iPodLinux

iPodLinux is a modified build of uClinux, a fork of Linux for embedded devices (e.g. those without MMUs). Thus, many simple Linux applications or emulators can be easily ported or cross-compiled to iPodLinux with some modification. Note that this thread does NOT pertain to porting/creating podzilla2 modules but rather independent applications that can run from the terminal or be launched by podzilla2.

Here's a guide for setting up your iPodLinux compiling environment:
http://ipodlinux.org/wiki/Introduction_to_Compiling_for_iPodLinux

Here's a series of various code snippets that will help you with your port:
http://ipodlinux.org/wiki/Porting_Code_Snippets

Project ZeroSlackr is a project that currently maintains numerous iPodLinux ports/applications (see the SVN source code for ported examples):
http://sourceforge.net/projects/zeroslackr/
https://zeroslackr.svn.sourceforge.net/svnroot/zeroslackr/

Other uClinux projects you may want to take a look at are DSLinux and the Blackfin project. Most applications ported to the GP2X are also fair game (keep in mind the iPod's small screen size, limited input methods, and ~75Mhz processor). A few applications have also been ported over from the Rockbox project:
http://www.dslinux.org/
http://dslinux.gits.kiev.ua/trunk/user/
http://docs.blackfin.uclinux.org/doku.php?id=uclinux_on_blackfin
http://wiki.gp2x.org/wiki/Main_Page
http://www.rockbox.org/

Possibly useful wiki pages (may be outdated):
http://ipodlinux.org/wiki/Project_Status
http://ipodlinux.org/wiki/Emulation
http://ipodlinux.org/wiki/IPod_Programming
http://ipodlinux.org/wiki/CPP_Programming
http://ipodlinux.org/wiki/SDL_Programming
http://ipodlinux.org/wiki/Key_Chart
http://ipodlinux.org/wiki/PP5020
http://ipodlinux.org/wiki/PP5002
http://ipodlinux.org/wiki/GPIO
http://ipodlinux.org/wiki/ARMDev

More useful links:
http://lazyfoo.net/SDL_tutorials/index.php
http://fms.komkon.org/EMUL8/HOWTO.html
http://www.coranac.com/tonc/text/asm.htm

Please reply with more useful links for porting applications/emulators or edit the Introduction_to_Compiling_for_iPodLinux and Porting_Code_Snippets wiki pages.

If you port a new application/emulator to iPodLinux, please post it in the Recent Announcements section (one thread here for development and one thread there for latest release), make a new wiki page, and contact me (as I might add it to Project ZeroSlackr).

~Keripo

Hi Keripo,
I noticed a couple of minor errors in the Wiki "Introduction to Compiling for IPodLinux". I can't figure out how to edit the Wiki, so I am posting it here.

1. In the section Loader2, number "2", it says: cd loader2. It should be: cd ipodloader2.

2. To use the 3.4.3 toolchain in the section Booting Slax, number 5, it (correctly) says that to use the command:
export PATH=/usr/local/arm-uclinux-tools2/bin:$PATH
But later in the document (Building other Applications) it (incorrectly) says to use:
export PATH=/usr/local/arm-elf-tools2/bin:$PATH

3. I think the instructions for the 2.95.3 toolchain are inconsistent, but I didn't get a chance to see which one is correct.

4. In the Kernel section, I followed the instructions twice, but never got the Image file described in step 7.

I wanted to say that you have done a great job with all your work. I learned a lot here and had fun. My goal is to tether a small scanner to a small device running linux. I have learned that I need a device with USB host capabilities, so I'll be checking out linux on the Treo 650.

Peace out.

If you look at the "svn co ..." line, I have "loader2" put after the url. I guess it'd be less confusing if I didn't do that, so I'll change that, thanks ; )



Nice catch. The tutorial took a long time to write and obviously would also take a long time to test so I never did actually try out everything again from scratch. During the time of tutorial-writting I was using Windows XP and had Cygwin installed, so often I'd be typing "export PATH=/usr/local/arm-uclinux-elf-tools/bin:$PATH" or something like that.



Could you clarify what you mean by that?

By default, the 2.95.3 toolchain gets installed to /usr/local/bin so, if one were to not export any PATH variable, the default toolchain that gets used when you type "arm-elf-gcc" is the 2.95.3 toolchain. When you manually re-export the PATH variable, however, the shell looks in /usr/local/arm-uclinux-tools2/bin before it checks /usr/local/bin. Thus, it finds (and uses) the 3.4.3 toolchain instead. By re-exporting with /usr/local/bin forces the shell to first look there, thus forcing the 2.95.3 toolchain to be found first.

You'll have to describe your problem in greater detail, preferably in a different thread.



Unfortunately the iPod doesn't have USB host drivers written (except maybe for the 1G/2G iPod monos). You may want to check out the Rockbox project as they have done quite some extensive work with USB drivers.

~Keripo