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Creating an Extension

This article assumes the user is comfortable at the command line. Using these instructions, the user will:

  • create temporary files and directories
  • output the final files to a temp directory
  • use make and squash file tools


  • Your source code and all dependencies
  • compiletc extension
  • squash file tools extension

Choosing an Extension name

Please take care with choosing extension names. eg Be aware of those using FAT filesystem see http://forum.tinycorelinux.net/index.php/topic,13428.msg84490.html#msg84490

Required info

  • The package maintainers (JW in particular) use the forum to post the most recent extension creation guidelines. You need to read the recent guidelines forum thread and the FAQ entry for submission
  • For information on creating icons, menu entries, setup scripts, .info and .dep files, please see iconmenuinfo.
  • Packaging kernel modules: thread.
  • Tiny Core v2.4+ uses extensions in .tcz format. Other formats are deprecated.
  • Tiny Core v2.7+ only uses the .tcz extension. There are no filename extension variants. If you don't know what that means … be thankful. Just create files ending in tcz.

Abbreviated steps

The Big Steps:

  1. configure/make/make install
  2. separate out docs, locale info, and development files
  3. include a copyright/license (if license requires it) in the packages. Most gpl do not need this compliance.
  4. squash up everything into your extension(s)
  5. write & place support files: dep, info, list, and md5 hash
  6. bcrypt/tar it all
  7. email it to the Tiny Core Team

Much can be scripted and the payoff is well worth it. For instance, steps 3-6 can be automated with tcztools (not an official TC tool). Just for the record:

*.a *.h *.la *.m4 *.pc -> dev extension (after --strip-debug) 
*.so* -> main extension (after --strip-unneeded) 


Before you begin, please do not have any build depend tczs like compiletc, lib* or *dev files ondemand. All depends for building need to be loaded thru onboot or manually such as

tce-load -i package

This means you do not not need to adjust your onboot list, but can use the APPS panel to download (only) packages and then install them when you need them

Use the compiletc extension when compiling your source - it includes the most common tools, all set up for tc (gcc, make, etc). If you are getting strange make errors, try the coreutils extension. Tar errors? Get the tar extension. And so on.

Please note that the standard install prefix for TC is /usr/local

Suggested compiler flags on x86 (for compatibility):

export CFLAGS="-march=i486 -mtune=i686 -Os -pipe"
export CXXFLAGS="-march=i486 -mtune=i686 -Os -pipe"
export LDFLAGS="-Wl,-O1"

Suggested compiler flags on x86_64 (for compatibility; see also the forum thread):

export CFLAGS="-mtune=generic -Os -pipe"
export CXXFLAGS="-mtune=generic -Os -pipe"
export LDFLAGS="-Wl,-O1"

Suggested compiler flags on RPi (discussed in this forum thread):

export CFLAGS="-Os -pipe"
export CXXFLAGS="-Os -pipe"
export LDFLAGS="-Wl,-O1"

If you wish to try to get a lower sized C++ app, you can try adding ”-fno-exceptions -fno-rtti” to CXXFLAGS. Use only on C++ applications, libraries should use the same flags as in CFLAGS above.

For apps that do not use threads (pthread_cancel), the following flag reduces binary size: ”-fno-asynchronous-unwind-tables”.

Flags Not-allowed (good performance, but likely won't work on other machines):

-march=native -mtune=native

On x86_64, Juanito has suggested that additional flags may help reduce size, but this may break some builds:

CC="gcc -flto -fuse-linker-plugin"
CXX="g++ -flto -fuse-linker-plugin"

Please refer to http://www.gentoo.org/doc/en/gcc-optimization.xml and http://gcc.gnu.org/onlinedocs/gcc/Invoking-GCC.html for more compiler flags info.

Setting pkg-config paths via “export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:/usr/lib/pkgconfig” is no longer required as the default in the latest extension includes ”/usr/{local,}/{lib,share}/pkgconfig”.

Example steps to configure and compile a package_name.tar.bz2:

tar xjvf package_name.tar.bz2
cd package_name
./configure --prefix=/usr/local
make -j3

Note: ”-j3” is meant for a 2 processor system. The general guideline is -jN where N is 1 more than the total number of processors available.

Create/update a date marker just in case your app doesn't support DESTDIR:

touch /tmp/mark

Install the application:

make DESTDIR=/tmp/package install

(see below, “When DESTDIR Fails” if needed.)

Note: some packages support “make install-strip”, which strips off debugging information. Jason W recommends doing so to save space. He also mentions that you can do it post-make with:

find . | xargs file | grep "executable" | grep ELF | grep "not stripped" | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null || find . | xargs file | grep "shared object" | grep ELF | grep "not stripped" | cut -f 1 -d : | xargs strip -g 2> /dev/null

Run these on your package directory tree before you tar it up.

