Create Packages

The modified firmware includes a lightweight package management system called opkg (home page) which is similar to the Debian package management system (dpkg).

Coding your package

Most of the customised firmware is written in a language called Jim/TCL, See the Jim Manual HERE with other bits in C/C++ and the Humax runs a Linux operating system.

Package Repositories

The custom firmware is configured to use the package repository at hummypkg.org.uk by default.

Package Format

A package is a UNIX Archive (ar) file which itself contains three files:

debian-binary 

A file which just contains the string "2.0", a clue to the packaging system's roots.

data.tar.gz 

The files which make up the package.

control.tar.gz 

Package meta-information.

Creating a Package

The pkgtools package includes utilities for working with packages and can be used to create packages directly on the Humax itself. Before proceeding, install these utilities:

humax# opkg update
humax# opkg install pkgtools
humax# opkg install gzip

Next create a directory to hold your new package and create a directory within it called CONTROL, which will be used for the package meta-information:

humax# cd /mod/tmp
humax# mkdir my-first-package
humax# mkdir my-first-package/CONTROL

Note: Package names should not contain underscore (_) characters as these are used as delimiters in package file names. It is safest to stick to alpha-numeric characters and use - as a delimiter where appropriate, e.g. webif-iphone

Place the files which make up your package directly into the new package directory. Note that to save memory when running, compiled binaries should be stripped before packaging. In this example, we'll create a package which just installs a script called hello.

humax# cd /mod/tmp/my-first-package
humax# mkdir bin
humax# cat > bin/hello
#!/bin/sh

echo "Hello!"
^D
humax# chmod 755 bin/hello

Note: Files should be included relative to /mod (or /opt on the FoxSat) so in this example the bin/hello file will be installed as /mod/bin/hello

Create file package control file as CONTROL/control. Here's an example:

Package: jim-sqlite3
Priority: optional
Section: misc
Version: 0.71
Architecture: mipsel
Maintainer: af123@hummypkg.org.uk
Depends: jim(>=0.71-1),sqlite3
Description: Jim SQLite3 plugin.
 A plugin for the jim interpreter (a lightweight TCL interpreter) which
 provides access to SQLite3 databases (such as those used on the Humax).

The Debian project maintains documentation on the format of the control file which also applies to opkg packages, although some fields are not required.

Package 

The package name.

Priority 

Always set to optional for Humax packages.

Section 

One of misc, net, devel, etc. full list

Version 

The package version number of the format upstream_version[-opkg_version] more information

Architecture 

Always mipsel for the HD/HDR Fox T2, and mips for the FoxSat.

Maintainer 

An email address or hummy.tv/wiki username.

Depends 

A list of dependencies for this package, optionally with version constraints see Debian documentation

Description 

A description of the package. Continuation lines must be prefixed by white space.

Tags 

An optional field that contains a URL pointing to a source of further information

The CONTROL directory can also contain other package maintenance scripts such as preinst, postinst, prerm and postrm. See the Debian documentation for more details and examples. The scripts are called with various arguments during package maintenance operations. Many simple packages do not require any maintenance scripts.

Continuing with our example package, create the bare minimum control file:

humax# cat > CONTROL/control
Package: hello
Version: 1.0
Architecture: mipsel
Maintainer: af123
Description: hello
Tags: http://wiki.hummy.tv/wiki/Custom_Firmware_Overview/

The package can now be built using the opkg-pack command:

humax# cd /mod/tmp
humax# opkg-pack my-first-package
bin/
bin/hello
Packaged contents of /mod/tmp/my-first-package/ into /mod/tmp/my-first-package//../hello_1.0_mipsel.opk 532

The package can then be installed directly from the resulting file for testing.

humax# opkg install hello_1.0_mipsel.opk
Installing hello (1.0) to root...
Configuring hello.
humax# hello
Hello!
humax# opkg remove hello
Removing package hello from root...

If you have any packages which you'd like published in the hummypkg.org.uk repository, then email them to packages@hummypkg.org.uk.

Unpacking an existing package

The pkgtools package also contains a utility which can be used to unpack an existing package into a directory structure for editing or just for investigation, NOTE :- you need to install the gzip Custom Firmware package in order to use opkg-unpack

humax# cd /mod/tmp
humax# opkg download webif
Downloading http://hummypkg.org.uk/hdrfoxt2/base/webif_0.6.4_mipsel.opk.
Downloaded webif as ./webif_0.6.4_mipsel.opk.
humax# opkg-unpack webif_0.6.4_mipsel.opk
Unpacked to webif_0.6.4_mipsel

If you have a Debian-based Linux machine, opkg packages can be examined and manipulated using the dkpg-deb command.

wget http://hummypkg.org.uk/hdrfoxt2/base/busybox_1.19.3-3_mipsel.opk
dpkg-deb -x busybox_1.19.3-3_mipsel.opk <tmpdir>

Packing and Unpacking Bundled Packages

An OPK file contains the executable program /s and all the set-up scripts required for a single Custom Firmware package, However this single package may require other packages to be present in order to work. An OPB file contains the main package and all the peripheral packages require for it to run in a single file, the OPK’s are tarred together to form this file and can be viewed as follows :-

humax# /bin/untar multimode_0.0.1_mipsel.opb
Extracting from multimode_0.0.1_mipsel.opb
 Extracting file multimode_0.0.1_mipsel.opk
 Extracting file webif_0.8.9_mipsel.opk
 Extracting file mongoose_3.0-6_mipsel.opk
 Extracting file jim_0.71-1_mipsel.opk
 Extracting file jim-sqlite3_0.71-1_mipsel.opk
 Extracting file sqlite3_3.7.6_mipsel.opk
 Extracting file jim-cgi_0.4-1_mipsel.opk
 Extracting file jim-oo_0.71_mipsel.opk
 Extracting file jim-pack_0.71_mipsel.opk
 Extracting file service-control_1.0_mipsel.opk
 Extracting file busybox_1.19.3-2_mipsel.opk
 Extracting file lsof_4.82_mipsel.opk
 Extracting file epg_1.0.8_mipsel.opk
 Extracting file hmt_1.1.3_mipsel.opk
 Extracting file ssmtp_2.64_mipsel.opk
 Extracting file anacron_2.3-1_mipsel.opk
 Extracting file cron-daemon_1.18.3-1_mipsel.opk
 Extracting file rs_0.4.0_mipsel.opk
End of multimode_0.0.1_mipsel.opb
humax#