Wiki:help/howtos/development/developer_information/package_development_start/example_2

Example 2: par2cmdline

This second example is a cmdline program for creating and using PAR2 files to detect damage in data files and repair them if necessary.

More info about par2cmdline can be found here.

Be aware that while trying this package on my 7270v3 I got a “Segmentation fault”, but didn’t look further for a solution (using par2cmdline-0.1 might be an option).

Build manually

The toolchain should be part of the search path. This is achieved with the PATH= export command below.
You can look with echo $PATH what the current search path variable is.

mkdir par2cmdline
cd par2cmdline
wget http://sourceforge.net/projects/parchive/files/par2cmdline/0.4/par2cmdline-0.4.tar.gz
tar xfvz par2cmdline-0.4.tar.gz
cd par2cmdline-0.4
wget http://sourceforge.net/p/parchive/bugs/_discuss/thread/e9911edb/b6aa/attachment/par2cmdline-0.4-gcc4.patch
patch -p0 < par2cmdline-0.4-gcc4.patch
./configure --help
export CC="mipsel-linux-gcc"
export CXX="mipsel-linux-uclibc-g++-wrapper"
export PATH=/home/freetz/freetz-trunk/toolchain/target/bin/:$PATH
./configure \
--prefix=/usr \
--build=i686-pc-linux-gnu \
--host=mipsel-linux
make
ls -la par2 *
file par2 *
mipsel-linux-strip par2
ls -la par2 *
file par2 *

^* Optional, to see the impact of stripping. The file command should also show the executable is a MIPS executable.

Next you might want to see that "make clean" properly works for this package. This will (should) remove all generated files during make.

cd ~/freetz-trunk/par2cmdline/par2cmdline-0.4/
make clean

The Freetz environment makes use of "make clean" of each package to remove all generated files during compiling.
So testing this with this manual created package should give an idea what happens giving a "make clean" within Freetz.

Add package to Freetz

In this example we will create the directory and file structure ourselves.

For each new package a directory under ~/freetz-trunk/make/ should be created with a minimum of two files:

`--make
     `--<package-name>
           |-- Config.in
            `-- <package-name>.mk

Optional there are more directories and files in case e.g. patches are needed like with par2cmdline.

Lets create the directory structure and the two files for Par2cmdline:

cd /home/freetz/freetz-trunk/
mkdir –p /home/freetz/freetz-trunk/make/par2cmdline/patches/
vi /home/freetz/freetz-trunk/make/par2cmdline/Config.in

config FREETZ_PACKAGE_PAR2CMDLINE
        bool "par2cmdline 0.4"
        default n
        help
                Cmdline program for creating and using PAR2 files to detect damage in data files and repair them if necessary.

The indents should be replaced with tabs.

For the second file keep in mind that $(pkg) will have the value par2cmdline, and $(PKG) with be PAR2CMDLINE.

vi /home/freetz/freetz-trunk/make/par2cmdline/par2cmdline.mk

$(call PKG_INIT_BIN, 0.4)
$(PKG)_SOURCE:=$(pkg)-$($(PKG)_VERSION).tar.gz
$(PKG)_SOURCE_MD5:=1551b63e57e3c232254dc62073b723a9
$(PKG)_SITE:=http://sourceforge.net/projects/parchive/files/$(pkg)/$($(PKG)_VERSION)/

$(PKG)_BINARY:=$($(PKG)_DIR)/par2
$(PKG)_TARGET_BINARY:=$($(PKG)_DEST_DIR)/usr/sbin/par2
$(PKG)_CATEGORY:=Unstable

$(PKG_SOURCE_DOWNLOAD)
$(PKG_UNPACKED)
$(PKG_CONFIGURED_CONFIGURE)

$($(PKG)_BINARY): $($(PKG)_DIR)/.configured
        $(SUBMAKE) -C $(PAR2CMDLINE_DIR) \
                CXX="$(TARGET_CXX)"

$($(PKG)_TARGET_BINARY): $($(PKG)_BINARY)
        $(INSTALL_BINARY_STRIP)

$(pkg):

$(pkg)-precompiled: $($(PKG)_TARGET_BINARY)

$(pkg)-clean:
        -$(SUBMAKE) -C $(PAR2CMDLINE_DIR) clean

$(pkg)-uninstall:
        $(RM) $(PAR2CMDLINE_TARGET_BINARY)

$(PKG_FINISH)

The indents should be replaced with tabs.

wget http://sourceforge.net/p/parchive/bugs/_discuss/thread/e9911edb/b6aa/attachment/par2cmdline-0.4-gcc4.patch -O 100-gcc4.patch
mv 100-gcc4.patch make/par2cmdline/patches/

Note: Also tried with parameter -P make/par2cmdline/patches , but this wasn't accepted with the wget command, so I had to move the patch to the correct location.

