access to the other 14GB!. This can take a while, about 20 minutes for a 16GB card.
- When you exit with Finish, it will ask you if you want to reboot. Select No. We still need to find out what its IP address is so we can continue remotely from our favourite laptop using PuTTY.
- You will be dropped at the command prompt so issue the command
ifconfig. Your external address will be listed in either the eth0 or wlan0 interfaces.
eth0 Link encap:Ethernet HWaddr b8:27:eb:9b:6b:84 inet addr:192.168.0.13 Bcast:192.168.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:170 errors:0 dropped:0 overruns:0 frame:0 TX packets:113 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:15605 (15.2 KiB) TX bytes:14637 (14.2 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) wlan0 Link encap:Ethernet HWaddr 4c:60:de:61:61:04 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
- Finally, reboot the machine so the hostname change comes into effect.
- When the machine reboots login as pi with whatever password you selected.
- Noobs - A way to try all the main ones in one re-imagiable download.
- Raspbian “wheezy” - Recommended, with development tools.
- Soft-float Debian “wheezy” - Same as Raspbian but compiled for the slower soft-float hardware. Used for Oracle JVM version 7 or less.
- Arch Linux ARM - Boots in 10 seconds but definitely not for beginners.
- Pidora - Fedora.
- RISC OS - Acorn.
Introduction: Concepts, MVC architecture and Active Records. Part 1
Yii Architectural Review. Yii is scalable, supports CRUD actions, MVC but is not classed as an enterprise application framework because it doesn’t support transactions, no business rules or constraints, no workflow control. Part 4