Difference between revisions of "EmBIOS"

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{{Template:Outdated|reason=emBIOS was discontinued on {{#dateformat:2011-03-25}} and superseded by [[emCORE]]}}
 
[[File:Embios.jpg|115px|thumb|right|emBIOS on the 4G Nano]]
 
[[File:Embios.jpg|115px|thumb|right|emBIOS on the 4G Nano]]
emBIOS is best described as a hardware abstraction with threading and debugging capabilities built in. It simplifies development immensely by integrating drivers for all the iPods. Before drivers were scattered throughout multiple tools built for multiple iPods. If there was a bug fix for a driver, it would have to be applied in many different places. emBIOS attempts to solve this problem by providing a syscall interface that is standard throughout all iPod generations. This means that a build of a tool can work across generations as long as it is run on a native emBIOS. This allows for maximum code reuse.
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emBIOS ('''em'''bedded '''BIOS''') is best described as a hardware abstraction with threading and debugging capabilities built in. It was superseded by [[emCORE]]. It simplified development immensely by integrating drivers for all the iPods. Before drivers were scattered throughout multiple tools built for multiple iPods. If there was a bug fix for a driver, it would have to be applied in many different places. emBIOS attempted to solve this problem by providing a syscall interface that is standard throughout all iPod generations. This means that a build of a tool can work across generations as long as it is run on a native emBIOS. This allows for maximum code reuse.
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emBIOS was designed with portability in mind. It should have also been able to be run on other devices like the BeagleBoard if someone would have ported the necessary drivers.
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If you're curious about how emBIOS worked, you can browse its last SVN revision before its official death [http://websvn.freemyipod.org/listing.php?repname=freemyipod&path=/embios/&rev=672&peg=672 here].
  
If you're curious about how emBIOS works, you can browse it's SVN folder [http://websvn.freemyipod.org/listing.php?repname=freemyipod&path=/embios/&#a70ba5517efd721bf4f2b7b4285a23990 here]. The emBIOS trunk has temporarily abandoned support for the [[Nano 4G]] since there was a holdup concerning it's timer. 4G development continues in the '4g_compat' branch. It will be merged in as soon as this holdup is solved.
 
 
==Building==
 
==Building==
If you want to try it out on your own iPod, there are automatic builds but you might as well just check out the SVN and compile it yourself. After all, emBIOS itself doesn't do much except print out its version string to the console. You must put something in main.c if you want it to do anything. Here are the basic steps to getting emBIOS up and running on your iPod:
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If you want to try it out on your own iPod, there are automatic builds on [http://builds.freemyipod.org/ our buildserver], but you might as well just check out the [[SVN]] and compile it yourself. Here are the basic steps to compiling emBIOS for your iPod:
 
* Check out the Freemyipod [[SVN]].
 
* Check out the Freemyipod [[SVN]].
* Build the UCL tool in the root of the SVN using make. You will need access to the UCL libraries to build this.
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* Build the UCL tool in the folder tools/ucl of the SVN using make and copy those tools to a place in your path.
 
* Make sure you have the arm-eabi toolchain. You can easily build this using the rockboxdev.sh script in the tools directory of the Rockbox SVN.
 
* Make sure you have the arm-eabi toolchain. You can easily build this using the rockboxdev.sh script in the tools directory of the Rockbox SVN.
* If you are on a Nano 2G, build the trunk using 'make ipodnano2g'. If on a Nano 4G, build the 4g_compat branch using 'make ipodnano4g'.
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* You can compile emBIOS for all targets ('make') or for only some ('make target1 target2'). You can find out the target names on [http://builds.freemyipod.org/ the buildserver]
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* If your toolchain prefix is not 'arm-none-eabi-' but something different (like 'arm-elf-eabi-' if you compile it with a toolchain created with the rockboxdev script) you can set the CROSS variable to your prefix.
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So to compile for the iPod nano 2g with your toolchain prefixed with arm-elf-eabi- do:
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<code>CROSS=arm-elf-eabi- make ipodnano2g</code>
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==Using==
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To communicate with emBIOS use the embios.py python script in the [http://websvn.freemyipod.org/listing.php?repname=freemyipod&path=/embios/trunk/tools/&rev=672&peg=672 /embios/trunk/tools] folder of our SVN. You need to have libusb, python and pyusb 1.x for this to work. Simply run embios,py without any arguments to get a list of possible commands. You can upload and download from/to the memory, read the i2c bus, run emBIOS applications or complete firmware files and much more. Just try it out!

Latest revision as of 18:59, 25 March 2011

Warning The information and/or topic discussed here is not up to date.

emBIOS was discontinued on 2011-03-25 and superseded by emCORE

emBIOS on the 4G Nano

emBIOS (embedded BIOS) is best described as a hardware abstraction with threading and debugging capabilities built in. It was superseded by emCORE. It simplified development immensely by integrating drivers for all the iPods. Before drivers were scattered throughout multiple tools built for multiple iPods. If there was a bug fix for a driver, it would have to be applied in many different places. emBIOS attempted to solve this problem by providing a syscall interface that is standard throughout all iPod generations. This means that a build of a tool can work across generations as long as it is run on a native emBIOS. This allows for maximum code reuse.

emBIOS was designed with portability in mind. It should have also been able to be run on other devices like the BeagleBoard if someone would have ported the necessary drivers.

If you're curious about how emBIOS worked, you can browse its last SVN revision before its official death here.

Building

If you want to try it out on your own iPod, there are automatic builds on our buildserver, but you might as well just check out the SVN and compile it yourself. Here are the basic steps to compiling emBIOS for your iPod:

  • Check out the Freemyipod SVN.
  • Build the UCL tool in the folder tools/ucl of the SVN using make and copy those tools to a place in your path.
  • Make sure you have the arm-eabi toolchain. You can easily build this using the rockboxdev.sh script in the tools directory of the Rockbox SVN.
  • You can compile emBIOS for all targets ('make') or for only some ('make target1 target2'). You can find out the target names on the buildserver
  • If your toolchain prefix is not 'arm-none-eabi-' but something different (like 'arm-elf-eabi-' if you compile it with a toolchain created with the rockboxdev script) you can set the CROSS variable to your prefix.

So to compile for the iPod nano 2g with your toolchain prefixed with arm-elf-eabi- do:

CROSS=arm-elf-eabi- make ipodnano2g

Using

To communicate with emBIOS use the embios.py python script in the /embios/trunk/tools folder of our SVN. You need to have libusb, python and pyusb 1.x for this to work. Simply run embios,py without any arguments to get a list of possible commands. You can upload and download from/to the memory, read the i2c bus, run emBIOS applications or complete firmware files and much more. Just try it out!