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.
The custom firmware is configured to use the package repository at hummypkg.org.uk by default.
A package is a UNIX Archive (ar) file which itself contains three files:
- A file which just contains the string "2.0", a clue to the packaging system's roots.
- The files which make up the package.
- 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
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
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: firstname.lastname@example.org 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.
- The package name.
- Always set to optional for Humax packages.
- One of misc, net, devel, etc. full list
- The package version number of the format upstream_version[-opkg_version] more information
- Always mipsel for the HD/HDR Fox T2, and mips for the FoxSat.
- An email address or hummy.tv/wiki username.
- A list of dependencies for this package, optionally with version constraints see Debian documentation
- A description of the package. Continuation lines must be prefixed by white space.
- 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...
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#