[Buildroot] [PATCH 3/3] pi4j: new package

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Lucas De Marchi,

On Fri, 10 Jan 2014 17:50:22 -0200, Lucas De Marchi wrote:

> Add pi4j using its released binaries. The java archives are a bit
> different than other packages. Since they are coming already
> pre-compiled put them in /opt with the same layout as in raspbian,
> according to http://pi4j.com/install.html

I think this is quite certainly the first Java library for which we
have a package. Which JVM are you using to run this on the target? The
official Oracle JDK?

I think this package, like Python/Lua/Perl packages, should depend on
the selection of a JVM, be it the official Oracle JDK (for which a
package would have to be created), or JamVM, if this package is
actually compatible with it.

Regarding the installation in /opt, I'm not sure. The fact that
Raspbian installs it here is not that much of an argument to me (quite
the opposite, actually!).

On Ubuntu, the Java libraries are apparently installed
in /usr/share/java/, which seems a bit more sensible to me. The JNI
parts are installed in /usr/lib/jni/. See:

$ dpkg -L librxtx-java
[... skip documentation ...]
/usr/share/java
/usr/share/java/RXTXcomm-2.2pre2.jar
/usr/share/lintian
/usr/share/lintian/overrides
/usr/share/lintian/overrides/librxtx-java
/usr/lib
/usr/lib/jni
/usr/lib/jni/librxtxRaw-2.2pre1.so
/usr/lib/jni/librxtxI2C-2.2pre1.so
/usr/lib/jni/librxtxRS485-2.2pre1.so
/usr/lib/jni/librxtxSerial-2.2pre1.so
/usr/lib/jni/librxtxParallel-2.2pre1.so
/usr/share/java/RXTXcomm.jar
/usr/lib/jni/librxtxSerial.so
/usr/lib/jni/librxtxRS485.so
/usr/lib/jni/librxtxI2C.so
/usr/lib/jni/librxtxParallel.so
/usr/lib/jni/librxtxRaw.so


> diff --git a/package/pi4j/Config.in b/package/pi4j/Config.in
> new file mode 100644
> index 0000000..99736bf
> --- /dev/null
> +++ b/package/pi4j/Config.in
> @@ -0,0 +1,10 @@
> +config BR2_PACKAGE_PI4J
> +	bool "pi4j"
> +	depends on BR2_PACKAGE_RPI_USERLAND

Why this dependency?

As stated above, we should ensure that a JVM is selected here.

> +define PI4J_INSTALL_TARGET_CMDS
> +	$(INSTALL) -D -m 0644 $(@D)/lib/pi4j-core.jar \
> +		$(TARGET_DIR)/opt/pi4j/lib/pi4j-core.jar
> +	$(INSTALL) -D -m 0644 $(@D)/lib/pi4j-device.jar \
> +		$(TARGET_DIR)/opt/pi4j/lib/pi4j-device.jar
> +	$(INSTALL) -D -m 0644 $(@D)/lib/pi4j-example.jar \
> +		$(TARGET_DIR)/opt/pi4j/lib/pi4j-example.jar
> +	$(INSTALL) -D -m 0644 $(@D)/lib/pi4j-gpio-extension.jar \
> +		$(TARGET_DIR)/opt/pi4j/lib/pi4j-extension.jar
> +	$(INSTALL) -D -m 0644 $(@D)/lib/pi4j-service.jar \
> +		$(TARGET_DIR)/opt/pi4j/lib/pi4j-service.jar
> +endef

This can probably be improved a little bit:

PI4J_LIBS = core device example extension service

define PI4J_INSTALL_TARGET_CMDS
	$(foreach lib,$(PI4J_LIBS),\
		$(INSTALL) -D -m 0644 $(@D)/lib/pi4j-$(lib).jar $(TARGET_DIR)/opt/pi4j/lib/pi4j-$(lib).jar)
endef

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com