All extension creators please note

If you don't need a startup script, then skip the next section. The TC system will create empty tce.installed/package_name files. You can ask for help IRC or on the tce Q&A if you are having issues getting your script working ok. You may wish to see how others have done it, for x86 see http://www.tinycorelinux.net/4.x/x86/tcz/src/

gutmensch provides the following set of rules:
  • Tiny Core special settings, e.g. root:staff for /usr/local/tce.installed and 775
  • Shared object lib files (end in .so or .so*) are classified as executables
  • Static object lib files (end in .a or .la) are classified as normal files, and so
  • All files root:root, 644 for files, 755 for executables, 755 for directories
  • Special settings varying on the software,
  • —-e.g. setuid, setgid for Xorg, read/write-only for root in /etc/private or /var/…,
  • —-special user like postfix or mysql, etc. within the extension or setup with the tce.installed/* script while booting.
  • [/usr/local]/etc/init.d/xyz scripts are usually system services and not user based services,
  • —-so the simple set here is: check for root user, if not, just fail.


  • If app/service can be run as a normal user (not as root!), make sure your init, start or extensions scripts
  • —are able to handle this. For example, query the $TCUSER variable and set the permissions accordingly when
  • —installing the extension. Or reconfigure the software so that it defaults to user writeable directories like $HOME, /tmp, etc.
@cups example:
  • Unordered List ItemSince the service is run as root either way, the init script should also fail when not run as root, which is the easiest solution.
  • Checkout the checkroot() helper function in /etc/init.d/tc-functions e.g. Try to use sudo in scripts as least as possible.

reference http://forum.tinycorelinux.net/index.php/topic,14988.msg85727.html#msg85727

aus9 writes:
  • There are many ways to build extensions. If you prefer the build script way, it is easy to build root:root by running the script as root. Extensions can not be loaded by root powers, so change your script to the following method, you can drop the .tcz off each nameX.tcz
su -c 'tce-load -i name1 name2' tc
  • To use wget as a normal user without leaving root try loading submitqc4 which autoloads wget then run
su -c '/usr/local/bin/wget -nc http://www.some-site/download/filename.tar.gz -O /tmp/tarball-name.tar.gz' tc
  • The wget.tcz is useful when you can't verify certificate so you can add –no-check-certificate into that last command, while busybox's wget might struggle.
  • When you check permissions sym links will show up as 777 which I have been advised is normal behaviour.

Adding Custom Startup Scripts

If your software needs a startup script then create the folder for it

mkdir -p /tmp/package/usr/local/tce.installed 

Next, create script as /tmp/package/usr/local/tce.installed/package_name if you would like to do something when the package is first installed or again mounted on boot.

A good pattern to follow would be to first rename /tmp/package/usr/local/etc/package_name.conf to package_name.conf.sample, and for your script to check always whether /usr/local/etc/package_name.conf exists, and if no, copy over /usr/local/etc/package_name.conf.sample into it. This is so that the application's configuration files are fully writable in the natural path, without having to resort to weird paths that you determine on your own.


cd /usr/local/etc/ [[ ! -e nano.rc ]] && cp -p nano.rcsample nano.rc

Warning: If you don't do this now, these configuration files would be read-only. Please read iconmenuinfo wiki page for more information on creating wbar icons, menu entries, setup scripts, .info and .dep files.

Next, follow these commands to make script executable and with correct permissions.

sudo chown -R root:staff /tmp/package/usr/local/tce.installed 
sudo chmod -R 775 /tmp/package/usr/local/tce.installed 

Watch out for persistence–If your startup script is creating a home file and the user has persistence, you may like to create an IF-THEN script to check if file already exists as a part of the startup script.

Extra steps may also be needed see link


Please check the license condition. Although we can strip a number of documents from the main tcz and have a separate doc.tcz, this is not always possible. eg if you see a file called COPYING and it has a section like this:

The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software. 

Please create and copy the relevant file, eg:

mkdir -p /tmp/package/usr/local/share/doc/package 
cp -f COPYING /tmp/package/usr/local/share/doc/package

Creating a .tcz

If the program supports DESTDIR (most do) the files will be installed in /tmp/package, but configured for /usr/local. In this case, create extension like this:

cd /tmp 
mksquashfs package program_name.tcz 
cd /tmp/package

Next create the list of files in the extension, it will be submitted with the extension:

find usr -not -type d > program_name.tcz.list

As a final step, remove the packed files from /tmp/package:

rm -rf usr

When DESTDIR Fails

Just about all applications support the use of DESTDIR on the make line (as above). There are those that don't, however. If your application does not support DESTDIR, it will likely install into subdirectories of root, rather than tmp.

One possible solution from the forums, by Jason W, uses a time stamp, find, and tar.