Explanation of the lines:

$(call PKG_INIT_BIN, 0.4)

From this line the package version is determined. In this case 0.4

$(PKG)_SOURCE:=$(pkg)-$($(PKG)_VERSION).tar.gz

This variable translate to the source file name that will be downloaded and used further. Here it will be PAR2CMDLINE_SOURCE:=par2cmdline-0.4.tar.gz

$(PKG)_SOURCE_MD5:=1551b63e57e3c232254dc62073b723a9

This is the md5 hash value to verify successful download. PAR2CMDLINE_SOURCE_MD5:=1551b63e57e3c232254dc62073b723a9

$(PKG)_SITE:=http://sourceforge.net/projects/parchive/files/$(pkg)/$($(PKG)_VERSION)/

The download url. PAR2CMDLINE_SITE:= http://sourceforge.net/projects/parchive/files/par2cmdline/0.4/

$(PKG)_BINARY:=$($(PKG)_DIR)/par2

The binary file as result of compiling the package. Here it will be PAR2CMDLINE_BINARY:= source/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/par2
(source/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/ is where the source is unpacked before it is compiled)

$(PKG)_TARGET_BINARY:=$($(PKG)_DEST_DIR)/usr/sbin/par2

The location in the Freetz structure where the stripped binary will be saved. PAR2CMDLINE_TARGET_BINARY:= packages/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/root/usr/sbin/par2

$(PKG)_CATEGORY:=Unstable

This line determines where in the ‘menuconfig’ this package will be located. Without this line the package will be located in ‘package’.
The following options are possible ‘Unstable’, ‘Web interfaces’, and ‘Debug helpers’.

$(PKG_SOURCE_DOWNLOAD)

This line triggers the download of the package. It will be downloaded to ./dl/par2cmdline-0.4.tar.gz

$(PKG_UNPACKED)

This line not only unpack the download, but also applies any patches that are available in make/par2cmdline/patch/*

$(PKG_CONFIGURED_CONFIGURE)

This will indicate that the ./configure step needs to be performed, and initiate the ./configure step.

The lines below have the structure of Makefiles:

target: dependencies
[tab] system command

$($(PKG)_BINARY): $($(PKG)_DIR)/.configured
        $(SUBMAKE) -C $(PAR2CMDLINE_DIR) \
                CXX="$(TARGET_CXX)"

This will initiate make with the specified CXX compiler as parameter. PAR2CMDLINE : source/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/.configured

make -j2 -C source/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4 CXX="mipsel-linux-uclibc-g++-wrapper"

$($(PKG)_TARGET_BINARY): $($(PKG)_BINARY)
        $(INSTALL_BINARY_STRIP)

Will strip the binary file. This will remove any unnecessary data from the executable to make it smaller. Something that is preferred for embedded systems with small flash space. packages/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/root/usr/sbin/par2 : source/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/par2

$(pkg):

par2cmdline:

$(pkg)-precompiled: $($(PKG)_TARGET_BINARY)

par2cmdline-precompiled: packages/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/root/usr/sbin/par2

$(pkg)-clean:
        -$(SUBMAKE) -C $(PAR2CMDLINE_DIR) clean

par2cmdline-clean:

make -C source/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4 clean

$(pkg)-uninstall:
        $(RM) $(PAR2CMDLINE_TARGET_BINARY)

par2cmdline-uninstall:

rm -f packages/target-mipsel_gcc-4.6.4_uClibc-0.9.32.1/par2cmdline-0.4/root/usr/sbin/par2

$(PKG_FINISH)

Ends the make script.

Create new image with added package

Like normal with creating an image execute make menuconfig and select your router model and all options and packages to be included.
First select two additional libraries that are needed for par2cmdline:
Shared libraries ---> C++ ---> [*] libstdc++ (libstdc++-6.0.x.so)
and
Shared libraries ---> C++ ---> [*] uClibc++ (libuClibc++-0.2.3.so).
It is also possible to automatically get this package selected using the files we created. This is something shown in example 3.
The newly added package is located in: Packages ---> Unstable ---> [*] par2cmdline 0.4.

Testing

Lets see if "make clean" works as expected. This should bring the state back to like it was before the "make" command.

cd ~/freetz-trunk/
make clean

Preparing New Package for Public Integration to Freetz Trunk

In order to create a file which displays the changes which would be needed in freetz to add your package, issue the following commands:

svn add make/par2cmdline
svn diff ./make > patchfile

In our case "patchfile" may be called "par2cmdline". Please note that there is no need for an extension here. You may only need an extension (e.g. .txt) for uploading it in the IPPF, because else it would not be recognized as a valid file for upload.

In addition you could even create a ready (and compressed) package of the two files which you had edited above:

tar cfz par2cmdline.tar.gz make/par2cmdline --exclude .svn
tar tfz par2cmdline.tar.gz