What does the Special Developer Edition firmware means to you?

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The Special Developer Edition (SDE) firmware, released by Archos as a gesture to developers, is a very good starting point if you want to develop software safely on your Archos 5/7. The downside of installing this firmware is that you will lose your warranty, and you will also lose the ability to play any media protected by DRM (digital rights management) even if you revert back to an official firmware.

Here's a description of what the SDE firmware will do to your device:

  • It will overwrite 8 kb of flash memory with zeroes at the address 0x003f8000. This area of the flash memory holds the DRM keys that a 'normal' firmware needs to read protected contents. Historically, all firmwares included a copy of these keys, but starting with firmware 1.7.11 these keys are no longer included in the normal firmware line. This means that if you install the SDE firmware, the DRM keys will be erased, and they will not be written back if you revert to a normal firmware.
  • It will erase all data from your system partition (where all archos specific software is stored) and it will store the new rootfs on the data partition. The init kernel will boot from this new rootfs.
  • The new bootloader installed on your device will lock down some areas of flash memory (see table below). You will notice that init (at 0x210000) is not locked. This will allow you to create your own kernel and run it on the device. The new init shipped with the SDE is not signed, all other bootloader parts (boot0, boot1 and recovery) are still signed.
Address Size Locked (in bytes) Bootloader part
0x000000 65536 boot0
0x010000 65536 keystore
0x030000 131072 boot1
0x080000 1638400 recovery
0x3F8000 65536 DRM keys

These areas are locked down ONLY if you boot with the init kernel. If the recovery kernel is used, the lock down is not performed. This will allow you to fully revert to a normal firmware (except, of course, for the DRM keys).

The good news is that you will be able to revert to a normal firmware, at which point you will be able to perform a downgrade and switch to one of our patched firmwares.

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