As above, set the ./configure installation prefix as normal. Then be sure to create a time stamp after make, but do it just before make install. Use find to list all the newly installed files, and then gather those files up using tar.

./configure --prefix=/usr/local 
touch /tmp/mark #in case DESTDIR fails 
make install DESTDIR=/tmp/pkg #DESTDIR may not work ... 
find /usr/local -newer /tmp/mark -not -type d > /tmp/list 
tar -T /tmp/list -czvf /tmp/someapp.tar.gz

For TC past 2.4, you will need to unzip the tar file, and then use mksquashfs to create your extension:

mkdir /tmp/pkg 
cd /tmp/pkg 
tar -xf /tmp/someapp.tar.gz #'install' the extension in tmp 
cd /tmp 
mksquashfs pkg/ someapp.tcz

Be careful using touch/find -newer method. There are files just copied by installer from the source package, like configuration files, header files, scripts, doc files, images, etc. with original date, therefore they are not detected. Check installer messages!


Test out your new extension(s) by manually loading them after booting TC with the cheatcodes:

base norestore

Load your extension, and check:

  1. all dependencies loaded?
  2. menu item works? wbar/desktop icons work?
  3. program actually runs?

It is easy to leave out a required dependency from your .dep file. Do use base norestore, and check the dependencies in particular.

If you are planning on submitting your extension for inclusion in the repository, you should run the extension audit script as well. The script is now available as an extension called submitqc.tcz. (Remember that if you want to download the script from the forum, you need to be logged in to see the links.)



Smaller extensions reduce 'bloat' in Tiny Core. To help out: * move translations and other locale data into a locale extension (myprogram-locale.tcz) * move documentation and help files into a doc extension (myprogram-doc.tcz) * rather than including docs in your extension, use the info file to list official online docs.

Required Files

Submissions must include:

  • the extension file (.tcz)
  • a list of its contents (.tcz.list)
  • an md5 sum (.tcz.md5.txt)
  • an info file describing its contents (.tcz.info) - this content is standardized. Visit the repository for examples.
  • a dependency list, if necessary (.tcz.dep)
  • If the source is under the GPL license, include the source as well.
  • a .tcz.zsync (autogenerated with submitqc4)

It is not required, but certainly recommended, that you include any additional build instructions in a plain text file for future reference, mentioning such things as which extensions are required to build the package and what compile flags were used. This can be done in a file named “build-dep”. For example, the build-dep file for urxvt looks like this:

Required extensions to build: 

256-color patch applied  

Additional configure options: 
  * -enable-xft 
  * -with-codesets=none 
  * -disable-afterimage   
  * -disable-xterm-scroll   
  * -disable-next-scroll   
  * -disable-perl

This is just an example, and the format can be however you desire. Again, this is not required, but is a helpful practice, as it will help if you update the extension for a new release.

.tcz.info example

Title:          package_name.tcz 
Description:    package description 
Version:        0.1 
Author:         Author(s) name 
Original-site:  http://website.domain 
Copying-policy: GPL v1 
Size:           100K (of the package) 
Extension_by:   Your nickname 
Tags:           tag1 tag2 tag3 ... 
Comments:       Information that you consider useful 
                for those who will be use this package. 
                Compiled for TC 4.x                 
                PPI Compatible 
Change-log:     2012/00/01 First version, 0.1
                2012/01/01 Short change description 
Current:        2012/02/01 Current short change description 

If the package contains a program, the best choice for its name is the bin name (this will ensure that program start directly if you load package ondemand). Alternatively, it is better to use suffixes on standard name of content instead of prefixes to customize the package name because in the main type of research in appbrowser (“search”) you can only omit final letters. e.g., if the package name is gold_eggs, if I search eggs I do not find it, if I search Gold I find it (case is not important).

In field “Comments” string “PPI Compatible” (if the package is compatible with “Persistent Personal Installation” mode, usually if we have used /usr/local directory as a installation prefix) seems no longer to be specified since this type of operation has been removed from 4.x

.tcz.dep example

If submitting a package called fruit.tcz your depend should be a simple list of main dependencies, one tcz per line with no indentation. Meaning it has no gaps or “tree” structure

Right example: fruit.tcz.dep

apple.tcz banana.tcz 

Wrong example: fruit.tcz.dep


If package has no dependencies do not submit any file but in email please alert tcz checker that there are no dependencies.

Send to

Have you run the extension audit script to test your extension? If so, create a gzip archive. For example, if all the required files are in one directory, the command would look like this:

tar zcf extension.tar.gz *

Send the resulting extension.tar.gz file to tcesubmit _at_ gmail _dot_ com.

For piCore (Raspberry Pi) extensions send it to picoresubmit _at_ gmail _dot_ com.

Files part of an extension package are Gmail neutral and accepted for delivery, no need to encrypt. For more details, read the guildelines forum thread.